Category Archives: Science

Homeostasis And The Constancy Principle – We Are All Creatures Of Comfort Even When We Go Out Of Our Comfort Zone

It is autumn in our part of the world, and the first chills are in the air in the late evening and early morning, and the family discussed last night the need to get out our warm clothes from storage in readiness for the approaching winter, in order to be well prepared for its arrival. After sharing in the fun of Easter Sunday yesterday and eating some chocolate eggs with the children, a persistent voice in my head this morning instructed me to eat less than normal today to ‘make up’ for this out of the normal chocolate eating yesterday. It is a beautiful sunny day outside as I write this, and I feel a strong ‘urge’ to stop writing and go out on a long cycle ride because of it, and have to ‘will’ these thoughts away and continue writing, which is my routine activity at this time of morning. After a recent health scare I have been checking on my own physical parameters with more care than normal, and found it interesting when checking what ‘normal’ values for healthy folk are, that most healthy folk have fairly similar values for things like blood glucose, blood pressure, cholesterol concentrations and other such parameters, and that there are fairly tight ranges of values of each of these which are considered normal and a sign of ‘health’, and if one’s values are outside of these, it is a sign of something wrong in the working of your body that needs to be treated and brought back into the normal range either by lifestyle changes, medication, or surgical procedures. All of these got me thinking about the regulatory processes that ensure that the body maintains its working ‘parts’ in a similar range in all folk, and the concept of homeostasis, which as a regulatory principle explains and underpins the maintenance of this ‘safe zone’ for our body’s multiple activities, including the sensing of any external or internal changes which could be associated with the potential for one of the variables to go out of the ‘safe zone’, and initiates changes either behaviourally or physiologically which attempt to bring the variable at risk back into the ‘safe zone’ either pre-emptively or reactively.

Homeostasis is defined scientifically as the tendency towards a relatively stable equilibrium between inter-dependent elements. The word was generated from the Greek concepts of ‘homiois’ (similar) and ‘stasis’ (standing still), creating the concept of ‘staying the same’. Put simply, homeostasis is the property of a system whereby it attempts to maintain itself in a stable, constant condition, and resists any changes or actions on the system which may change or destabilize the stable state. It’s origins as a concept were from the ancient Greeks, with Empedocles in around 400 BC suggesting that all matter consisted of elements which were in ‘dynamic opposition’ or ‘alliance’ with each other, and that balance or ‘harmony’ of all these elements was necessary for the survival of the individual or organism. Around the same time, Hippocrates suggested that health was a result of the ‘harmonious’ balance of the body’s elements, and illness due to ‘disharmony’ of the elements which it was made up of. Modern development of this concept was initiated by Claude Bernard in the 1870’s, who suggested that the stability of the body’s internal environment was ‘necessary for a free and independent life’ and that ‘external variations are at every instant compensated for and brought into balance’, and Walter Cannon in the 1920’s first formally called this concept of ‘staying the same’ homeostasis. Claude Bernard actually initially used the word ‘constancy’ rather than homeostasis to describe the concept, and interestingly, a lot of Sigmund Freud’s basic work on human psychology was based on the need for ‘constancy’ (though he did not cross-reference this more physiological / physical work and concepts), and that everyone’s basic needs were for psychological constancy or ‘peace’, and when one had an ‘itch to scratch’ one would do anything possible to remove the ‘itch’ (whether it be a new partner, a better house, an improved social status, or greater social dominance, amongst other potentially unrequited desires), and further that one’s ‘muscles are the conduit through which the ego imposes its will upon the world’. He and other psychologists of his era suggested that if an ‘itch’, urge or desire was not assuaged (and what causes these urges, whether a feeling of inadequacy, or previous trauma, or a desire for ‘wholeness’, is still controversial and still not clearly elicited even today), the individual would remain out of their required ‘zone of constancy’, and would feel negative emotions such as anxiety, irritation or anger until the urge or desire was relieved. If it was not relieved for a prolonged period this unrequited ‘itch’ could lead to the development of a complex, projection or psychological breakdown (such as depression, mania, anxiety, personality disorder or frank psychosis). Therefore, as much as there are physical homeostasis related requirements, there are potentially also similarly psychological homeostasis related requirements which are being reacted to by the brain and body on a continuous basis.

Any system operating using homeostatic principles (and all our body systems do so) has setpoint levels for whatever substance or process is being regulated in the system, and boundary conditions for the substance or process which are rigidly maintained and cannot be exceeded without a response occurring which would attempt to bring the activity or changes to the substance or process back to the predetermined setpoint levels or within the boundary conditions for them. The reasons for having these set boundary conditions are protective, in that if they were exceeded, the expectation would be the system would be damaged if the substance or process being regulated (for example, oxygen, glucose, sodium, temperature, cholesterol, or blood pressure, amongst a whole host of others) was used up too quickly or worked too hard, or was allowed to build up to toxic / extremely high levels or not used enough to produce life-supporting substrates or useable fuels, which would endanger the life and potential for continued activity of the system being monitored. For example, oxygen shortage results in death fairly quickly, as would glucose shortage, while glucose excess (known as diabetes) can also result in cellular and organ damage, and ultimately death if it is not controlled properly. In order for any system to maintain the substance or process within homeostasis-related acceptable limits, three regulatory factors (which are all components of what is known as a negative feedback loop) are required to be components of the system. The first is the presence of a sensory apparatus that can detect either changes in whatever substance or process is being monitored, or changes in the internal or external environment or other systems which interact with or impact on the substance or process being monitored. The second is a control structure or process which would be sent the information from the sensory apparatus, and would be able to make a decision regarding whether to respond to the information or to ignore it as not relevant. The third is an ‘effector’ mechanism or process which would receive commands from the control structure after it had made a decision to initiate a response in response to the sensed perturbation potentially affecting the system it controls, and make the changes to the system decided upon by the control structure in order to maintain or return the perturbed system to its setpoint value range.

The example of temperature regulation demonstrates both the complexity and beauty of homeostasis in regulating activity and protecting us on a continuous basis from harm. Physiological systems in most species of animals are particularly sensitive to changes in temperature and operate best in a relatively narrow ranges of temperature, although in some species a wider range of temperatures is tolerated. There are two broad mechanisms used by different organisms to control their internal temperature, namely ectothermic and endothermic regulation. Ectothermic temperature regulators (also known as ‘cold-blooded’ species), such as the frog, snake, and lizard, do not use many internal body processes to maintain temperature in the range which is acceptable for their survival, but rather use external, environmental heat sources to regulate their body temperature. If the temperature is colder, they will use the sun to heat themselves up, and if warm, they will look for shadier conditions. Ectotherms therefore have energy efficient mechanisms of maintaining temperature homeostasis, but are more susceptible to vagaries in environmental conditions compared to endotherms. In contrast, endotherms (also known as ‘warm-blooded’ species), into which classification humans fall, use internal body activity and functions to either generate heat in cold environments or reduce heat in warm conditions. In endotherms, if the external environment is too cold, and if the cold environment impacts on body temperature, temperature receptors measuring either surface skin temperature or core body temperature will send signals to the brain, which subsequently initiates a shiver response in the muscles, which increases metabolic rate and provides greater body warmth as a by-product of fuel / energy breakdown and use. If environmental temperature is too warm, of if skin or core temperature is too high, receptors will send signals to brain areas which initiates a chain of events involving different nerve and blood-related control processes which result in increased blood flow to the skin by vasodilatation, thereby increasing blood cooling capacity and sweat rate from the skin, thus producing cooling by water evaporation. All these endotherm associated heating and cooling processes utilize a large amount of energy, so from an energy perspective are not as efficient as that of ectotherms, but they do allow a greater independence from environmental fluctuations in temperature. It must be noted that endotherms also use similar behavioural techniques to ectotherms, such as moving into shady or cool environments if excessively hot, but as described above, can tolerate a greater range of environmental temperatures and conditions. Furthermore, humans are capable of ‘high level’ behavioural changes such as putting on or taking off clothes, in either a reactive or anticipatory way. It is evident therefore that for each variable being homeostatically monitored and managed (on a continuous basis) there are a complex array of responsive (and ‘higher-level’ pre-emptive) options available with which to counteract the potential or actual ‘movement’ of the variable beyond its ‘allowed’ metabolic setpoints and ranges.

There are a number of questions still to be answered regarding how homeostasis ‘works’ and how ‘decisions’ related to homeostasis occur. It is not clear how the regulatory mechanisms know which variable they ‘choose’ to defend as a priority. Brain oxygen would surely be the most important variable to ‘defend’, as would perhaps blood glucose levels, but how decisions are made and responses initiated for these variables preferentially, which may impact negatively on other systems with their own homeostatic requirements, is not clear. Furthermore, there is the capacity for ‘conflict’ between physical and psychological homeostatic mechanisms when homeostatic-related decisions are required to be made. For example, one’s ego may require one to run a marathon to fulfill a need to ‘show’ one’s peers that one is ‘tough’ by completing such a challenging goal, but doing so (running the marathon) creates major physical stress for and on the physical body. Indeed, some folk push themselves so hard during marathons that they collapse, even if they ‘feel’ warning signs of impending collapse, or of an impending heart attack, and choose to keep running despite these symptoms. To these folk, the psychological need to complete the event must be greater than the physical need to protect themselves from harm, and their regulatory decision-making processes clearly valences psychological homeostasis to be of greater importance than physiological homeostasis when deciding to continue exercising in the presence of such warning symptoms. However, running a marathon, while increasing physical risk of catastrophic physical events during the running of it, if done on a repetitive basis has positive physical benefits, such as weight loss and increased metabolic efficiency of the heart, lungs, muscles and other organ structures, along with enhanced psychological well-being which would be derived from achieving the set athletic performance-related goals. Therefore, ‘decision-making’ on an issue such as running a marathon is complex from a homeostasis perspective, with both short and long term potential benefits and harmful consequences. How these contradictory requirements and factors are ‘decided upon’ by the brain when attempting to maintain both psychological and physical homeostasis is still not clear.

A further challenge to homeostatic regulation is evident in the examples of when one has a fever, where a high temperature may paradoxically be beneficial, and after a heart attack, where an altered heart rate and blood pressure setpoint may be part of compensatory mechanisms to ensure the optimal function of a failing heart. While these altered values are potentially ‘outside’ of the ‘healthy’ setpoint level range, they may have utilitarian value and would be metabolically appropriate in relation to either a fever or failing heart. How the regulatory homeostatic control mechanisms ‘know’ that these altered metabolic setpoints are beneficial rather than harmful, and ‘accepts’ them as temporary or permanent new setpoints, or whether these altered values are associated with routine homeostatic corrective responses which are part of the body’s ongoing attempt to induce healing in the presence of fever or heart failure (amongst other homeostatically paradoxical examples), is still not clear. Whether homeostasis as a principle extends beyond merely controlling our body’s activity and behaviour, to more general societal or environmental control, is also still controversial. For example, James Lovelock, with his Gaia hypothesis, has suggested that the world in its entirety is regulated by homeostatic principles, and global temperature increases result in compensatory changes on the earth and in the atmosphere that lead to eventual cooling of the earth, and this warming and cooling continues in a cyclical manner – and most folk who believe in global warming as a contemporary unique catastrophic event don’t like this theory, even if it is difficult to support or refute without measuring temperature changes accurately over millennia.

Homeostatic control mechanisms can fail, and indeed our deaths are sometimes suggested to be the result of a failure of homeostasis. For example, cancer cells overwhelm cellular homeostatic protective mechanisms, or develop rapidly due to uncontrolled cellular proliferation of abnormal cells which are not inhibited by the regular cellular homeostatic negative feedback control mechanisms, which lead to physical damage to the body and ultimately our death, for these or other reasons that we are still not aware of. In contrast, Sigmund Freud, in his always contrary view of life, suggested as part of his Thanatos theory that death in the ultimate form of ‘rest’ and is our ‘baseline’ constancy-related resting state which we ‘go back to’ when dying (with suicide being a direct ‘mechanism’ of reaching this state in those whose psyche are operating too far away from their psychological setpoints, whatever these are), although again this is a difficult theory to either prove or disprove. Finally, what is challenging to a lot of folk about homeostasis from a control / regulatory perspective is that it is a conceptual ‘entity’ rather than a physical process that one can ‘show’ to be ‘real’, much like Plato’s Universals (to Plato the physical cow itself was less relevant than the ‘concept’ of a cow, and he suggested that one can only have ‘mere opinions’ of the former, while one has absolute knowledge of the latter, given the physical cow changes as it grows, ages, and dies, while the ‘concept’ of a cow is immutable and eternal). It is always difficult scientifically to provide categorical evidence which either refutes or support concepts such as universals and non-physical general control theories, even if they are concepts which appear to underpin all life as we know it, and without which function we could not exist in our current physical form and living environment.

As I look out the window at the falling autumn leaves and wonder whether we will have a very cold winter this year and whether we have prepared adequately for it clothes-wise (pre-emptive long-term homeostatic planning at its best, even if perhaps a bit ‘over-the-top’), while taking off my jersey as I write this given that the temperature has increased as the day has changed from morning to afternoon (surely a reactive homeostatic response), and as I ponder my health-related parameters, and work out how I am going to get those that need improvement as close to ‘normal’ as possible (surely as part of behavioural homeostatic / health-optimization planning), I look forward to that bike ride now I have managed to delay gratification of doing so until I have completed writing this (and feel a sense of well-being both from doing so and by realizing I am now ‘free’ to go on the ride and by doing so can remove the psychological ‘itch’ that makes me want to do it and therefore return to a state of psychological ‘constancy’ / homeostasis). Contemplating all of these, it is astonishing to think that all of what I, and pretty much all folk, do is underpinned by a desire to be, and maintain life, in a ‘comfort zone’ which feels right for me, and which is best for my bodily functions and psychological state. Given that all folk in the world have similar physical parameters when we measure them clinically, it is likely that our ‘comfort zones’ both physically and psychologically are not that different in the end. Perhaps the relative weighting which each of us assigns to our psychological or physical ‘needs’ create minor differences between us (and occasionally major differences such as in folk with psychopathology or with those who have significant lifestyle related physical disorders), though at the ‘heart of it all’, both psychologically and physically, is surely the over-arching principle of homeostasis. While on the bike this afternoon, I’ll ponder on the big questions related to homeostasis which still need to be answered, such as how homeostasis-related decisions are made, how the same principle can regulate not just our body, but also our behaviour, and perhaps that of societal and even planetary function, and how ‘universals’ originated and which came first, the physical entity or the universal. Sadly I think it will need a very long ride to solve these unanswered questions, and remove the ‘itch that needs scratching’ which arises from thinking of these concepts as a scientist who wants to solve them – and I don’t like to spend too long out of my comfort zone, which is multi-factorial and not purely bike-focused, but rather is part bike, part desk, part comfy chair, the latter of which will surely become more attractive after a few hours of cycling, and will ‘call me home’ to my next ‘comfort zone’, probably long before I can solve any of these complex issues while out on the ride watching the autumn leaves fall under a beautiful warm blue sky, with my winter cycling jacket unused but packed in my bike’s carrier bag in case of a change in the weather.

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Muscle Dysmorphia And The Adonis Complex – Mirror, Mirror On The Wall, Why Am I Not The Biggest Of Them All

I have noticed recently that my wonderful son Luke, who is in the pre-teenage years, has become more ‘aware’ of his body and discusses things like ‘six-pack abs’ and the need to be strong and have big muscles, probably like most boys of his age. I remember an old colleague at the University of Free State mention to me that her son, who was starting his last year at school, and who was a naturally good sports-person, had started supplementing his sport with gym work as he perceived that ‘all boys his age were interested in having big muscles’, as my colleague described it. A few decades ago, my old colleague and friend Mike Lambert, exercise physiologist and scientist without peer, and I did some work researching the effect of anabolic steroid use on bodybuilders, and noted that there were not just physical but also psychological changes in some of the trial participants. I did a fair amount of time in the gym in my University days, and always wondered why some of the biggest folk in the gym seemed to do their workouts with long pants and tracksuit tops, sometimes with hoods up, even on hot days, and how in conversation with them I was often told that despite them being enormous (muscular rather than obese-wise), they felt that they were small compared to their fellow bodybuilders and weightlifters, and that they needed to work harder and longer in the gym than they were currently doing to get results. All of these got me thinking of the fascinating syndrome known as muscle dysmorphia, also known as the Adonis complex, ‘bigorexia’, or ‘reverse anorexia’ and what causes the syndrome / disorder in the folk that develop it.

Muscle dysmorphia is a disorder mostly affecting males (though females can also be affected) where there is a belief or delusion that one’s body is too small, thin, insufficiently muscular or lean, despite it often being normal or exceptionally large and muscular, and related to obsessional efforts to increase muscularity and muscle mass by weightlifting exercise routines, dietary regimens and supplements, and often anabolic steroid use. This perception of being not muscular enough becomes severely distressing for the folk suffering from the syndrome, and the desire to enhance their muscularity eventually impacts negatively on the sufferer’s daily life, work and social interactions. The symptoms usually begin in early adulthood, and are most prevalent in body-builders, weight-lifters, and strength-based sports participants (up to 50 percent in some bodybuilder population studies, for example). Worryingly, muscle dysmorphia is increasingly being diagnosed in younger / adolescent folks, and across the spectrum of sports participants, and even in young folk who begin lifting weights for aesthetic rather than sport-specific purposes, and who from the start perceive they need to go to gym to improve their ‘body beautiful’. Two old academic friends of mine, Dave Tod and David Lavallee, published an excellent article on muscle dysmorphia a few years ago, where they suggested that the diagnostic criteria for the disorder are that the sufferer needs to be pre-occupied with the notion that their bodies are insufficiently lean and muscular, and that the preoccupation needs to cause distress or impairment in social or occupational function, including at least two of the four following criteria: 1) they give up / excuse themselves from social, occupational or recreational activities because of the need to maintain workout and diet schedules; 2) they avoid situations where their bodies may be exposed to others, or ‘endure’ such situations with distress or anxiety; 3) their concerns about their body cause distress or impairment in social, occupational or other areas of their daily functioning; and 4) they continue to exercise and monitor their diet excessively, or use physique-enhancing supplements or drugs such as anabolic steroids, despite knowledge of potential adverse physical or psychological consequences of these activities. Folk with muscle dysmorphia spend a lot of their time agonizing over their ‘situation’, even if it is in their mind rather than reality, look at their physiques in the mirror often, and are always of the feeling that they are smaller or weaker than what they really are, so there is clearly some cognitive dissonance / body image problem occurring in them.

What causes muscle dysmorphia is still not completely known, but what is telling is that it was first observed as a disorder in the late 1980’s and early 1990’s, and was first defined as such by Harrison Pope, Katharine Phillips, Roberto Olivardia and colleagues in a seminal publication of their work on it in 1997. There are no known reports of this disorder from earlier times, and as suggested by these academics, it’s increasing development appears to be related a growing social obsession with ‘maleness’ and muscularity, that is evident in the media and marketing adverts of and for the ‘ideal’ male in the last few decades. While women have had relentless pressure on them from the concept of increasing ‘thinness’ as the ‘ideal body’ perspective for perhaps a century or longer from a social media perspective, with for example the body size of female models and advertised clothes sizes decreasing over the years (and it has been suggested that in part this is responsible for the increase in the prevalence in anorexia nervosa in females), it appears that males are now under the same marketing / media ‘spotlight’, but more from a muscularity rather than a ‘thinness’ perspective, with magazines, newspapers and social media often ‘punting’ this muscular ‘body ideal’ for males when selling male-targeted health and beauty products. Some interesting changes have occurred which appear to support this concept, for example the physique of GI-Joe toys for young boys changing completely in the last few decades, apparently being much more muscular in the last decade or two compared to their 1970 prototypes. Matching this change, in 1972 only 15-20 percent of young men disliked their body image, while in 2000 approximately 50% percent of young men disliked their body image. Contemporary young men (though older men may also be becoming increasingly ‘caught up’ in similar desire for muscularity as contemporary culture puts a price on the ‘body beautiful’ right through the life cycle) perceive that they would like to have 13 kg more muscle mass on average, and believe that women would prefer them to have 14 kg more muscle mass to be most desirable, though interestingly when women were asked about this, women were happy with the current mass of their partners, and many were indeed not attracted to heavily-muscled males. Therefore, it appears that social pressure may play a large part in creating an environment where men perceive their bodies in a negative light, and this may in turn lead to the development of a ‘full blown’ muscle dysmorphia syndrome in some folk.

While the concept that social pressure plays a big role in the development of muscle dysmorphia, other factors have also been suggested to play a part. Muscle dysmorphia is suggested to be associated with, or indeed a sub-type of, the more general body dysmorphic disorder (and anorexia nervosa, though of course anorexia nervosa is about weight loss, rather than weight gain), where folk develop a pathological dislike of one or several body parts or components of their appearance, and develop a preoccupation with hiding or attempting to fix their perceived body flaw, often with cosmetic surgery (and this apparently affects up to 3 percent of the population). It has been suggested that both muscle dysmorphia and body dysmorphic disorder may be caused by a problem of ‘somatoperception’ (knowing one’s own body), which may be related to organic lesions or processing issues in the right parietal lobe of the brain, which is suggested to be the important area of the brain for own-body perception and the sense of self. In folk that have lesions of the right parietal cortex, they perceive themselves to be ‘outside’ of their body (autoscopy), or that body parts are missing / there is a lack of awareness of the existence of parts of the body (asomatognosia). Non-organic / psychological factors have also been associated with muscle dysmorphia, apart from media and socio-cultural influences, including being a victim of childhood bullying, being teased about levels of muscularity when young, or being exposed to violence in their family environment. It has also been suggested that it is associated with appearance-based rejection sensitivity, which is defined as anxiety-causing expectations of social rejection based on physical appearance – in other words, for some reason, folk with muscle dysmorphia are anxious that they will be socially rejected due to their perceived lack of muscularity and associated appearance deficits. Whether this rejection sensitivity is due to prior negative social interactions, or episodes of childhood teasing or body shaming, has not been well elicited. Interestingly, while studies have reported inconclusive correlations with body mass index, body fat, height, weight, and pubertal development age, there have been strong correlations reported with mood disorders, anxiety disorders, perfectionism, substance abuse, and eating and exercise-dependence / addiction disorders, as well as with the clinical depression, anxiety, and obsessive-compulsive disorders. There does not appear to be a strong relationship to narcissism, which perhaps is surprising. Whether these are co-morbidities or they have a common pathophysiology at either a psychological or organic level is yet to be determined. It has been suggested that a combination of cognitive behavioural therapy and selective serotonin reuptake inhibitor prescription (a type of antidepressant) may improve the symptoms of muscle dysmorphia. While these treatment modalities would support a link between muscle dysmorphia and the psychological disorders described above, the efficacy of these treatment choices is still controversial, and there is unfortunately a high relapse rate. It is unfortunately a difficult disorder to ‘cure’, given that all folk need to eat regularly in order to live, and most folk incorporate exercise into their daily routines, which make managing ‘enough’ but not ‘excessive’ amounts of weightlifting and dietary regulation difficult to regulate in folk who have a disordered body image.

Muscle dysmorphia appears therefore to be a growing issue in contemporary society, which is increasing in tandem with the increased media-related marketing drive for the male ‘body beautiful’, which now appears to be operating at a similar level to the ‘drive for thinness’ media marketing which has blighted the female perception of body image for a long time, and has potentially led to an increased incidence of body image disorders such as anorexia nervosa and body dysmorphic syndrome. However none of these are gender specific, and it is not clear how much of a relationship these body image disorders have with either organic brain or clinical psychological disorders, as described above. It appears to be a problem mostly in young folk, with older folk being more accepting of their body abnormalities and imperfections, whether these are perceived or real, though sadly it appears that there is a growing incidence of muscle dysmorphia and other body image disorder in older age, as societies relationship and expectations of ‘old age’ changes. As I see my son become more ‘interested’ in his own physique and physical development, which must have obviously been caused by either discussions with his friends, or due to what he reads, or what the ‘actors’ in his computer games look like which he so enjoys playing, like all his friends, I hope he (and likewise my daughter) will always enjoy his sport but have a healthy self-image through the testing teenage and early adult period of time. I remember those bodybuilders my colleague Mike and I worked with all those years ago, and how some of them were comfortable with their large physiques, while with some it was clearly an ordeal to take off their shirts in order to be tested in the lab as part of the trials we did back then. The mind is very sensitive to suggestion, and it is fascinating to see that males now are being ‘barraged’ with advertising suggesting they are not good enough, and if they buy a certain product it will make them stronger, fitter, better, and thus more attractive, to perhaps the same level females have been subjected to for a long period of time. The mind is also sensitive to bullying, teasing and body shaming, as well as a host of other social issues which impinge on it particularly in its childhood and early adolescent development phases. It’s difficult to know where this issue will ‘end’, and whether governmental organizations will ‘crack down’ on such marketing and media hype which surely ‘target’ folks (usually perceived) physical inadequacies or desires, or if it is too late to do so and such media activity has become innate and part of the intrinsic fabric of our daily life and social experience. Perhaps education programs are the way to go at school level, though these are unfortunately often not successful.

There are so many daily challenges one has to deal with, it may seem almost bizarre that folk can spend time worrying about issues that are not even potentially ‘real’, but for the folk staring obsessively at themselves in the mirror, or struggling to stop the intrusive thoughts about their perceived physical shortcomings, these challenges are surely very real, and surely all-consuming and often overwhelming. In Greek mythology Adonis was a well-muscled half man, half god, whose was considered to be the ultimate in masculine beauty, and according to mythology his masculine beauty was so great that he won the love of Aphrodite, the queen of all the gods, because of it. Sadly for the folk with muscle dysmorphia, while they may be chasing this ideal, they are likely to be too busy working on creating their own perfect physique to have time to ‘woo’ their own Aphrodite, and indeed, contemporary Aphrodite’s don’t appear to even appreciate the level of muscularity they eventually obtain. The mirror on the wall, as it usually is, is a false siren, beckoning those weak enough to fall into its thrall – no matter how big, never to appear as the biggest or most beautiful of all.


Consistency Of Task Outcome And The Degrees Of Freedom Problem-The Brain Is Potentially Not A Micro-Manager When Providing Solutions To Complex Problems

Part of the reason I enjoy cycling as my chosen sport now I am older is not just because it is beneficial from a health perspective, but because the apparent regularity of the rhythmical circular movement required for pedalling creates a sense of peace in me and paradoxically allows my mind to wander a bit away from its routine and usually work-focussed and life task orientated thoughts. I enjoy watching competitive darts, from the perspective of marvelling at how the folk participating in the competitions seem to so often hit the small area of the board they are aiming for with such precision, after fairly rapidly throwing their darts when it is their turn to do so. This week an old colleague and friend from University of Cape Town days, Dr Angus Hunter, published some interesting work on how the brain controls muscle activity during different experimental conditions, a field of which he is a world expert in, and it was great to read about his new research and innovative ideas as always. Some of the most fun times of my research career were spent in the laboratory working with Angus measuring muscle activity during movement related tasks, where one of our most challenging issues to deal with was the variability of the signal our testing devices recorded when measuring either the power output from, or electrical activity in, muscle fibres each time they contracted when a trial participant was asked to do the same task. A large part of the issue we had to solve then was whether this was signal ‘noise’ and an artefact of our testing procedures, or if it was part of the actual recruitment strategy the brain used to control the power output from the muscles. All of these got me thinking about motor control mechanisms, and how movement and activity is regulated in a way that gets tasks done in a seemingly smooth and co-ordinated way, often without us having to think about what we are doing, while when one measures individual muscle function it is actually very ‘noisy’ and variable, even during tasks which are performed with a high degree of accuracy, and how the brain either creates or ‘manages’ this variability and ‘noise’ to generate smooth and accurate rhythmical or target-focussed activity, as that which occurs when cycling and throwing darts respectively.

Some of the most interesting scientific work that I have ever read about was done by Nikolai Bernstein, a Russian neurophysiologist, who when working in the 1920’s at the somewhat euphemistically named Moscow Central Institute of Labour, examined motor control mechanisms during movement. As part of the communist government of the times centrally driven plans to improve worker productivity and output, Bernstein did research on manual labour tasks such as hammering and cutting, in order to try and understand how to optimise it. Using novel ‘cyclogram’ photography techniques, where multiple pictures were taken of a worker using a hammer or chisel to which a light source had been attached, he was able to produce the astonishing observation that each time the worker hit a nail or cut through metal, their arm movements were not identical each time they performed the action, and rather that there was a great degree of variability each time the similar action was performed, even though usually this variability in action produced an outcome which had a high degree of accuracy. He realized that each complete movement, such as moving the arm towards the target, is made up of a number of smaller movements of muscles around the shoulder, elbow and wrist joints, which together synergistically create the overall movement. Given how many muscles there are in the arm, working around three joints (and potentially more when one thinks of the finger joints and muscles controlling them), he suggested that were a very large number of potential combinations of muscle actions and joint positions that could be used for the same required action, and a different combination of these appeared to be ‘chosen’ by the brain each time it performed a repetitive task. From a motor control perspective, Bernstein deduced that this could potentially cause a problem for the brain, and whatever decision-making process decided on which movement pattern it would use to complete a task, given that it created a requirement for choosing a particular set of muscle synergies from a huge number of different options available, or in contrast not choosing all the other muscle synergistic options, each time the individual was required to perform a single task or continue performing a repetitive task. This would require a great amount of calculation and decision-making capacity on a repetitive basis by the brain / control processes, and he called this the motor redundancy, or degrees of freedom, problem.

Like a lot of work performed in the Stalin era in Russia, his fascinating work and observations did not become known to Western scientists until the 1960’s, when he published a text-book of his career in science, which was subsequently translated and taken forward by excellent contemporary movement control scientists like Mark Latash of the University of Pennsylvania State in the USA. Further studies have supported Bernstein’s earlier work, and it is astonishing how much variability there is in each movement trajectory of a complex action that is goal orientated. Mark has suggested that this is not a redundancy problem, but rather one of abundancy, with the multiple choices available being of benefit to the body of any individual performing repetitive tasks, potentially from a fatigue resistance and injury prevention perspective, which may occur if the same muscle fibres in the same muscle are used in the same way in a repetitive manner. Interestingly, when a person suffers a stroke or a traumatic limb injury, the quantity of movement variability appears to paradoxically reduce rather than increase after the stroke or injury, and this reduced variability of motor function is associated with a decrement in task performance accuracy and completion. Therefore, the high variability of movement patterns in healthy folk appears to paradoxically make task performance more accurate and not just more efficient.

How control processes choose a specific ‘pattern’ of muscle activity for a specific task is still not well known. A number of theories have been proposed (generally as a rule in science, the more theories there are about something, the more the likelihood there is that there is no clarity about it) with some quaint names, such as the equilibrium point hypothesis, which suggests that choice at the motor neuron level is controlled as part of the force-length relationship of the muscle; the uncontrolled manifold hypothesis, which suggests that the central nervous system focuses on the variables needed to control a task and ignores the rest (the uncontrolled manifold being those variables that do not affect task required activity); and the force control hypothesis, which suggests that the central nervous systems compares the required movement for the task against internal models, and then uses calculations and feedforward and feedback control mechanisms to direct activity against that set by the internal model; amongst others. All these are interesting and intellectually rigorous theories, but don’t tell us very much about exactly how the brain chooses a particular group of muscles to perform a task, and then subsequently a different group of muscles, which use a different flight trajectory, to perform the task again when it is repeated. It has been suggested that there are ‘synergistic sets’ of muscles which are chosen in their entirety for a single movement, and that the primitive reflexes or central pattern generators in the spinal cord may be involved. But the bottom line is that we just do not currently know exactly what control mechanism chooses a specific set of muscles to perform one movement of a repetitive task, why different muscles are chosen each time the same task is performed sequentially, or how this variable use of muscles for the same task is managed and controlled.

We have previously suggested that a number of other activities in the body beyond that of muscle control have similar redundancy (or abundancy) in how they are regulated, or at least in respect of which mechanisms are used to control them. For example, blood glucose concentrations can be controlled not only by changes in insulin concentrations, but also by that of glucagon, and can also be altered by changes in catecholamine (adrenaline or noradrenaline) or cortisol levels, and indeed by behavioural factors such as resisting the urge to eat. Each time blood glucose concentrations are measured, the concentrations of all these other regulatory hormones and chemicals will be different ratio-wise to each other, yet their particular synergistic levels at any one point in time maintains the level of blood glucose concentrations at homeostatically safe setpoint levels. The blood glucose level is maintained whatever the variability in the regulatory factor concentration ratios, and even though this variability in choice of control mechanisms similarly creates a potential for high computational load when managing blood glucose concentrations from a control perspective. Similarly, perception of mood state or emotions are thought to have redundancy in what factors ‘creates’ them. For example we can fairly accurately rate when we feel slightly, moderately or very fatigued, but underpinning the ‘feeling’ of fatigue at the physiological level can be changes in blood glucose, heart rate, ventilation rate, and a host of other metabolites and substrates in the body, each of which can be altered in a variable ratio way to make up the sensation of fatigue we rate as slightly, moderately or very high levels of fatigue. Furthermore, fatigue is a complex sensation made up of individual sensations such as breathlessness, pounding chest, sweating, pain, and occasionally confusion, dizziness, headache and pins and needles, amongst others, a combination of which can also be differently valenced to provide a similar general fatigue rating by whoever is perceiving the sensation of fatigue. To make it even more complex, the sensation of fatigue is related to inner voices which either rate the sensation of fatigue (the ‘I’ voice) or make a judgement on it related to social circumstances or family and environmental background (the ‘Me’ voice), and it is through the final combination of these that an individual finally rates their level of fatigue, which adds another level of redundancy, or abundancy, to the factors underpinning how the ‘gestalt’ sensation of fatigue is both created and perceived. There are therefore three potential ‘levels’ of redundancy / abundancy in the signals and factors which either individually or collectively make up the ‘gestalt’ sensation of fatigue, and a corresponding increased level of computational requirements potentially associated with its final genesis, and how this perceptual redundancy / abundancy is managed by the control mechanisms which generate them is still not well known.

In summary, therefore, the presence of variability during activities of daily living across a number of different body systems is not only ‘noise’ / artefacts of testing conditions which are challenges for us researchers to have to deal with, it also appears to be part of some very complex control mechanisms which must have some teleological benefit both for optimizing movement and activity, and ensuring the capacity to sustain it without fatigue or injury to the components of the mechanism which produces it. Each time I cycle on my bike and my legs move up and down to push the wheels forward, different muscles are being used in a different way during each rotation of the wheel. Each time a darts player throws a dart, different muscle synergies are used to paradoxically create the accuracy of their throw. There is real ‘noise’ that a researcher has to remove from their recorded traces after a testing session in a laboratory, such as that caused by the study participant sweating during the trial, which can affect electrophysiological signals, and there is always a degree of measurement error, and therefore some degree of ‘noise’ is present in the variability of the recorded output for any laboratory technique that measures human function. But, equally, Bernstein’s brilliant work and observations all those years ago helped us understand that variability is inherent in living systems, and after understanding this, each time I observe data, particularly that generated during electrophysiological work such as I have used for a number of experiments in my own research career, including electromyography (EMG), electroencephalography (EEG) or transcranial magnetic stimulation (TMS), which has low standard deviations in the results sections of published research articles, I do wonder at the validity of the data and whether it has been ‘paintbrushed’ by the researchers who describe it, as my old Russian neurophysiology research colleague Mikhail Lomarev used to describe it, when he or we thought data was ‘suspect’. The inherent variability in brain and motor control systems makes finding statistical significance in results generated using routine neurophysiological techniques more difficult. It also seems to create a huge increase in the requisite control-related calculations and planning for even a simple movement, though as Mark Latash suggested, the brain is likely to not be a micro-manager, but rather some effective parsing mechanism which can both generate and utilize a large number of synergistic movement patterns in a variable manner for any task, while not utilizing much decision making power using some sort of heuristic-based decision-making mechanism. Most importantly though, it fills one with a sense of awe at the ‘magic’ of our own body, and for the level of complexity involved in both its creation and operative management, when even a simple movement like striking an object with a hammer, or cutting a piece of metal, can be underpinned by such complex control mechanisms that our brains cannot currently comprehend or make sense of.

In a laboratory in the middle of Russia nearly a century ago, Nikolai Bernstein made some astonishing observations by doing exceptional research on basic motor control, while trying to increase the productivity of soviet-era industrial work. A century later we are still scratching our heads trying to understand what his findings mean from a motor control perspective. As I type these final sentences, I reflect on this, and wonder which synergistic composition of muscle activity in my fingers are responsible for creating the actions which lead to these words being generated, and realize that each time I do so, because of the concepts of variability, redundancy and abundancy, I will probably never use an identical muscle sequence when typing other ideas into words at another future point in time. But then again, I guess the words I will be writing in the future will also be different, and daily life, like motor control programs, will always vary, always change, even though the nail on the wall on which the picture hangs becomes a permanent ‘item’, as will this article become permanent when I hit the ‘send’ button to publish it. What is never to be seen again though are the traces in the ‘ether’ of the hammer blow which embedded the nail in the wall, and the exact movement of the individual muscles in the labourers arms and hands, and in my fingers as I typed which created these words. Like magic their variability was created, and like magic their pattern has dispersed, never to recur again in the same way or place, unless some brilliant modern day Bernstein can solve their magic and mystery, reproduce them in their original form using some as yet to be invented laboratory device, and publish them in a monograph. Let’s hope that if they do so, their great work does not languish unseen for forty years before being discovered by the rest of the world’s scientists, as was Bernstein’s wonderful observations of all those years ago!


The Core Requirement And Skill Of Decision-Making In Life – Removal Of Uncertainty Is Usually Positive And Cathartic But Is Also An Ephemeral Thing

This week, for the first time since moving to New Zealand and starting a new job here, I cycled in to work, and in the early afternoon faced a tough decision regarding whether I had the level of fitness capacity to cycle back home at the end of the day. Three-quarters of the way through the ride home, I felt very tired and stopped by the side of the road, and considered phoning home and asking them to pick me up. This morning I opened the fridge and had to decide whether to have the routine fruit and yogurt breakfast or the leftover piece of sausage roll. We have been six months in our new life and job here, and we have come to that period of time of deciding whether we have made a good decision and to continue, or whether we have made a disastrous error and need to make a rapid change. As I write this my wife asks me if I planned to go to the shop later, and if so whether I could get some milk for the family, and I had to stop writing and decide on whether I was indeed going to do so as part of the weekend post-writing chores, or not. All of these activities and issues required me to make decisions, and while some of them appeared to be of little consequence, some of them were potentially life and career changing, and, even if it seems a bit dramatic, potentially life-ending (whether to continue cycling when exhausted as a fifty-something). Decisions like these have to be made by everyone on a minute by minute basis as part of their routine daily life. The importance of decision-making in our daily lives, and how we make decisions, is still controversial and not well understood, which is surprising, given how much our optimal living condition and indeed survival depends on making correct decisions, and how often we have to make decisions, some of which are simple, some of which appear simple but are complex, and some of which are overtly complex.

Decision-making is defined as the cognitive process (which is the act or process of knowing or perceiving) resulting in the selection of a particular belief or course of action from several alternative possibilities, or as a problem-solving activity terminated by the genesis or arrival of a solution deemed to be satisfactory. At the heart of any decision-making is the requirement to choose between an array of different options, all of which usually have both positive and negative potential attributes and consequences, where one uses prior experience or a system of logical ‘steps’ to make the decision based on forecasting and scenario-setting for each possible alternative choice and consequence of choosing them. One of the best theoretical research articles on decision-making I have read / been involved with is one written by Dr Andy Renfree, an old colleague from the University of Worcester, and one of the Sport Science academic world’s most creative thinkers. As a systems level, he suggested that decisions are made based on either rational or heuristic principles, the former working best in ‘small world’ environments (in which the individual making the decision has absolute knowledge of all decision-related alternatives, consequences and probabilities), and the latter best in ‘large world’ environments (in which some relevant information is unknown or estimated). As described by Andy, rational decision-making is based on the principle that decisions can only be made if certain criteria are met, namely that the individuals making the decision must be faced with a set of behavioral alternatives and, importantly, information must be available for all possible alternatives of decisions that can be made, as well as of the statistical probability of all of the outcomes of the choices that can be made. This is obviously a large amount of requisite information, and a substantial period of time would be required to make a decision based on such ‘rational’ requirements. While using this method would likely be the most beneficial from a correct outcome perspective, it would also potentially place a high demand on the cognitive processes of the individual making the decision. Bayesian decision-making is a branch of rational decision-making theory, and suggests that decision-making is the result of unconscious probabilistic inferences. In Bayesian theory, a statistical approach to decision-making is made based on prior experience, with decision making valenced (and therefore speeded up) by applying a ‘bias’ towards information that is used to make the decision which is believed to be more ‘reliable’ than other information, and ‘probability’ of outcomes being better or worse based on prior experience. Therefore, in the Bayesian model, prior experience ‘speeds up’ decision making, though all information is still processed in this model.

In contrast, heuristic decision-making is a strategic method of making decisions, which ignores information that is available but is perceived to be less relevant to the specific decision being made, and which suggests that decisions are made based on key information and variables that are assessed and acted upon rapidly, in a manner that, as Andy suggests, incorporates ‘rule of thumb’ or ‘gut feel’ thinking, which places less demands on the cognitive thinking processes of the individual. As described above, rational decision-making may be more relevant in ‘small world’ environments, in which there are usually not a lot of variables or complexity which are required to be assessed prior to making a decision, and heuristic thinking in ‘large world’ environments, which are complex environments where all information, whether relevant or not, cannot be known, due to the presence not only of ‘known unknowns’ but also ‘unknown unknowns’, and where an individual would be potentially immobilized into a state of ‘cognitive paralysis’ if attempting to assess every option available. The problem or course is that even decisions that appear simple often have multiple layers of complexity that are not overt and of which the individual thinking about them is not aware, and it can be suggested that the concept of both rational and ‘small world’ environments are potentially abstract principles rather than reality, that all life occurs as part of ‘large world’ environments, and that heuristic processes are what are used by individuals as the main decision-making principles during all activities of daily living.

Of course, most folk would perceive that these rational and heuristic models are very computational and mathematical based, and that perhaps ‘feelings’ and ‘desires’ are also a component of decision-making, or at least these are how decision-making is perceived to ‘feel’ to them. As part of the Somatic Marker hypothesis, Antonio Damasio suggested that ‘body-loop’ associated emotional processes ‘guide’ (and have the potential to bias) decision-making behavior. In his theory, somatic markers are a specific ‘group of feelings’ in the body and are associated with specific emotions one perceives when confronted with, and are related to, the facts or choices one is faced with and need to make a decision about. There is suggested to be a different somatic marker for anxiety, enjoyment, or disgust, among other emotions, based on an aggregation of body-related symptoms for each, such as heart rate changes and the associated feeling of a pounding chest, the sensation of breathing changes, changes in body temperature, increased sweat rate, or the symptom of nausea, some or all of which together are part of a certain somatic marker group which creates the ‘feeling’ of a particular emotion. Each of these physiologically based body-loop ‘states’ are capable of being components of different somatic marker ‘groups’, which create the distinct ‘feelings’ which are associated with different emotions, and which would valence decisions differently depending on which somatic marker state / emotion is created by thinking of a specific option or choice. This hypothesis is based on earlier work by William James and colleagues more than a hundred years ago, which became the James-Lange theory of emotion, which suggests there is a ‘body-loop’ required for the ‘feeling’ of emotions in response to some external challenge, which is in turn required for decision-making processes related to the external challenge. The example used to explain this theory was that when one sees a snake, it creates a ‘body loop’ of raised heart rate, increased sweating, increased breath rate and the symptom of nausea, all of which in turn create the ‘feeling’ of fear once these ‘body-loop’ symptoms are perceived by the brain, and it was hypothesized that it is these body-generated feelings, rather than the sight of the snake itself, which induces both the feeling of fear and the decision to either rapidly run away or freeze and hope the snake moves away. While this model is contentious as it would make reactions occur slower than if a direct cognitive decision-making loop occurred, it does explain the concept of a ‘gut feel’ when decision-making. Related to this ‘body-loop’ theory, are other behavioral theories about decision-making, and it has been suggested that decisions are based on what the needs, preferences and values of an individual are, such as hunger, lust, thirst, fear, or moral viewpoint, but of course all of these could equally be described as components of either a rational or heuristic model, and psychological / emotional and cognitive / mathematical models of decision-making are surely not mutually exclusive conditions or theories.

These theories described above attempt to explain how and why we make decisions, but not what causes decisions to be right or wrong. Indeed, perhaps the most relevant issue to most folk is why they so often get decisions wrong. A simple reason may be that of ‘decision fatigue’, whereby the quality of decision-making deteriorates after a prolonged period of decision-making. In other words, one may simply ‘run out’ of the mental energy which is required to make sound decisions, perhaps due to ongoing changes in ‘somatic markers’ / body symptoms each time a decision is required to be made, which creates an energy cost that eventually ‘uses up’ mental energy (whatever mental energy is) over the period of time sequential decisions are required to be made. Astonishingly, judges working in court have been shown to make less favorable decisions as a court session progresses, and the number of favorable decisions improves after the judges have had a break. Apart from these data suggesting that one should ask for a court appearance early on in the morning or after a break, it also suggests that either physical or mental energy in these judges is finite, and ‘runs out’ with prolonged effort and the use of energy focusing on decision-making related to each case over the time period of a court session. There are other more subtle potential causes of poor-decision making. For example, confirmation bias occurs when folk selectively search for evidence that supports a certain decision that they ‘want’ to make, based on an inherent cognitive bias set in their mind by past events or upbringing, even if their ‘gut’ is telling them that it is the wrong decision. Cognitive inertia occurs when folk are unwilling to change their existing environment or thought patterns even when new evidence or circumstances suggest they should. People tend to remember more recent information and use it preferentially, or forget older information, even if the older information is potentially more valid. Repetition bias is caused by folk making decisions based on what they have been told, if it has been told to them by the greatest number of different people, and ‘groupthink’ is when peer pressure to conform to an opinion or group action causes the individual to make decisions they would not do if they were alone and not in the group. An ‘illusion of control’ in decision-making occurs where people have a tendency to under-estimate uncertainty because of a belief that they have more control over events that they actually have. While folk with anxiety tend to make either very conservative or paradoxically very rash decisions, sociopaths, who are thought to have little or no emotional ‘body-loop’, are very poor at making moral based decisions or judgments. Therefore, there are a whole lot of different factors which can impact negatively on decision-making, either due to one’s upbringing or prior history impacting on the historical memory which is used to valence decisions, or due to one’s current emotional or psychological state having a negative impact on decision-making capacity, and even simple fatigue can be the root cause of poor decision-making.

At the heart of decision-making (excusing the pun, from the perspective of the somatic marker hypothesis), is a desire of most folk to remove uncertainty from their lives, or change their life or situation to a better state or place as a result of their decision, or to remove a stressor from their life that will continue unless they make a decision on how to resolve it, remove it, or remove themselves from whatever causes the stressor. However, during my days as a researcher at the University of Cape Town, we suggested that conditions of uncertainty and certainty associated with information processing and decision-making are cyclical (we called it the ‘quantal packet’ information processing theory, for those interested). A chosen decision will change a position or state of uncertainty to one of certainty as one enacts changes based on the decision (or if one chooses to ‘wait and see’ and not alter anything) from the context that one is certain a change will occur based on what one has decided to do, even if one cannot be sure if this difference will be positive or negative while the changes are being enacted. However, with the passing of time, the effects of the decision made will attenuate, and uncertainty will eventually re-occur which require a further decision to be made, often with similar choices to which occurred when the initial decision was made. Underpinning this attenuation of the period of ‘certainty’ is the concept that although one will have factored in ‘known unknowns’ into any decision one makes using either rational or heuristic principles, ‘unknown unknowns’ will surely always occur that will cause even the best strategic decisions to require tactical adjustments, and those that are proven to be an error will need to be reviewed and changed. One can also ‘over-think’ decision-making as much as one can ‘under-think’ it, as well as being kept ‘hostage’ to cognitive biases from one’s past which continuously ‘trip one up’ when making decisions, despite one’s best intentions. Having said all of this, it often astonishes me not that folk get decisions wrong, but rather that they get so many decisions right. For example, when driving along a highway, one is reliant on the correct decisions of every driver that passes for one’s survival, from how much they choose to turn their steering wheel, to how much they use their brake for a corner, to an awareness in each of them that they are not too tired to be driving in the first place. It’s amazing when one thinks of how many decisions we make, either consciously or unconsciously, which so often turn out right, but equally it is the responsibility of each of us to work on the errors created by our past, or by our emotional state, or by ‘groupthink’, which we need to be vigilant about and remove as best possible from the psyche.

Making a decision is usually cathartic due to the removal of uncertainty and the associated anxiety which uncertainty often causes, even if the certainty and feeling of goodwill generated by making a decision is usually ephemeral and lasts only for a short period of time before other matters occupy one’s attention which require further decision-making. Pondering on my decision-making of the last week retrospectively, I think I made the right decision when choosing to cycle home after work, and to do so all the way home, even if I was exhausted when I got there, given that I did not collapse or have a heart attack when doing so, and there will surely be long term health benefits from two long cycles (though of course long is relative at my age!) in one day. I did choose the healthy food alternative for breakfast this morning, even though often I don’t, particularly during meals when I am tired after a long day’s work. I will get the milk my wife asked me to get this afternoon, in order to both get some fresh air after a creative morning of thinking and writing, and to maintain the harmony in our house and life, even though it is raining hard and I would prefer to be writing more or reading a good book this afternoon. The ‘jury is still out’ about whether this move to New Zealand and a new work role has been a good career and country move, and my current decision on this is to let more time pass before making an action-generating reasoned decision on it, though of course we have already moved several times to new places round the world in the last two decades, and the family is looking forward to some lifestyle stability in the next few years, and these factors need to be part of any reflection on a current-environment rating decision. Each of these decisions seemed ostensibly relatively simple to make when I made them, yet each surely had an associated entire host of different reasons, experiences, memories and requirements which were worked through in and by my mind before making them, as will be so for all folk making decisions on all aspects of their life during a routine day. What will I have for lunch now I am finished writing this and am now tired and in need of a break and sustenance? Perhaps I will leave off that decision and relax for a period of time before making lunch-related choices, so as not to make a fatigue-induced bad decision, and reach for that sausage roll, which still is in the fridge. And I need to get going and enact that decision I made to get the milk, and head off to the shops in order to do so as soon as possible, before lethargy set in and I change my mind, otherwise I will surely be in the ‘dog box’ at home later this afternoon, and my sense of cathartic peace resulting from having made these decisions will be even more ephemeral than usual!


Testosterone And Its Androgenic Anabolic Derivatives – One Small Drop Of Liquid Hormone That Can A Man Make And Can A Man Break

I watched a great FA Cup football final last night, and was amused as always when players confronted each other after tackles with aggressive postures and pouting anger-filled stares – all occurring in front of a huge crowd looking on and under the eyes of the referee to protect them. On Twitter yesterday and this morning I was engaged in a fun scientific debate with some male colleagues and noted that each time the arguments became ‘ad hominem’ the protagonists became aggressive and challenging in their responses, and only calmed down and became civil again when they realized it is banter. I have over many years watched my wonderful son grow up daily, and now he is ten have observed some changes occurring in him that are related to increasing development of ‘maleness’ which occurs in all young men of his age. In my twenties while completing my medical and PhD training, I worked part time as a bouncer, and it was always fascinating to see the behaviour of males in the bars and clubs I worked in then change when around females ‘dressed to kill’ and out for the evening. With the addition of alcohol this became a dangerous ‘cocktail’ late in the evenings, with often violence breaking out as the young men tried to establish their dominance and ‘turf’, or as a result of perceived negative slights which ‘honour’ demanded they respond to, and which resulted in a lot of work for me in the bouncer role to sort out. All this got me thinking of the male hormone testosterone and its effect on males through their lifetime, both good and bad.

Testosterone is the principal male sex hormone that ‘creates’ the male body and mind from the genetic chromosomal template supplied at conception. It is mostly secreted by the testicles in men, and to a lesser degree from the ovaries in women, with some secretion also from the adrenal glands. There is approximately 7-8 times higher concentration of testosterone in males than females, but it is present also in females, and females are susceptible to (and may even be more sensitive to) its actions. Testosterone is a steroid type hormone, derived originally from cholesterol related chemical substances which are turned into testosterone through a complex pathway of intermediate substances. Its output from the testes (or ovaries) is stimulated by a complex cascade of neuro-hormonal signals that arise from brain structures (gonadotrophin release hormone is released by the hypothalamus structure in the brain and travels to the pituitary gland, which in turn releases luteinizing hormone and follicle stimulating hormone, which travels in the blood to the testicles and in turn cause the release of testosterone into the bloodstream) in response to a variety of external and internal stimuli (though what controls testosterone’s release, and how it is controlled, in this cyclical manner over many years is almost completely unknown). The nature of ‘maleness’ has been debated as a concept since antiquity, but it was in the 1800’s that real breakthroughs in the understanding that there was a biological basis to ‘maleness’ occurred, with hormones being identified as chemical substances in the blood, and several scientist folk such as Charles Brown-Sequard doing astonishing things like crushing up testicles and injecting the resultant product into their own bodies to demonstrate the ‘rejuvenating’ effect of the ‘male elixir’. Eventually in the late 1800’s testosterone was isolated as the male hormone – it was named as a conglomerate derivative of the words testicle, sterol and ketone – and in the 1930’s, the ‘golden age’ of steroid chemistry, its structure was identified, and synthetic versions of testosterone were produced as medical treatment analogues for folk suffering from low testosterone production due to hypogonadism (reduced production of testosterone due to testicular function abnormality) or hypogonadotropism (reduced production of testosterone due to dysfunction of the ‘higher’ level testosterone release control pathways in the brain described above).

Testosterone acts in both an anabolic (muscle and other body tissue building) and androgenic (male sex characteristic development) manner, and one of the most fascinating things about it is that it acts in a ‘pulsatile’ manner during life – increasing dramatically at very specific times in a person’s life to effect changes that are absolutely essential for both the development and maintenance of ‘maleness’. For example, in the first few weeks after conception in males there is a spike in testosterone concentration in the foetus that results in the development of genitals and prostate gland. Again, in the first few weeks after birth testosterone concentrations rise dramatically, before attenuating in childhood, after which a further increase in the pre-puberty and the pubertal phases occurs, when it is responsible for increases in muscle and bone mass, the appearance of pubic and axillary hair, adult-type body odour and oily skin, increased facial hair, deepening of the voice, and all of the other features associated with (but not all exclusive to) ‘maleness’. If one of these phases are ‘missed’, normal male development does not occur. As males age, the effects of continuously raised testosterone associated with adulthood become evident as loss of scalp hair (male pattern baldness) and increased body hair, amongst other changes. From around the age of 55 testosterone levels decrease significantly, and remain low in old age. Raised testosterone levels have been related to a number of clinical conditions that in the past have been higher in males than females, such as heart attacks, strokes and lipid profile abnormalities, along with increased risk of prostate (of course it’s not surprising that this is a male specific disorder) and other cancers, although not all studies support these findings, and the differences in the gender-specific risk of cardiovascular disorders in particular is decreasing as society has ‘equalized’ and women’s work and social lives have become more similar to those of males in comparison to the more patriarchal societies of the past.

More interesting than the perhaps ‘obvious’ physical effects are the psychological effects of testosterone on ‘male type’ behaviour, though of course the ‘borders’ between what is male or female type behaviour are difficult to clearly delineate. Across most species testosterone levels have been shown to be strongly correlated with sexual arousal, and in animal studies when an ‘in heat’ female is introduced to a group of males, their testosterone levels and sex ‘drive’ increases dramatically. Testosterone has also been correlated with ‘dominance’ behaviour. One of the most interesting studies I have ever read about was one where the effect of testosterone on monkey troop behaviour was examined, in which there are strict social hierarchies, with a dominant male who leads the troop, submissive males who do not challenge the male, and females which are ‘serviced’ only by the dominant male and do not challenge his authority. When synthetic testosterone was injected into the males, it was found that the dominant male become increasingly ‘dominant’ and aggressive, and showed ‘challenge’ behaviour (standing tall with taught muscles in a ‘fight’ posture, angry facial expressions, and angry calls, amongst others) more often than usual, but in contrast, there was no effect or change of the testosterone injections on non-dominant male monkeys. When the females were injected with testosterone, most of them became aggressive, and challenged the dominant male and fought with him. In some cases the females beat the dominant male in fighting challenges, and became the leader of the troop. Most interestingly, these ‘became dominant’ females, when the testosterone injections were discontinued, did not revert back to their prior submissive status, but remained the troop leader and maintained their dominant behaviour even with ‘usual’ female levels of testosterone. This fascinating study showed that there is not only a biological effect of testosterone in social dominance and hierarchy structures, but that there is also ‘learned’ behaviour, and when one’s role in society is established, it is not challenged whatever the testosterone level.

Raised testosterone levels have also been linked with level of aggression, alcoholism, and criminality (being higher in all of these conditions) though this is controversial, and not all studies support these links, and it is not clear from the ‘chicken and egg’ perspective if increased aggression and antisocial behaviour is a cause of increased testosterone levels, or is a result of it. It is also been found that athletes have higher levels of testosterone (both males and females) during sport participation, as have folk watching sporting events. In contrast, both being ‘in love’ and fatherhood appears to decrease levels of testosterone in males, and this may be a ‘protective’ mechanism to attenuate the chance of a male ‘turning against’ or being aggressive towards their own partners or children. Whether this is true or not requires further work, but clearly there is a large psychological and sociological component to both the functionality and requirements of testosterone, beyond its biological effects. One of the most interesting research projects I have been involved with was at the University of Cape Town in the 1990’s, where along with Professor Mike Lambert and Mike Hislop, we studied the effect of testosterone ingestion (and reduction of testosterone / medical castration) on male and female study participants. We found not only changes in muscle size and mass in those taking testosterone supplements, but also that participants ingesting or injecting testosterone had to control their aggression levels and be ‘careful’ of their behaviour in social situations, while women participants described that their sex drive increased dramatically when ingesting synthetic testosterone. In contrast, men who were medically castrated described that their libido was decreased during the study time period when their testosterone levels were reduced by testosterone antagonist drugs to very low levels (interestingly they only realized this ‘absence’ of libido after being asked about it). All these study results confirm that testosterone concentration changes induce both psychological and social outcomes and not just physical effects.

Given in particular its anabolic effects, testosterone and its synthetic chemical derivatives, known commonly as anabolic steroids, became attractive as a performance enhancing drug by athletes in the late 1950’s and 1960’s as a result of it being massed produced synthetically from the 1930’s, and as athletes became aware of its muscle and therefore strength building capacity after its use in clinical populations. Until the 1980’s, when testing for it as a banned substance meant it became risky to use it, anabolic steroids were used by a large number of athletes, particularly in the strength and speed based sporting disciplines. Most folk over 40 years old will remember Ben Johnson, the 1988 Olympic 100m sprint champion, being stripped of his winner’s medal for testing positive for an anabolic steroid hormone during a routine within-competition drug test. Testosterone is still routinely used by body-builders, and worryingly, a growing number of school level athletes are being suggested to be using anabolic steroids, as well as a growth of its use as a ‘designer drug’ in gyms to increase muscle mass in those that have body image concerns. An interesting study / article pointed out that boy’s toys have grown much more ‘muscular’ since the 1950’s, and that this is perhaps a sign that society places more ‘value’ on increased muscle development and size in contemporary males, and this in a circular manner probably puts more pressure on adolescent males to increase their muscle size and strength due to perceived societal demands, and thereby increases the pressure on them to take anabolic steroids. There is also suggested to be an increase in the psychological disorder known as ‘muscle dysmorphia’ or ‘reverse anorexia’ in males, where (mostly) young men believe that no matter how big they are muscle size wise, they are actually thin and ‘weedy’, and they ‘see’ their body shape incorrectly when looking in the mirror. This muscle dysmorphia population is obviously highly prone to the use of (perhaps one should say abuse) anabolic steroids as a group. There appears to be also an increase in anabolic steroid use in the older male population group, perhaps due to a combination of concerns about diminishing ‘male’ function with increasing age, a desire to maintain sporting prowess and dominance, and a perception that a muscular ‘body beautiful’ is still desirable by society even in old age – which is a concern due to the increased cardiovascular and prostate cancer risks taking anabolic steroids can create in an already at-risk population group. There is also a growth in the number of women taking anabolic steroid / synthetic testosterone, both due to its anabolic effects and its (generally) positive effects on sex drive, and a number of women body builders use anabolic steroids for competitive reasons due to its anabolic effect on muscles, despite the risk of the development of clitoral enlargement, deepening voice, and male type hair growth, amongst other side effects, which potentially can result from females using anabolic steroids. Anabolic steroid use therefore remains an ongoing societal issue that needs addressing and further research, to understand both its incidence and prevalence, and to determine why specific population groups choose to use them.

It has always been amazing to me that a tiny biological molecule / hormone, which testosterone is, can have such major effects not only on developing male physical characteristics, but also on behavioural and social activity and interactions with other folk, and in potentially setting hierarchal structures in society, though surely this ‘overt’ effect has been attenuated in modern society where there are checks and balances on male aggression and dominance, and females now have equal chances to men in both the workplace and leadership role selection. Testosterone clearly has a hugely important role in creating a successfully functioning male both personally and from a societal perspective, but testosterone can also be every males ‘worst enemy’ without social and personal ‘higher level’ restraints on its potential unfettered actions and ways of working. It has a magic in its function when its effects are seen on my young son as he approaches puberty and suddenly his body and way of thinking changes, or when its effects are seen (from its diminishment) in the changes of a man in love or in a new father. Perhaps there is magic also in the reduction of testosterone that occurs in old age, as this is likely to be important in allowing the ‘regeneration’ of social structures, by allowing new younger leaders to take over from previously dominant males, by this attenuation of testosterone levels perhaps making older males ‘realize’ / more easily accept that their physical and other capacities are diminished enough to ‘walk away’ gracefully from their life roles without the surges of competitive and aggressive ‘feelings’ and desires a continuously high level of testosterone may engender in them if it continued to be high into old age. But testosterone has an ugliness in its actions too, which was evident in my time working as a bouncer in bars and clubs, when young men became violent with other young men as a way of demonstrating their ‘maleness’ to the young females who happened to be in the same club and were the (usually) unwitting co-actors in this male mating ritual drama which enacted itself routinely on most Friday and Saturday nights, usually fuelled by too much alcohol. Its ugliness is also evident on the sporting field when males kick other men lying helpless on the ground in a surge of anger due to losing the game or for a previous slight, despite doing so within the view of a referee, spectators and TV cameras. Its ugliness is also evident in the violence that one sees in fans after a soccer game preying on rival fans due to their testosterone levels being high due to watching the game, and in a myriad of other social situations where males try to become dominant to lever the best possible situation or to attract the best possible mate for themselves, at the expense of all those around them – whether in a social or work situation, or a Twitter discussion, or even a political or an academic debate – the ‘male posturing’ is evident for all to see in each situation, whether it is physical or psychological. Perhaps it was not for the sake of a horseshoe that the battle was lost, but rather because of too little, or too much, testosterone coursing around the veins of those directing it. There are few examples as compelling as that of the function of the hormone testosterone in making male behaviour what it is which demonstrates how complex, exquisite and essential the relationship between biological factors and psychological behaviour and social interplay is. What truly ‘makes up’ a man and what represents ‘maleness’ though, is of course another story, and for another debate!


Anxiety, Stress And The Highly Sensitive Person – Too Much Of Something Always Becomes A Bad Thing That Damages One In The End

I am one of those people that worries all the time. If there is an issue at work or at home that is of concern, I will up at 2.00 am in the morning wondering how best to solve it and worrying about it until I am sure it is solved. When all is as well as it can be I will find something to worry about – the plans for the future, pension funds (or lack of them), my kids health, anything and everything. In many ways this has been a good thing, as it has helped me always plan ahead, find solutions to problems and be aware of challenging situations as they develop, or even before they do. In many ways this has been a bad thing, as it means I get irritable and stressed when things are not working out well, and I am at the age when this continued mental ‘strain’ has the potential after many years of being the ‘status quo’ to cause cumulative physical damage to my body resulting potentially in such clinical conditions as migraines, high blood pressure, heart attacks, and strokes amongst others. There is clearly a genetic or physical environment component to this ‘worry’ state, as my father was very similar, and always seem to be worried when he was not almost overly exuberant and happy (there never was a middle ground with him, which made life as a child both fun and challenging), and for most of his adult life until he suffered a series of heart attacks in his early fifties, he smoked ninety cigarettes a day (and was in his early years ‘proud’ of this fact and his capacity to smoke prodigiously, given that in his era it was the ‘done thing’ to smoke) and was never to be seen without a cigarette in his hand, surely as an antidote for and a mechanism to assist him to cope with the stress he felt on a daily basis and which he surely worried about continuously. I have noticed since the advent of the mobile phone, during meetings I sit in at work, or when I go out for a social evening, folk around me check their phone for text messages or emails on a regular basis, with some folk doing so seemingly every few minutes, which is also surely a pathological sign of something ‘worrying’ these folk, or of a ‘worry’ type of personality in these folk who seem to need to check on information coming to them on an almost continuous basis. All these got me thinking about ‘worry’ – known clinically as anxiety – and what causes it to occur, and why some folk appear to feel it more than others and seem to be ‘highly sensitive’ to stressful situations.

Anxiety is defined as a worry about future events before they occur, and is different, though related, to the concept of fear, which is defined as a psychological reaction to current events. Related to both concepts are those of stress, homeostasis and allostasis. The theory of homeostasis suggests that our natural preferred state of existence is one where we are in ‘equilibrium’ with the environment in which we live, and our body and mind are in a ‘steady state’, free of requirements, needs and challenges. When this steady state we exist in is challenged, for example by low energy levels in the body, we notice this as a stressor to our steady state existence (‘hunger’ is the mechanism by which we ‘notice’ this particular stress factor), and this stress induces us to respond to it, by in this example generating actions and plans that will allow us to source and eat food, thereby increasing our body’s energy ‘levels’ back to the state in which we are comfortable and ‘happy’ with. Similarly if we become hot, we move to a place where cooler conditions exist. In more complex examples, if our social or community life changes in a way we feel uncomfortable with, we make plans and enact changes that will attenuate this social stress by either moving to a new place or environment, or taking steps to remove whatever or whoever is causing us discomfort if it is in our power to do so. The process of achieving stability, or homeostasis, using behavioural and psychological changes, has recently been described as allostasis (though some of us believe this is an unnecessary definition as the definition of homeostasis incorporates what is now described as allostasis). These allostatic responses attenuate stressful changes, or changes which are at least perceived as stressful by us, by means of releasing stress hormones in the body (for example cortisol) via the hypothalamic-pituitary-adrenal gland pathway in the body, or by activating the autonomic nervous system (for example the sympathetic nerves which are responsible for initiating ‘fight or flight’ responses in the body), or by releasing cytokines (which are humoral blood-borne ‘signallers’ which also induce a number of physical body responses to stress), or other systems which are generally adaptive in the short term. These pathways all induce a number of ‘general alarm’ or ‘specific response’ changes in the physiological systems and different organs in the body, such as increasing the concentration of glucose in the blood and re-distributing it to areas of the body that need it most as a result of the induced stress, increasing cardiac output, blood pressure and blood flow to specific organs in the body such as the muscles while reducing blood flow to the digestive and reproductive system, and altering the immune system response, amongst others – which all in turn lead to symptoms one ‘feels’ such as dry mouth, rapidly beating heat, increased breathing rate, shaking muscles, nausea, diarrhoea, and even dizziness and confusion in extreme conditions. Like all things, some stress and occasional activation of this stress response ‘allostatic’ system is beneficial to one both for reducing the targeted stress and for making the response systems more efficient by ‘practice’. But, like all things, if the stressor is not removed, or if multiple different stressors occur at once, and these responsive systems remain ‘wide open’, this can result in a status of ‘chronic response fatigue’ in these systems, and ultimately cause damage to the body by the very mechanisms which are designed to protect (for example a raised blood pressure allows blood to pumped quickly to targeted organs requiring increased blood flow for their optimal function, but chronically raised blood pressure causes ‘backflow’ problems to the heart which leads to heart failure eventually, or ‘forward flow’ problems to other organs such as the kidneys, which are eventually damaged by continuously increased blood pressure over a period of time). What is defined as the ‘allostatic load’ is the ‘wear and tear’ of the body (and mind) which increases over time when someone is exposed to repeated or chronic stress, and represents the physiological consequences of chronic exposure to the hormonal and neural responses described above which are ultimately damaging to the person who is ‘feeling’ the stress and whose body is continuously trying to react to it.

All of these allostatic responses are reactive to an already occurring, or perceived to be occurring, stressful situation or environment, and the sensation of fear would be the psychological accompanying emotion associated with perceiving such already occurring situations. But as described above, anxiety is somewhat different, in that it is a worry about future, rather than already occurring events. When one is anxious, one is thinking about all the potential, rather than actual, implications of possible scenarios that could occur based on ones ‘reading’ of current situations or events occurring around one that may, rather than will, occur and potentially impinge on one and possibly cause stressful situations at some time point in the future. Interestingly, anxiety ‘uses’, or is at least associated with, a number of the physical allostatic ‘response’ systems described above, such as the hypothalamic-pituitary-adrenal system, autonomic and interleukin systems, and a number of the symptoms of anxiety are associated with activity of these ‘fight or flight’ response systems and the physiological perturbations they induce. In episodes of acute anxiety (also known as panic attacks), symptoms including trembling, shaking, confusion, dizziness, nausea and difficulty breathing occur, all of which are induced by the allostatic stress-related pathways described above. While some anticipation of the future and resultant planning for it can only be good for one from a long term safety and security perspective, and therefore occasional anxiety can also be beneficial in ‘encouraging’ the planning of and ‘making ready’ future reactive plans for potential stressors one is concerned about after ‘reading the runes’ of one’s current life, generalized anxiety disorder is a clinical condition that is characterized by excessive, uncontrollable and often irrational worry about future events that occurs in between three and five percent of the population word-wide, where folk have a high level of anxiety about everyday problems such as health issues, finances, death, family / social / work problems, or anticipated catastrophic situations which are not commensurate with their actual level of probability of occurring. Individuals with chronic anxiety disorder have a wide variety of ‘psychosomatic’ (body and mind) symptoms, including fatigue, headaches, nausea, muscle aches and tension, numbness in their hands and feet, fast breathing, stomach pain, vomiting, diarrhoea, sweating, irritability, agitation, restlessness, sleep disorders and an inability to either control the anxiety and / or its physical symptoms. If not adequately controlled, generalized anxiety disorder can result in a number of what are known as chronic ‘lifestyle’ disorders, such as high blood pressure, diabetes, migraines, heart attacks and strokes, as well as depression or irritable bowel syndrome, as well as a host of what are defined as ‘psychosomatic’ disorders’. What causes an individual to develop a generalized anxiety disorder is currently not well understood (it occurs more often in folk who have a family history of it), but it most often begins to manifest itself between the ages of 30-35, but can also occur in childhood or late adulthood, and appears to ‘tap in’ and chronically activate the allostatic physiological response mechanisms described above.

Another interesting ‘relative’ of anxiety disorders is what has become known as the Highly Sensitive Person (HSP) ‘disorder’. Folk who are highly sensitive people have a high degree of what is known as sensory processing sensitivity, or in other words they appear to respond to, or be aware of physical body symptoms of stress and anxiety, or to social or environmental situations, to a greater degree than folk who do not ‘suffer’ from this disorder. Folk who have HSP ‘feel’ all these body allostatic responses in an extremely sensitive way, via mechanisms that are still currently not well understood. Because of this, they are also ‘hyper-aware’ of social situations or environments that may trigger the ‘release’ of these physiological anxiety / stress-related response pathways in their bodies (or vice versa and they may be hyper-aware of these social situations because of their natural ‘up-regulated’ physical sensory state). This HSP state is either a curse or a blessing (or both), as it makes folk who ‘suffer’ from it prefer low stimulation environments and try to construct their lives to avoid over-stimulation, and predisposes them potentially to higher risk of chronic stress / anxiety related disorders, but it also make them ‘feel’ life more, have more insight into and early awareness of developing social situations that others may not even be aware of, and make them more ‘intuitive’ to what is going on around them. Whether HSP folk have higher levels of anxiety or greater incidence of a generalized anxiety disorder is currently not well known, but given both ‘tap into’ the same allostatic physical body systems and mechanisms make it more likely that this is indeed so. It must be noted that the concept of a highly sensitive person has been differentiated from that of a hypersensitive person, who are defined as folk who over-react to any stimuli or slight. Folk with HSP may simply be quiet, appear introverted or ‘shy’, or are able to ‘hide’ their HSP ‘condition’, while hypersensitive folk are typically very challenging to deal with socially, but they also may have underlying anxiety as a cause of their over-reactions, ‘temper-tantrums’ and rages. The treatment of all of these different anxiety related disorders is challenging, and requires lifestyle change, psychological intervention (such as cognitive behavioural therapy) and / or medication, but there is always a relatively poor cure rate and a high degree of recidivism, and folk with anxiety and stress related disorders need to themselves understand, acknowledge and work on their underlying condition, though the problem for doing so is that a hyper-sensitivity responsive ‘state’ or condition is very difficult to understand, let alone treat. A number of folk use smoking, alcohol consumption, or avoidance behaviour, as methods of ‘dealing’ with their anxiety or high level of sensitivity, but these short term ’emollients’ create their own specific problems and may themselves paradoxically increase anxiety and stress in those that use them as a stress / anxiety reducing mechanism.

Worry, therefore, can be a useful thing to prepare one to enact future potential responses to what one is ‘picking up’ in one’s current circumstances that causes one to worry, if it continues for a short period of time only and if it is about a specific issue. Worry, if chronic or if it is a clinical disorder, through the allostatic pathways and circuits it uses to initiate and mediate ‘fight or flight’ body changes, can cause a wide array of unpleasant symptoms and diminish one’s quality of life, and can ultimately cause major physical damage to one’s body if one does not manage it carefully, or treat it as something that needs to be ‘cured’. The ‘trappings’ of modern society such as mobile phones and increased work and social connectivity and immediate communication capacity have many benefits, but these can also ‘tap into’ and reinforce these anxiety-related allostatic pathways and create continuous stress of their own making – it is likely that those folk who compulsively reach for their phones to check their messages every few minutes almost certainly have an anxiety disorder, or are prone to developing one, and future research is surely needed to ascertain the veracity of this possibility. I myself am a ‘worrier’, and almost certainly am a highly sensitive person, as was my father before me. This has created blessings and challenges both for us and those around us – life can be beautiful, but life can also be challenging, on a daily basis, with most of it ‘raging’ around in our own minds rather than in the ‘real’ life around us per se. At twenty five, I would have said the benefits of being and living such as a highly sensitive person and ‘worrier’ surely outweighed the challenges – the rose surely smelt better, the rain surely felt softer, the love was deeper, the anger stronger, the passion for life greater to and for us compared to how most folk around us probably experienced their less ‘perceived’ life. However, now I am about to reach the age of fifty, and am reaching the ‘tiger territory’ period of life for high blood pressure, heart attacks and other ‘diseases of a lived life’, I am not so sure, and the thought of a calm life, without worry, without stress, lived in soft colour and tranquil shades and hues, seems to be perhaps the better one, and one that should have been chosen as preferential way of living all those years ago, or at least changed to now I am more aware both of my own highly sensitive ‘condition’ and the potential negative effects such a life can have on one’s physical response mechanisms and body organs and physiological systems. But, at the end of the day, can one ever really ‘choose’ one’s own ‘sensitivity to stimuli’ levels? Perhaps our own anxiety and stress levels, or at least our own perception of them, were set in our ancestors body’s thousands of years ago and passed down to us, even if they are redundant as a ‘need’ in our modern life, and are therefore almost impossible to materially change despite our wishes and best efforts to do so. More research is needed to better understand if sensitivity to stimuli levels, and indeed those of anxiety itself, can ever be permanently attenuated, or rather if they stay permanently ‘as is’, and one merely learns rather how to cope and ‘deal with’ them better with the passing of time or with enhanced understanding, treatment or therapy.

One’s life will surely happen to oneself, as it does for each of us as we move through life and its challenges, whether one worries about it or not, or whether one ‘feels it’ more or less, I guess, but in many ways it surely ‘feels’ more like it is ‘happening to one’ when one worries about it than when one does not – though doing so appears to damage one’s physical survival mechanisms by over-use as part of the process. It must be wonderful to live a life in the always warm, always comfortable environment which is the one in which has no worries. But, equally, one can never maintain a hot fire without some internal combustion occurring which creates the heat, or even more so, put out a fire once it has been burning for a long time and has created the ‘heat’ which is manifestly evident in the life lived with maximal sensitivity to stimuli and responsivity to all around it. Would one choose to put this ‘fire’ out and reduce the ‘heat’ in oneself if one could do so? How one answers that question will perhaps ascertain for oneself where on the spectrum of anxiety and sensitivity to stimuli scale one is, or at least where one would like to be (without the need to reach for one’s mobile phone to get the answer to it as we do these days, or lighting up a cigarette in order to help one reflect on it like they did in my old man’s days). I’ll ponder this question myself as I listen with delight to the sound of the birds chirping in the garden outside that ‘feels’ as if they ‘pierce’ my ears, as I sip my coffee and go through what I have written this morning wondering if it has been a good or bad writing session, as I bang the table in frustration when I discover that my printer has run out of ink and I can’t print it out for my records, and as at the same time I worry if I have all my ‘ducks in a row’ ahead of those important meetings I have at work on Tuesday after the public holiday Monday. Reflect, reflect, reflect. Worry, worry, worry. For some there is no peace, even on the quietest of days!


Anterior Cruciate Knee Ligament Injuries – The End Of The Affair For Most Sports Careers Despite The Injury Unlocking Exquisite Redundant Neuromuscular Protective Mechanisms

I was watching a rugby game recently and saw a player land wrongly in a tackle and immediately collapse to the ground clutching his knee joint, and heard later that he had suffered a ruptured anterior cruciate ligament injury that would require nine months post-injury before he would be able to return to his chosen sport. Many years ago in my student days, after a few too many beers at a party, I jumped off a low wall, landed wrongly, and tore the meniscus in my left knee. The next day it had swollen up, but I did not think much of it and tried to drive to University, and always remember the horror I felt when getting to the bottom of the road and I tried to push in the clutch with my left leg to allow use of the brake at the stop street, and my leg would not react at all, and I only avoided an accident by turning off the car while working the brake pedal with my right foot. It always puzzled me afterwards why my leg would not respond at all despite my ‘command’ for it to do so, as even with the injury, I expected, while perhaps it might be painful to do so, that I would still have reasonable control over my leg movements, which appeared okay when walking slowly to the car and taking my weight on my uninjured leg. Perhaps this triggered a ‘deep’ interest in what controlled our muscles and other body functions, and when I started a PhD degree with Professors Tim Noakes, Kathy Myburgh and Mike Lambert as my supervisors at the University of Cape Town in the early 1990’s, I chose to look at neural reflexes and brain control mechanisms regulating lower limb function after anterior cruciate ligament knee injury. So what happens when the knee joint suffers a major injury, and can one ever ‘come back’ from it?

The knee joint is one of the most precarious joints in the body, and as compared to the hip and shoulder joints, which have quite a degree of stability generated by their ‘ball and socket’ design, it is simply made up of three individual bones (the femur, tibia and patella) moving ‘over’ each other while being attached to each other with a number of ligaments and muscles, which are pretty much all that creates stability in and around the knee joint. The knee mostly moves in a backwards / forwards (in medical terms flexion and extension) plane, and has a small degree of rotation inwards and outwards, but is basically a ‘hinge’ type joint that moves in one plane only. The major ligaments of the knee joint preventing too much flexion and extension are the anterior cruciate ligament (ACL), which prevents hyper-extension (the lower limb calf region moving too far ‘forwards’ relative to the upper thigh) and the posterior cruciate ligament (PCL), which prevents hyper-flexion of the knee joint. There are also relatively strong ligaments on each side of the knee joint (the medial and lateral collateral ligaments), as well as several ligaments and tendons securing the patella in place in the front of the knee. Two large pieces of cartilage, the medial and lateral menisci, ‘sit’ on the tibia and allow smooth movement to occur across the entire range of movement between the two big bones (femur and tibia) of the knee joint and protect each of these from damage which would occur if they ‘rammed’ into each other each time the bone moved without the protection of the two menisci.

While these ligaments (and there are several others in the knee joint beyond those I have described above), tendons and menisci provide the majority of support to maintain the fidelity of the knee joint, the surrounding muscles – particularly the quadriceps and hamstrings muscles – also provide important secondary support to the knee joint during active movement such as walking or running, when a greater degree of dynamic stability beyond the static stability the ligaments and tendons supply, is needed. So muscles are not just creators of movement, they are also important stabilisers of the body’s joints, and there needs to be a high degree of dynamic control of them by the central nervous system during movement to ensure things work ‘just right’ with not too much and not too little force being applied to the joint at any one time during any movement. The hamstring muscles have been shown to be agonists (assistants) of the ACL, and when they fire they ‘pull back’ the lower part of the knee joint so as to reduce pressure on the ACL when the knee extends to its limits, while the quadriceps muscles similarly assist the PCL from having too much pressure on it associated with too much flexion of the knee joint (though only at certain angles of the knee joint and not through its entire range of movement). Interestingly, the quadriceps muscles are not just agonists of the PCL, but also are ‘antagonists’ of the ACL, and their activation can also increase hyper-extension pressure on the knee joint (and therefore on the ACL) when the quadriceps contracts particularly when the knee is in an extended position. So the quadriceps muscles can be the ‘friend’ of the ACL and knee joint, but can also be its ‘foe’.

What is fascinating in this process is the structure and function of the nerve pathways both from and to all of the knee joint, ACL and muscles around them, and how these nerve pathways act differently in an intact ACL as compared to the damaged ACL state. In the intact ACL are mechanoreceptors (receptors which pick up mechanical pressure) which fire when the ACL is put under pressure / moves, and they send information back via nerves to the spinal cord, and cause increased firing of the hamstring muscles, in order to protect both the ACL and integrity of the entire knee joint. When the ACL is ruptured, receptors called free nerve endings in the surrounding capsule of the knee joint fire in response to movement of the entire knee joint, which would happen to a greater degree in the absence of the ACL after it ruptures, and importantly, these injury associated capsular free nerve ending reflexes don’t just increase the firing to the hamstrings muscles, they at the same time reduce firing to the quadriceps muscle, in order to protect the knee from further damage which could occur if the quadriceps were active maximally in the absence of the ACL. This free nerve ending pathway is known as a redundant pathway, as it only ‘fires’ when the ACL is damaged, and does not do so normally. Interestingly, the redundant free nerve ending related pathway does not seem to stop working even if the ACL is repaired or replaced, which means that even if one fixes the ligament materially, one cannot ever completely repair the sensitive neuronal control pathways as part of the operation.

While these redundant neural firing pathways are protective and are designed to help the knee from incurring further damage, they are unfortunately not helpful in allowing athletes who suffer ACL injuries from getting back to their full strength and a return to sport with the one hundred percent function they had prior to suffering the injury. The quadriceps muscles inhibitory firing pathway is particularly a problem from a return to sport perspective, as it means that the quadriceps muscles will always be weaker than before the ACL injury, and this is born out from most studies of quadriceps strength after injury, which show a continued deficit of at least 5-10 percent injured limb compared to the unaffected limb, and that is when rehabilitation of the injured limb is done post-injury or operation, and is even higher when it is not. Furthermore, the altered firing synergies, even those of the increased hamstring firing, appear to be sub-optimal from a functional pattern of movement perspective, even if they are protective, and there even appears to be whole body / both limb firing pattern changes, with athletes favouring the injured leg and taking more weight on the uninjured limb even if they are unaware of themselves doing this (though some folk speculate that using crutches for a prolonged period of time after ACL injury may be in part a cause of these whole limb and gait changes). These changes surely are at least to a degree responsible for the high rate of re-injury of the damaged ACL observed in those athletes who return to competitive sport after ACL injury, and potentially the high rate of ACL or other knee joint injury in the unaffected limb which some folk suggest occurs with return to sport after ACL injury.

So therefore, sadly for those who suffer ACL (and other) knee injuries and want to return to competitive sport, or to their pre-injury level of sport, redundant neural mechanisms between the knee joint and the surrounding muscles, while functionally being designed to give a measure of protection to the knee joint in the case where the ACL is damaged or absent, paradoxically ensures by its very activity that the function of the surrounding muscles is attenuated, particularly in the quadriceps muscle, and they will never have ‘full’ functional activity of the knee joint after the injury, despite them having a brilliant surgeon who performs a perfect mechanical replacement of the ACL surgically, and despite the best rehabilitative efforts of either the athlete or those assisting them with their rehabilitation. An athlete has two choices after suffering an ACL injury (and other associated ligament injuries which worsen the prognosis even more). Firstly, they can attempt to return to their sport as they did it before their injury but with changing how they perform it by ‘compensating’ for their injury – if in team sports by improving other aspects of their game so that their reduced capacity for agility and speed after injury is not ‘noticed’, and in individual sports by altering pacing strategy or style of performing their sport (though particularly in individual sports this is not really an option and the loss of competitive capacity is ‘painfully obvious’), and with the awareness that that they have a good chance of re-injuring themselves. Secondly, they can downgrade their expectations and level of sport, either retiring from their sport if competitive or changing the level of intensity they routinely perform their sport to a lower level, as hard as it is for athletes to come to terms with having to do this. But there is no ‘going back’ to what life was like before the injury, and this creates a potential ethical dilemma for those involved in rehabilitating athletes after ACL injury – if one works on increasing for example their quadriceps strength, one is ‘going against’ a natural protective mechanisms ‘unlocked’ by the ACL injury, and one may be paradoxically increasing the chances of future damage to the athlete by the very rehabilitation one is trying to help them by doing it, and one should perhaps rather be ‘rehabilitating’ them by working on their psychological mindset so that they are able to come to terms with the concept of permanent loss of some function of their injured knee and the need to potentially look for alternative sporting outlets or methods of earning their salaries.

The wonderful period of my life as a PhD student back in the early 1990’s, learning about these exquisite neuromuscular protective mechanisms surrounding the knee joint that are ‘activated’ after knee ligament injury (and potentially meniscal injury too), started a lifelong work ‘love affair’ with the brain and the regulatory mechanisms controlling the different and varied functions of the body, that has lasted to this day, and ‘unlocked’ a magical world for me of neural pathways and complex control processes that has ensured for me a lifetime without boredom and never a moment when I don’t have something to ponder on, apart from initiating an amazing ‘journey’ trying to understand how ‘it all works’. But this scientific exploration has not helped me fix my knee joint after the injury all those years ago – my left leg has never been the same again after that injury which required a full meniscectomy eventually as treatment, and still swells up if I run at all and even if my cycle rides are too long, and the muscles around the affected knee have never been as strong as they were no matter how much gym I do for them. So by understanding more about the nature of the mechanisms of response to something as major as anterior cruciate ligament knee injury, I have also come to understand more about the concepts of fate and acceptance of things, and that a single bad landing (or indeed having one beer too many leading to that bad landing) can create consequences that there are no ‘going back’ from, and that will change one’s life forever. After a bad knee injury, nature has given us the capacity for a ‘second chance’ by having these redundant protective mechanisms, but that second chance is designed to work at a slower and more relaxed pace, and with the caution of experience and the conservatism the injury engenders, rather than with the freedom of expression that comes with youth and the feeling of invincibility associated with it. Rivers do not flow upstream, and we don’t get any younger as each day passes, and our knee joints sadly will never be the same again after major injury, despite the best surgery and rehabilitation that one gets and does for them. Nature ensures this ‘reduction in capacity’ happens paradoxically for our own ‘good’, and the biggest challenge for clinicians is to understand this and convey that message to the athletes they treat, and for athletes it is to accept this potential ‘truism’ too, and let go of their sporting ambitions and find a quieter, more sedate life sitting on the bank of the river they used to ride the flow of prior to suffering their knee injury. But please left knee, let me have a few more good bike rides in the cool morning air far from the madding crowd, before you pack up completely!


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