Category Archives: Brain Function

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!

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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!


Chronic Fatigue Syndrome – Is This Contemporary Neurasthenia An Organic Neurological Or Psychiatric Disorder Associated With Childhood Trauma Related Chronic Anxiety And Resultant Ego Depletion

I was watching the Two Oceans running marathon in Cape Town yesterday on the square box, and marvelled not only at the aesthetic beauty of Cape Town, but also at how many folk of all ages ran the iconic race, and at their visible efforts to resist the sensations of fatigue they were clearly all feeling as the race reached its endpoint and as they laboured valiantly to reach the finish line in the fastest time possible for each of their abilities. Some recently published top-notch research articles on the mechanisms of fatigue by Roger Enoka, Romain Mueusen and Markus Amman, amongst others (surely with Simon Gandevia the scientists who have shaped our contemporary view of fatigue more than anyone else) have been doing the ’rounds’ amongst us science folk on research discussion groups the last while, and has ‘reignited’ an interest in the field in me. A large period of my research life was involved in trying to understand the mechanism behind the symptoms of fatigue, mainly in athletes, but also in those suffering from the clinical disorder known as chronic fatigue syndrome. As I come up quickly to the big age of 50 later this year, I notice that the daily physical and mental activity which I used to do with ease in my youth fatigue me more easily now. Because of this I have to ‘pace’ myself more carefully in all aspects of life to ‘preserve’ energy to ‘fight the good fight’ another day, in order to not run the risk of collapsing completely in the manner I witnessed in those folk with chronic fatigue syndrome I tried to assist both as a clinician and scientist during my earlier career, who pushed too hard and subsequently became moribund because of it. All of these recent observations have got me thinking of chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME), what causes it, and why it manifests in some folk and not others.

Fatigue is a complex emotion which is felt by all folk on a daily basis, but paradoxically is very difficult to define. It has mental and physical symptoms and signs, and is often increased by and related to exertion of any kind. Fatigue can be either acute, where there is a direct correlation of the symptoms of fatigue to a specific task or activity and the symptoms attenuate when the activity ends, or can be chronic, when the symptoms of fatigue remain for a prolonged period and are not attenuated by a period of rest, and the reasons for these chronic symptoms remaining are very difficult to understand. In the sporting world, chronic fatigue is caused by pushing oneself too long and too hard in training and racing, and is known as over-training syndrome, and has a symptom complex which includes apart from the symptom of extreme fatigue also those of ‘heavy legs’, increased waking pulse rate, sleep disorders, weight loss (or weight gain), lack of motivation, depression and decreased libido, which do not improve unless there is a prolonged period of rest with no physical training. Working at the University of Cape Town with great scientists Mike Lambert, Liesl Grobler, Malcolm Collins, Karen Sharwood, Wayne Derman, and others, for my medical doctorate in the late 1990’s we examined athletes who were moribund from over-training, and found that a number of them had pushed themselves so hard and so long that they had developed skeletal muscle pathology (damaged mitochondria in particular) to go with all these chronic fatigue symptoms, and we called this symptom complex the fatigued athlete myopathic syndrome, and later acquired training intolerance. The words the athletes we examined used to describe their symptoms were classic and perhaps ‘explained’ the issues better than scientific or medical terms – with one sufferer declaring that they had ‘no spring in the legs’, another that ‘one kilometre now feels what equalled 100 km previously’, and another that ‘at its peak, the fatigue left me halfway between sleeping and waking most of the time’. Although there was perhaps a degree of hubris in these self-reported symptoms of fatigue, all these folk felt that the symptoms profoundly affected their exercise performance and lifestyle. Significantly, the majority of folk had evidence of suffering from depression, and also did not want to stop training and racing, and indeed found it almost impossible to stop training and racing despite these profound symptoms of chronic fatigue.

I carried on my interest in this field when moving to Northumbria University in the UK in 2006, and assisted Paula Robson Ansley and her PhD student Chris Toms, who did some great work examining causation, clinical testing of and exercise prescription for folk with classical chronic fatigue syndrome, as opposed to those with acquired training intolerance (though there is surely a relationship between these syndromes). Folk with CFS have symptoms of chronic and extreme fatigue which is persistent or relapsing, present for six months or longer, not resulting from ongoing exertion, not attenuated substantially by rest and causing impairment of activities which were previously easy to perform. They also have four or more ‘other’ diagnostic criteria, including impaired memory or concentration, sore throat, tender cervical / axillary lymph nodes, muscle pain, multi-joint pain, headaches, unrefreshing sleep or post-exercise malaise. It is importantly a diagnosis of exclusion of other medical causes of fatigue such as cancer, TB, endocrine or hormonal imbalances, or psychiatric or neurological disorders, and a clinician must always be careful to exclude these specific organic medical causes before diagnosing someone with CFS. The cause of CFS is unknown and hotly debated – it is usually precipitated by a viral infection such as Ebstein Barr Virus infection (glandular fever), and viral or infective causes, immune function issues, toxic pathogens or chemicals have all been suggested to be the cause of CFS, but not all folk who have CFS have any or all of these potential triggers or causal agents as part of their presenting history. It is notoriously difficult to treat, and some folk are left moribund and with significantly impaired lives for decades, although in some folk the syndrome seems to ‘burn out’ and they improve with time or learn to live with their symptoms by managing them carefully. Unfortunately there is a high level of suicide in folk suffering from CFS, though it is not clear if this is related to the underlying causation of the disorder or due to its long-term effect on lifestyle and physical capacity.

What is interesting (and of concern) for those folk studying CFS and trying to understand its aetiology and how to treat it, is the controversy and level of emotion attached to its diagnosis and treatment. Chronic fatigue syndrome used to be more well known as myalgic encephalomyelitis (ME), first diagnosed in the 1950’s after a group of doctors and nurses in a specific hospital developed post-viral syndrome with symptoms including chronic fatigue and with some neurological muscle and central nervous system related symptoms (hence the name ME) and it was first thought to be a neurological disorder. But with time, and as it was found that more folk who were diagnosed with ME did not have classic ‘organic’ neurological signs, it became thought of more as a psychiatric disorder and became more often described as CFS, due to the predominant symptomatology of fatigue as being the major ‘descriptor’ of the disorder. What is astonishing is that, as well described in a fascinating article by Wotjek Wojcic and colleagues at Kings College, London, in a survey of neurologist specialist members of the British Neurologist Association, 84% of respondents did not view CFS as a neurological disorder but rather as a psychiatric disorder. But, paradoxically, a number of patients with CFS would prefer it to be described as a neurological rather than a psychiatric disorder (and would prefer it to be still called ME), because of the social stigma of the label of having a psychiatric disorder. Somewhat astonishingly, as described by Michal Sharpe of the University of Edinburgh, there was even a negative response to a study of his which found that cognitive behavioural therapy and graded exercise therapy (the PACE trial) helped improved the symptoms of sufferers of CFS/ME, with several major patient organizations apparently dismissing the trial findings and being critical of them, because the findings could suggest that the syndrome was psychiatric in origin if cognitive behavioural therapy worked, rather than what would be the case if it was an organic neurological disorder, in which case such therapy should not work. As Sharpe concluded, in his own words it is a ‘funny old world’ when a study shows that a therapy works, but patients are angry because they didn’t want it to work, because of the stigma it would potentially create by it working.

Wojcic and colleagues also made the point that the majority of symptoms of CFS are almost identical to that of neurasthenia, a psychiatric disorder which was prominent in the 1800’s and early 1900’s, but has become almost unheard of as a diagnosis in contemporary times. Neurasthenia was described as a ‘weakness of nerves’ by George Beard in 1869, and as having symptoms of fatigue, anxiety, headache, heart palpitations, high blood pressure, neuralgia (pain along the course of a specific nerve) and depressed mood associated with it. The ICD-10 definition of neurasthenia is that of having fatigue or body weakness and exhaustion after minimal effort, which is persistent and distressing, along with depressive symptoms and two of the symptoms of either muscle aches and pains, dizziness, tension headaches, sleep disturbances, inability to relax, irritability and dyspepsia (indigestion). William James referred to neurasthenia as ‘Americanitis’ (he suffered from neurasthenia himself) as so many Americans in the 1800’s were diagnosed with it, particularly women, and it was a ‘popular’ diagnosis whose treatment was either a rest cure or electrotherapy. In world war one neurasthenia was a common diagnosis for and of ‘shell shock’, and folk with shell shock related neurasthenia were treated with prolonged rest. In the 20th century neurasthenia was increasingly thought of as a behavioural rather than a physical condition, and eventually it ‘fell out of favour’ and was ‘abandoned’ as a medical diagnosis. As Wojcic and colleagues suggest, not just the symptoms, but the ‘trajectory’ of the classification of the disorder have and follow a strikingly similar pattern to that of CFS/ME, which also started off as being diagnosed as an organic / neurological disorder and is now thought of a psychiatric disorder, which is (sadly) increasingly stigmatized by lay folk and indeed even some clinicians.

Neurasthenia was thought by Beard to being caused by ‘exhaustion’ of the central nervous system’s energy reserves, which he attributed to the (even in those days) stresses of urbanization, increasingly competitive business environment and social requirements – it was thought that neurasthenia was mostly associated with ‘upper class’ folk and with professionals working in stressful environments. Sigmund Freud thought there was a strong relationship to anxiety and to the basic ‘drives’, and as he almost always did, related neurasthenia to ‘insufficient libidinal discharge (ie not enough sex) that had a poisonous effect on the organism’. Both Freud and Carl Jung believed that drives were the result of the ‘ego’ state, and that disorders such as neurasthenia were a result of imbalances in this ego state. In their model, the ‘id’ was the basic component of the subconscious psyche which encompassed all our primitive needs and desires. The ‘ego’ was the portion of the psyche which maintains the sense of self, and recognizes and tests reality. A well-functioning ego perceives reality and differentiates the outer world from inner images and desires generated by the id, and ‘controls’ these. The ego develops in the first part of life, and is associated with a history of object cathexes. Cathexes are attachments of mental or emotional energy upon an idea or object. Object cathexes are generated by the id, which ‘feels’ erotic and other ‘trends’ as needs. The ego, which to begin with is feeble, becomes aware of these object cathexes, and either acquiesces or understands these needs and manages them (and thus becomes ‘strong’) or is disturbed by them and ‘fends’ them off by the process of repression (and becomes weak and ‘conflicted’). If weak, the ego deals with its inadequacy by either repressing unwanted thoughts (thrusting back by the ego from the conscious to the unconscious any ideas of a disagreeable nature) or developing a complex (a group of associated, partially or wholly represented ideas that can evoke emotional forces which influences an individual’s behaviour, usually ‘outside’ of their awareness). As a result of these complex developments, folk either use projection, which is a mental mechanism by which a repressed complex is disguised by being thought to be belonging to the external world or to someone else, or transference, which is the ‘shifting’ of an affect from one person to another or from one idea to another, either affection or hostility, based on unconscious identification, in order to deal with them at a subconscious level. Albert Adler described the inferiority complex as such – that a combination of emotionally charged feelings of inferiority operates in the unconscious to produce either timidity, or as a compensation, exaggerated aggression or paradoxical perception of superiority, and ones drives were a result of, or compensation for, feelings of inferiority derived from previous unpleasant experiences. For example, competing in extreme sport would be a compensation for being bullied in the past, or being abused as a child, or being ignored by a parent when young. Signs of such complexes included for Freud and Jung disturbing dreams and ‘slips of the tongue’, nervous tics and involuntary tremors, fanatical attachment to projects and goals, envy and dislike of individuals who are successful, falling apart when failing to successfully complete a challenge, desire for public acknowledgement and seeking of title and awards, compulsive exercising, and the development of neuroses and psychoses, all of which can be used to diagnosed the presence of ‘unsolved’ complexes, projections and transferences. Importantly for the development of neurasthenia (and chronic fatigue), Jung and Freud thought that there was an ‘energy cost’ to maintaining repressions and their associated complexes – Freud defined drives as the ‘psychical representative of the stimuli originating within the organism and reaching the mind, as a measure of the demand made for work in consequence of its connection to the body’ – and this energy cost eventually leads to the ‘breaking down of the will’ by the constant ‘fighting’ to maintain what was ‘hidden’ that was painful and not wanting to ‘come out’, and this breakdown of the will / ‘mental exhaustion’ lead to the signs and symptoms described above, which could in a circular way be used to diagnosed the presence of the underlying disorders. In a positive final observation, both Jung and Adler thought that the psyche was self-regulating, and that the development of these symptoms was purposive, and an attempt to ‘self-cure’ by compensation, and by bringing the destructive repressions, which exist at a subconscious level so are not directly perceived by the folk who have them, to their attention, or at least to that of their clinician or therapist, it would eventually lead to cure or at least ‘individuation’ and acknowledgement of the underlying issues, which to therapist of that era was the start of the cure.

Therefore, in this ‘id and ego’ model developed by Freud, Jung and their colleagues all those years ago, symptoms of chronic fatigue and burnout may be the psyche’s way of creating knowledge of and thereby attempting to cure latent psychic drives which lead to obsessive work or sporting goals and activity, created by past psychological trauma and a resultant ‘weak ego’, which results in chronic fatigue when the psyche cannot ‘cope’ with ‘fighting’ these often unperceived issues for a long period of time / for the life period up to the point when they collapse. Interestingly, while these theories have been mostly long forgotten or have fallen into disfavour, there has recently been an increase again in interest in the concept that mental and physical ‘energy’ is a finite commodity, with psychologist Roy Baumeister’s theory of ‘ego depletion’ gaining much traction recently, which suggests that a number of disorders of ‘self-regulation’, such as alcohol addiction, eating disorders and obesity, lack of exercise or excessive exercise, gambling problems and inability to save money and personal debt, may be related to one using up one’s ‘store of energy’ resisting the ‘deep’ urges which lead to these life imbalances, and eventually willpower decreases to a level where one cannot resist ‘doing’ them, or cannot raise the effort to continue resisting the desire to act out one’s wishes. In Baumeisters own words a tempting impulse may have some degree of strength, and so, to overcome it, the self must have a greater amount of strength, which can eventually be worn out or overcome, leading to adverse lifestyle choices in this ‘impaired mental energy state’. All lifestyle diseases and disorders may in his model therefore be related to an insufficiency of self-regulatory capacity, and there is an energy cost to resisting the ‘urges’ that lead to poor lifestyle choices, that may with time lead to either acute mental or physical fatigue, or in extreme cases to the development of chronic fatigue. Like with most contemporary psychology, the underlying reasons for such potential eventual failure of self-regulation were not deeply examined by Baumeister to the level that it was by Freud, Jung and colleagues, perhaps because so much of Freud, Jung and Adler’s theories are difficult to prove or disprove and therefore psychology and psychiatry have in the last few decades ‘turned against’ their theories and embraced neuroscience as having the best chance of understanding how the mechanisms underpinning self-regulation or the lack of it ‘work’, but neuroscience is currently far too ‘weak’ a discipline methodologically wise to be able to do such. Having said this, it is surely important that folk like Roy Baumeister are re-breaking such ground, and our understanding of such complex disorders such as CFS, and others such as fibromyalgia, which are also complex diagnostic dilemmas, is enhanced by the insight that mental energy ‘ego’ depletion may play a part in them. Sadly, there is evidence (described by Tracie Afifie and colleagues at Manitoba and MacMaster Universities) that folks who suffered physical or sexual abuse in childhood, or were exposed to between-parent physical violence at a young age, have an increased association with a number of chronic physical conditions (including arthritis, back problems, high blood pressure, migraine headaches, cancer, stroke, bowel disease, and significantly also CFS), and also a reduced self-perceived general health in adulthood, all of which would support the ‘ego and id’ psychopathology development theories of Freud and Jung to a degree, though of course surely not all folk who develop CFS have such childhood trauma issues.

Like the definition of neurasthenia and CFS, perhaps our understanding of their ‘deep causes’ is also moving in a ‘full circle’, and our knowledge of the underlying causes of CFS, if it does not have a specific organic or viral / toxic cause, needs to reconsider these basic concepts proposed by Jung, Freud and Adler more than one hundred years ago, and currently appears to be potentially re-occurring in a ‘repackaged’ version as suggested by Baumeister and his contemporaries theories in recent times. Perhaps the drive to keep on exercising that we found in all those athletes we examined in our studies at the University of Cape Town all those years ago was the key factor in the cause of their chronic fatigue, and was an ‘external’ manifestation of issues that they were not even aware of. We did not know enough about the subject back then to even ask them about it when we were trying to understand the causation of their symptoms. Perhaps a major component of CFS is mental exhaustion associated with continuously ‘fighting’ underlying past psychological trauma that the folk suffering from it are not even aware of, or at least this is part of the cause of the symptom complex along with other more organic or infective causes. Of course describing a disorder as either neurological or psychiatric is reductive, and indeed dualistic, and surely similar physical brain neural mechanisms underpin both ‘neurologic’ and ‘psychological’ disorders which we just cannot currently comprehend with the research techniques currently available. One has try to understand the reasons why one is ‘driven’ to do anything, particularly as one gets older and one’s physical (and perhaps mental) resources diminish and need to be ‘husbanded’ more carefully, though paradoxically CFS is a disorder which afflicts folk most often initially in their early twenties, and often ‘burns out’ / attenuates with increasing age, perhaps because part of growing older is often about understanding one’s issues to a greater degree, dealing with them, and living more ‘within one’s means’ all of materially, socially, physically, mentally and spiritually (although for some folk such learning never occurs). Aging may therefore be curative or protective from a CFS perspective (or one may die of ‘corollary damage’ such as heart attacks rather than developing CFS as a result of chronic stress related to unfulfilled drives).

Fatigue as a symptom is surely the body and mind ‘telling us’ that something is not ‘right’ and we need to rest – either acutely when we are doing sport, or chronically when we are ‘fighting’ something we do not understand or are aware of. The challenge is for us not just to rest, but to try and understand why we so often resist resting (well, those of us with complexes rather than those of us who are completely self-actuated and do not have stress or drives), and why life balance is so hard for many folk to find. The need (or unwanted requirement) for a prolonged rest / period of avoidance of one’s routine life / a ‘long sleep’ is often perhaps the last resort of those who are chronically fatigued and is nature’s way of ‘telling’ folk that they have ‘run out’ of responsive resources, and healing will not happen without it, though the healing may paradoxically be not of the fatigue itself, but of its underlying ‘deep’ causes. Now I am finished this its time to rest, and ponder what caused the need to write it in the first place, and why I have spent my holiday Easter period preparing for its writing, and ‘stoking the creative demon’ which never rests and which surely eventually damages one even as it creates, rather than just sitting in a coffee shop watching the world go by and thinking of nothing but how nice the next sip of coffee is sure to be. Demons of the past, away with you, before you lead to permanent mental and even physical damage, and tire folk out in the process!


Information Processing In The Brain And Body – Are We Managed By And Do We Regulate Our Lives Using Discrete Units Of Information Rather Than A Continuous Flow Of Knowledge

I have been spending quite a bit of time at work since I started my current role as a Head of a Medical School two years ago trying to get data ‘dashboards’ together of all aspects of our business profile, so I can better understand our strengths and weaknesses, and make informed decisions on how to strategically improve what we do and how we do it. On the home front we are making some plans to change our living environment, and are gathering data to make the best possible decision before doing so with the information we have available to us. Most of my life I have been a research scientist, and generating and understanding data has been the ‘trademark’ of my working life. One of the major challenges left for science and us scientists to solve is the understanding of basic brain function and the brain’s capacity for dynamic regulation of the body’s activity. A major component of this endeavour is understanding how the brain responds to information flow from the body, how it analyses this information it receives, how it comes to a decision to act (or not act) based on this information analysis, and how it generates information flow back to the body in order in order for it to respond to and / or make changes as a consequences of these decisions. Most of the time life ‘feels’ as if it occurs in an ‘always happening’, linear, continuous manner, and there are no apparent ‘gaps’ in our conscious awareness of activities occurring either around us or in which we are ourselves functioning and required to make decisions about. But, us scientists when examining brain and body function, ‘break up’ the information we record from a research participant we are observing into discrete data units, using a variety of physiological laboratory assessment equipment, which are recorded and stored as such, and we later print these data out or put these recordings into spreadsheets as numerical data, and create line or bar graphs in order to understand and explain what we have observed. The question therefore arises if as part of the inherent brain and body regulatory mechanisms which manage our daily life activity, do we similarly understand and assimilate an understanding of activity occurring in and around us in such an information processing / discrete data based way?

One of the most pivotal moments of my research life was working with the peerless Neurologist Dr Bernhard Voller as a Research Fellow at the National Institutes of Health in Washington DC, fifteen years ago, when he showed me how to perform the technique of fine wire invasive recording of skeletal muscle activity (known as electromyography). When we had placed the electrode in a muscle (we examined the nerve firing in eye muscles for the particular experiment), and the subject blinked, one heard the firing of the nerves controlling the muscle via a speaker attached to the electrode recording device, and the rate of firing increased rapidly each time the subject blinked with greater force. What was such a ‘wow factor’ for me, was that what we were listening to was the information ‘code’ going down from the brain to the specific muscle we were studying, in order to make it contract with the required force. If you put a similar electrode into any nerve in the brain or travelling from the brain to the body, you will see or hear a similar firing rate change happening, which is the ‘code’ used by the brain to generate commands and induce changes in function of any organ the nerves target. One of the most interesting studies I have ever read looked at single neuron firing in the motor cortex of a monkey’s brain when its arm was being moved in different directions around its elbow joint. Each movement created a different ‘code’ of firing which was unique to each specific movement, and if one looked at the graph plots of the generated data after learning the different ‘codes’ for each movement, one could predict with a high degree of certainty which arm movement had occurred to produce each specific trace. So certainly at the physical nerve firing level, information is generated, and function regulated, by discrete coded information that was evident and could be ‘decoded’ when examining a particular nerve’s firing rate.

This numerical coding of information is also evident across a variety of body systems. For example, heart rate is a measure of how fast the heart beats, and we know that when the heart beats faster it is working harder in response to a greater need for blood flow around the body, such as when doing exercise, or during a hot day, or when one is sick and has a fever. So if we examine a heart rate trace collected during a 24 hour period of time from someone, without being told what the person whose heart rate we were retrospectively examining had been doing, we could make a good guess of what activities the person had been involved with at different stages of the time period their heart rate was assessed. For example, if the heart rate is very high for an hour or two in the early morning or evening period, one can assume with a high degree of certainty that this is probably caused by the performance of a bout of exercise. In contrast, if heart rate is very low for an extended period of several hours in the evening time, one can guess that this would be associated with a period of time when the participant was sleeping. Another very interesting study for me was one that examined the output of neurotransmitters (a chemical substance) when a varying change in firing rate was artificially induced in a neuron ‘upstream’ of the synapse where the neurotransmitter was released, and it was found that the release of neurotransmitter occurred in a discrete pulsatile manner that was directly correlated with the ‘upstream’ induced firing rate. This indicates that the ‘fidelity’ of the rate coded neural message was maintained even by chemical substances, and that regulatory information is not confined in complexity or content only to neuronal firing mechanisms, but occurs also in blood borne / neurochemical substrates.

In order for this ‘rate coded’ information to be created and interpreted, some yet unidentified algorithmic processes in the brain needs to break it up into ‘useable’ bits or chunks of information of a certain length or period of time, and the interpreting algorithm needs to have a ‘pause’ in order to both make sense of this information and respond to it, before ‘receiving’ and responding to further information from the same source. If information arrived in a continuous stream that was not ‘broken up’ into ‘bits’ of information, no interpretative sense could be made of it, and no logical response based to the information encoded in it could be initiated. We have previously suggested that information must occur as, or be broken up by the brain into, ‘quantal packets’ of information, and each ‘quantal packet’ of information is used by the brain to make sense of what is required by whatever initiated the perturbation that lead to the generation of the information flow, and how the brain needs to respond to the information. There is surely always alternating periods of ‘certainty’ and ‘uncertainty’ occurring related to the flow of information in the brain and body – certainty when a coherent quantal packet of information is received and ‘understood’, and uncertainty in the periods prior to the full required quantal packet of information being received, or during the period after the full quantal packet of information was received and a response to it enacted, during which time and after which further information from the original source will be required to assess whether the response was satisfactory and / or fulfilled the need that caused the original information to be generated. So the passing of time is a fundamental requirement of information flow and the understanding of it, and there will always be alternating time periods of certainty and uncertainty related to the information flow. What length of period of time or quantity of information is required to create a period of certainty in any brain or body system is likely to be a product of the type of substance which creates the information (ie shorter in nerve tissue and longer in humoral / blood substance), what purpose the information is created for, and the complexity of the issue the information is associated with.

Clearly from the above examples, a strong case can be made that information coding underpins the regulation of physical brain and body function. However, it is more difficult to understand how cognitive (mental) information we receive from the external world is ‘managed’, and if and how we ‘break it up’ into useable ‘bits’ of discrete information that can be made sense of by our algorithmic information processing functions of the brain. Most data would suggest that we do indeed break up information of social or environmental situations into at least categorical (for example need to respond / not respond) information. My esteemed colleague at the University of Worcester, Andy Renfree, has looked at decision making theory in relation to physical activity and shown that we make cognitive decisions on future levels of activity or plan for future activity based on either rational (taking all factors into account) or heuristic (using past experience to attenuate the complexity of decision making requirements) information and cognitive decision making, using differentiated information about one’s own current physical capacity and performance level, environmental factors, and the capacity of other individuals one is competing against, amongst a number of other factors. Knowledge of all possible behavioural outcomes, and an assessment of the potential risks to oneself of all the potential outcomes, as well as their potential rewards, are surely also individually assessed as part of any action related decision making process. However, cognitively and consciously it never ‘feels’ that all such factors are so individually and discretely assessed, but rather that life occurs as a ‘smooth’, continuous activity, with no perceptual ‘gaps’ occurring when decisions are being made or when cognitive uncertainty must be occurring. This ‘smooth’ conscious perception of life with no ‘gaps’ in it may occur because we do not focus on a specific thought, activity or sensation for any extended period of time, and rather ‘switch’ our attention continuously between different issues we are ‘working through’. Therefore, as a number of different thoughts related to different issues ‘intrude’ sequentially on our consciousness, this may ‘fill the cognitive gaps’ which would occur as a necessity when making cognitive decisions on any one specific issue or requirement, in the time periods of uncertainty before a cognitive ‘decision’ is made about any one ‘issue’ one is dealing with. It is obviously very difficult to research this area of cognitive information processing, given our lack of knowledge of core brain function, and the difficulty of being able to objectively assess one’s continuous real-time thought processes with the current laboratory research techniques available to us, which are still very crude and retrospective / mostly qualitative in nature.

While life as we know it may thus appear to occur as a continuous flow of activity and events which we respond and react to, how we interpret these activities and events and regulate our responses to them may indeed occur in a discrete information based numerical manner, replete with information ‘gaps’ and periods of uncertainty interspersed with ‘quantal packets’ of information rich certainty time periods, that each vary in length dependent on the complexity of the situation being assessed, the processes being used to assess it, and the physical substances in the brain and body used to assimilate and understand them. Information processing and decision making underpins all regulation of our brain and body functions and our successful interaction with the socially and environmentally challenging external world in which we exist. Our successful reaction to changes in either external environments or our internal physiological milieu depends on the successful generation of information describing these changes, the successful interpretation of this information, and the successful generation of actions in response to this information. At the neuronal level simple firing rate and rate coding underpins all information flow, and our physical responses are related to changes in this ‘code’ and the information encoded by these firing rate changes. To better understand the manner in which this information processing occurs in more complex issues is a lifetime of work in the time ahead for us neuroscience and information science folk. But, perhaps us scientists use discrete numbers and data to makes sense of how things work, because at the level of brain and body regulation and control, information flow and discrete data generation and assessment are the conceptual requirements underpinning all successful life activity, and us scientist folk are merely copying the ‘instruments and methods’ of the master designer who created us in the way we have been created when we do such work, whatever that master designer is or was. Time will tell if this is true or not, but, pertaining to our domestic decision-making requirements relating to whether we should stay in our current environment or move to another – brain neurons, was that one click or two I heard when you fired as I was thinking on this issue a moment ago!


The Sensation Of Fatigue – A Complex Emotion Which Is Vital For Human Survival

After a couple of weeks back at work after a great Christmas season break, I have noticed this week a greater than normal level of fatigue than I normally ‘feel’ at the end of a routine working week. After one of the hottest December months on record in my current home town, where temperatures for a while were consistently hovering around forty degrees Celsius, we have had a wonderful rainy, cool period, and I have noticed that I feel less fatigued in the cooler environment, and routine daily activities seem ‘easier’ to perform than when it was excessively hot. As part of a New Year’s resolution ‘action plan’ to improve my level of fitness, I have increased my level of endurance exercise, and as always have enjoyed the sensation of fatigue I feel towards the end of each long (though I know that ‘long’ is relative when compared to younger, more fitter folk) bike ride I do as part of this ‘fitness’ goal. All of these got me thinking of the sensation of fatigue, an emotional construct which I spent a great many years of my research career trying to understand, and which still is very difficult to define, let alone work out its origins and mechanisms of elicitation in our physical body structures and mental brain functions.

As described in these three very different examples from my own life, fatigue is experienced by all folk on a regular basis in a variety of different conditions and activities. Perhaps because of this, there are many different definitions of fatigue. In clinical medicine practice, fatigue is defined as a debilitating consequence of a number of different systemic diseases (or paradoxically the treatment by a variety of different drugs) or nutritional deficits. In exercise physiology, fatigue is defined as an acute impairment of exercise performance, which leads to an eventual inability to produce maximal force output as a consequence of metabolite accumulate or substrate depletion. In neurophysiology, fatigue is defined as a reduction of motor command from the brain to the active muscles resulting in a decrease in force or tension as part of a planned homeostatic process to prevent the body from damage which could result from too high a level of activity or too prolonged activity. In psychology, fatigue is defined as an emotional construct – a conscious ‘sensation’ generated by the cognitive appraisal of changing body or brain physiological activity which is influenced by the social environment in which the activity changes occur, and the mood status, temperament and background of the person ‘feeling’ these physiological changes. It will be evident from all of these different definitions how complex fatigue is an ‘entity’ / functional process, and how hard it is for even experts in the field to describe to someone asking about it what fatigue is, let alone understand it from a research perspective.

A number of different physical factors have been related to the development of the sensation of fatigue we all ‘feel’ during our daily life. During physical activity, it has been proposed that changes in the body related to the increased requirements of the physical exertion being performed cause the sensation of fatigue to ‘arise’. These include increased heart rate, increased respiratory rate, increased acid ‘build up’ in the muscles, reduced blood glucose or muscle or liver glycogen, or temperature changes in the body, particularly increased heat build-up – though for each study that shows one of these factors is ‘causal’ of the sensation of fatigue, one can find a study that shows that each of these specific factors is not related to the development of the sensation of fatigue. It has also been proposed that changes in the concentration of substrates in the brain structures associated with physical or mental activity are related to the sensation of fatigue – such as changes in neurotransmitter levels (for example serotonin, acetylcholine, glutamate), or changes in the nutrients supplied to the brain such as glucose, lactate or branched chain amino acids. But, again, for each study whose findings support these hypotheses, there are studies that refute such suggestions. It has also been suggested that a composite ‘aggregation’ of changes in all these body and brain factors may result in the development of the sensation of fatigue, via some brain process or function that ‘valences’ each in a fatigue ‘algorithm’, or via intermediate sensations such as the sensation of breathlessness associated with increased ventilation, the sensation of a ‘pounding’ heart from cardiac output increases, the sensation of being hot and sticky and sweating which result from temperature increases in the body, and / or the sensation of pain in muscles working hard, all of which are themselves ‘aggregated’ by brain structures or mental functions to create the complex sensation we know and describe as fatigue.

Which physical brain structures are involved in the creation of the sensation of fatigue is still not known, and given the complexity of the factors involved in its generation, as described above, large areas of the brain and a number of different brain systems are likely to be involved – the motor cortex as muscle activity is often involved, the sensory cortex as signals from changes in activity in numerous body ‘parts’ and functions are ‘picked up’ and assimilated by the brain, the frontal cortex as cognitive decision making on the validity of these changes and the need for potential changes in activity as a result of this ‘awareness’ of a changed state is required, the hippocampus / amygdala region as the current changes in physiological or mental activity must be ‘valenced’ against prior memories of similar changes in the past in order to make valid ‘sense’ of them as they currently occur, and the brainstem as this is the area where ventilation, heart function and a variety of other ‘basic’ life maintaining functions are primarily controlled, for example, amongst many other potential brain areas. We don’t know how the function of different brain areas is ‘integrated’ to give us the conscious ‘whole’ sensation we ‘feel’, and until we do so, it is difficult to understand how the physical brain structures ‘create’ the sensation of fatigue, let alone the ‘feeling’ of it.

How the mental ‘feeling’ of fatigue is related to these physical body and brain change ‘states’ is also challenging for us research folk to understand. Clearly some ‘change’ in structures, baseline physical values or mental states by whatever induces the fatigue process, be it physical or mental exertion or illness, is required for us to ‘sense’ these and for our brain and mental functions to ‘ascribe’ the sensation of fatigue to these changed states. It has previously been shown that the sensation of fatigue which arises during exercise is related to the distance to be covered, and increases as one gets closer to the finish line. While this sounds obvious, as one would expect the body to become more ‘changed’ as one exercises for a longer period, it has been shown that when folk run at the same pace for either five or ten kilometres, despite their pace being identical in both, at the 4km mark in the 5 km race the rating these folk give for the sensation of fatigue is higher than it is at 4km of the 10 km race, which is ‘impossible’ to explain physiologically, and suggests that folk ‘set’ their perceptual apparatus differently for the 5 and 10 km race, based on how far they have to go (what H-V Ulmer described as teleoanticipation), by changing the ‘gain’ of the relationship between the signals they get from their body depending on how far they plan to go. Two great South African scientists, Professor Ross Tucker of the University of Free State, and Dr Jeroen Swart of the University of Cape Town, have expanded on this by suggesting that there is a perceptual ‘template’ for the sensation of fatigue in the brain, and the sensation of fatigue is ‘created’ in an organized, pre-emptive ‘way’ by mental / cognitive processes in the brain, and the sensation of fatigue is ‘controlled’ by this template depending on the distance and / or duration of a sporting event. If something unexpected happens during an event, like a sudden drop in temperature, or a competitor that goes faster than expected, this will create an unexpected ‘change’ in signals from the body and requirements of the race, and the sensation of fatigue will become more pronounced and greater than what is expected at that point in the race, and one will slow down, or change plans accordingly. Ross and Jeroen’s fascinating work show how complex the mental component of the sensation of fatigue and its ‘creation’ by brain structures is.

There are multiple other factors which are involved in the generation of the sensation of fatigue, or of its modulation. I did my medical PhD (an MD) on chronic fatigue syndrome which developed in athletes who pushed themselves too hard until they eventually physically ‘broke down’ and developed the classical fatigue symptoms associated with chronic fatigue, where they felt fatigue even when not exercising, which was not relieved by prolonged periods of rest. These athletes clearly pushed themselves ‘through’ their fatigue symptoms on a regular basis until they damaged themselves. As one of the pioneer and world-leading experts in the fatigue field, Professor Sam Marcora, has pointed out, one’s ambitions and drives and ‘desire for success’ are a strong indicator both of the level of the symptom of fatigue folk will ‘feel’, and how they resist these symptoms. In these chronically fatigued folk we studied, something in their psychological makeup induced them either to constantly continue exercising despite the symptoms of fatigue, or made them ‘feel’ less sensations of fatigue for the same work-rate (assuming their fitness levels and physical capacity was similar) to most folk who do not experience this syndrome (the vast majority of folk). To make the matter even more complex, these folk with chronic fatigue described severe sensations of fatigue at rest, but when we put them on a treadmill, some of them paradoxically felt less, rather than more, sensations of fatigue when running as compared to resting, and their extreme sensations of fatigue returned (to an even greater degree) in the rest period after they completed the running bout. Furthermore, if one gives stimulants to folk when they exercise, such as caffeine, it appears to reduce the ‘awareness’ of the sensations of fatigue. Sam is doing some interesting work currently looking at the effect of caffeine on attenuating the sensation of fatigue – as did Dr Angus Hunter several years ago – and thereby using it as a ‘tool’ to get folk to exercise more ‘easily’ as they appear to ‘feel’ fatigue less after ingesting caffeine. All this shows again that the sensation of fatigue is both a very complex emotion, and a very ‘labile’ one at that, and can change, and be changed, by both external factors such as these stimulants, and internal factors such as one’s drive or ‘desire’ to resist the sensation of fatigue as they arise, or even ‘block them out’ before they are consciously generated. More research, and very advanced research techniques, will be required for us to clearly understand how and such potential ‘blockages’ of the sensation of fatigue happen, if they indeed occur.

The sensation of fatigue is therefore an immensely complex ‘derivative’ of a number of functions, behaviours, and psychological ‘filters’, and what we finally ‘feel’ as fatigue is ‘more’ than a simple one-to-one description of some underlying change in our physical body and brain that requires adjustment or attenuation. The sensation of fatigue is clearly a protective phenomenon designed to slow us down when we are exercising too hard or too long in a manner that may damage our body, or when we are working too hard or too long and need a ‘time out’, or when the environment one is performing activities of daily living in may be harming one. But there are usually more complex relationships and reasons for the occurrence of the sensation of fatigue than what on the surface may appear to be the case. For example, the increase in work related fatigue I feel is surely related not just to the fact that it is the end of a busy week – it is perhaps likely to be related to a ‘deep’ yearning to be back on holiday, or to the fact that my mind is not ‘hardened’ yet to my routine daily work requirements, or has been ‘softened’ by the holiday period so that now I feel fatigue ‘more’ than is usual. In a few weeks time this will surely be attenuated as the year progresses and my weekly routines, which have been ‘honed’ over many years of work, are re-established, and I will feel the ‘usual’ rather than excessive symptoms of fatigue as always on Thursdays and Fridays. The extreme feeling of fatigue I felt during the very hot December month may also be related to some subconscious ‘perception’ that my current living environment is perhaps not optimal for me lifestyle wise for a long term living basis, and this ‘valenced’ how I perceived the environment as one of extreme heat and therefore extreme (and greater than expected) fatigue last month. And that I am ‘enjoying’ the sensations of fatigue I feel when exercising may mean that I am perhaps not pushing my exercise bouts as hard as I could, and need to go harder, or that my mind and body is setting a pace that feels enjoyable both so I continue doing it, or to protect me from a potential heart attack if I go harder. All of these may be the case, or equally, all of these could be mere speculation – the science folk in the area of fatigue have a big mountain to climb, and many more hours in the lab, before we more fully understand the complex emotion which the sensation of fatigue is, and how and from where it arises and is controlled.

A time may come when Sam Marcora and other excellent research colleagues like him find the ‘magic bullet’ that will ‘banish’ the sensation of fatigue, and we will be able to work harder and exercise longer because of it. But then would the cold drink after exercise taste so good, or the feeling of accomplishment one gets at the end of a long exercise bout as a result of resisting the sensation of fatigue long enough to achieve one’s goals for the particular exercise bout one has just completed still occur? This is something to ponder on, when fatigued, as I am now after two hours of writing, as I sip my cup of coffee, and wait for my ‘energy’ to return so I can begin the next task of a routine Sunday, whether it be cycling with the kids, walking the dog, or any other fatigue-removing activity as I prepare for the next fatiguing cycle which is the work and sport week ahead!


Control of Movement And Action – Technically Challenging Conceptual Requirements And Exquisite Control Mechanisms Underpin Even Lifting Up Your Coffee Cup

During the Christmas break we stayed in Durban with my great old friend James Adrain, and each morning I would as usual wake around 5.00 am and make a cup of coffee and sit outside in his beautiful garden and reflect on life and its meaning before the rest of the team awoke and we set off on our daily morning bike-ride. One morning I accidentally bumped my empty coffee mug, and as it headed to the floor, my hand involuntarily reached out and grabbed it, saving it just before it hit the ground. During the holiday I also enjoyed watching a bit of sport on the TV in the afternoons to relax after the day’s festivities, and once briefly saw highlights of the World Darts Championship, which was on the go, and was struck by how the folk competing seemed with such ease, and with apparent similar arm movements when throwing each dart, to be able to hit almost exactly what they were aiming for, usually the triple twenty. When I got back home, I picked up from Twitter a fascinating article on movement control posted by one of Sport Sciences most pre-eminent biomechanics researchers, Dr Paul Glazier, written by a group of movement control scientists including Professor Mark Latash, who I regard as one of the foremost innovative thinkers in the field of the last few decades. All of these got me thinking about movement control, and what must be exquisite control mechanisms in the brain and body which allowed me to in an instant plan and enact a movement strategy which allowed me to grab the falling mug before it hit the ground, and allowed the Darts Championship competitors to guide their darts, using their arm muscles, with such accuracy to such a small target a fair distance away from them.

Due to the work over the last few centuries of a number of great movement control researchers, neurophysiologists, neuroscientists, biomechanists and anatomists, we know a fair bit about the anatomical structures which regulate movement in the different muscles of the body. In the brain, the motor cortex is the area where command outflow to the different muscles is directly activated, and one of the highlights of my research career was when I first used transcranial magnetic stimulation, working with my great friend and colleague Dr Bernhard Voller, where we able to make muscles in the arms and leg twitch by ‘firing’ magnetic impulses into the motor cortex region of the brain by holding an electromagnetic device over the scalp above this brain region. The ‘commands for action’ from the motor cortex travel to the individual muscles via motor nerves, using electrical impulses in which the command ‘code’ is supplied to the muscle by trains of impulses of varying frequency and duration. At the level of the individual muscles, the electrical impulses induce a series of biochemical events in and around the individual muscle fibres which cause them to contract in an ‘all or none’ way, and with the correct requested amount of force output from the muscle fibre which has been ‘ordered’ by the motor cortex in response to behavioural requirements initiated in brain areas ‘upstream’ from the motor cortex, such as one’s eyes picking up a falling cup and ‘ordering’ reactive motor commands to catch the cup. So while even though the pathway structures from the brain to the muscle fibres are more complex than I have described here – there are a whole host of ‘ancient’ motor pathways from ‘lower’ brainstem areas of the brain which also travel to the muscle or synapse with the outgoing motor pathways, whose functions appear to be redundant to the main motor pathways and may still exist as a relic from the days before our cortical ‘higher’ brain structures developed – we do know a fair bit about the individual motor control pathways, and how they structurally operate and how nerve impulses pass from the brain to the muscles of the body.

However, like everything in life, things are more complex than what is described above, as even a simple action like reaching for a cup, or throwing a dart, requires numerous different muscles to fire either synchronously and / or synergistically, and indeed just about every muscle in the body has to alter its firing pattern to allow the body to move, the arm to stretch out, the legs to stabilize the moving body, and the trunk to sway towards the falling cup in order to catch it. Furthermore, each muscle itself has thousands of different muscle fibres, all of which need to be controlled by an organized ‘pattern’ of firing to even the single whole muscle. This means that there needs to be a coordinated pattern of movement of a number of different muscles and the muscle fibres in each of them, and we still have no idea how the ‘plan’ or ‘map’ for each of these complex pattern of movement occurs, where it is stored in the brain (as what must be a complex algorithm of both spatial and temporal characteristics to recruit not only the correct muscles, but also the correct sequence of their firing from a timing perspective to allow co-ordinated movement), and how a specific plan is ‘chosen’ by the brain as the correct one from what must be thousands of other complex movement plans. To make things even more challenging, it has been shown that each time one performs a repetitive movement, such as throwing a dart, different synergies of muscles and arm movement actions are used each time one throws the dart, even if to the ‘naked’ eye it appears that the movement of the arm and fingers of the individual throwing the dart seems identical each time it is thrown.

Perhaps the scientist that has made the most progress in solving these hugely complex and still not well understood control process has been Nikolai Bernstein, a Russian scientist working out of Moscow between the 1920’s and 1960’s, and whose work was not well known outside of Russia because of the ‘Iron Curtain’ (and perhaps Western scientific arrogance) until a few decades ago, when research folk like Mark Latash (who I regard as the modern day equivalent of Bernstein both intellectually and academically) translated his work into English and published it as books and monographs. Bernstein was instructed in the 1920’s to study movement during manual labour in order to enhance worker productivity under the instruction of the communist leaders of Russia during that notorious epoch of state control of all aspects of life. Using cyclographic techniques (a type of cinematography) he filmed workers performing manual tasks such as hitting nails with hammers or using chisels, and came to two astonishing conclusions / developed two movement control theories which are astonishingly brilliant (actually he developed quite a few more than the two described here), and if he was alive and living in a Western country these would or should have surely lead to him getting a Nobel prize for his work. The first thing he realized was that all motor activity is based on ‘modelling of the future’. In other words, each significant motor act is a solution (or attempt at one) of a specific problem which needs physical action, whether hitting a nail with a hammer, or throwing a dart at a specific area of a dartboard, or catching a falling coffee cup. The act which is required, which in effect is the mechanism through which an organism is trying to achieve some behavioural requirement, is something which is not yet, but is ‘due to be brought about’. Bernstein suggested that the problem of motor control and action therefore is that all movement is the reflection or model of future requirements (somehow coded in the brain), and a vitally useful or significant action cannot either be programmed or accomplished if the brain has not created pre-requisite directives in the forms of ‘maps’ of the future requirements which are ‘lodged’ somewhere in the brain. So all movement is in response to ‘intent’, and for each ‘intent’ a map of motor movements which would solve this ‘intent’ is required, a concept which is hard enough to get one’s mind around understanding, let alone working out how the brain achieves this or how these ‘maps’ are stored and chosen.

The second of Bernstein’s great observations was what is known as motor redundancy (Mark Latash has recently suggested that redundancy is the wrong word, and it should have been known as motor abundancy), or the ‘inverse dynamics problem’ of movement. When looking at the movement of the workers hitting a nail with a hammer, he noticed that despite them always hitting the nail successfully, the trajectory of the hammer through the air was always different, despite the final outcome always being similar. He realized that each time the hammer was used, a different combination of arm motion ‘patterns’ was used to get the hammer from its initial start place to when it hit the nail. Further work showed that each different muscle in the arm was activated differently each time the hammer was guided through the air to the nail, and each joint moved differently for each hammer movement too. This was quite a mind-boggling observation, as it meant that each time the brain ‘instructed’ the muscles to fire in order to control the movement of the hammer, it chose a different ‘pattern’ or ‘map’ of coordinative muscle activation of the different muscles and joints in the arm holding the hammer for each hammer strike of the nail, and that for each planned movement therefore, thousands of different ‘patterns’ or ‘maps’ of coordinated muscle movement must be stored, or at least available to the brain, and a different one appears to be chosen each time the same repetitive action is performed. Bernstein therefore realized that there is a redundancy, or abundancy, of ‘choice’ of movement strategies available to the brain for each movement, let alone complex movement involving multiple body parts or limbs. From an intelligent control systems concept, this is difficult to get one’s head around, and how the ‘choice’ of ‘maps’ is made each time a person performs a movement is still a complete mystery to movement control researchers.

Interestingly, one would think that with training, one would reach a situation where there would be less motor variability, and a more uniform pattern of movement when performing a specific task. But, in contrast, the opposite appears to occur, and the variability of individual muscle and joint actions in each repetitive movement appears to maintain or even increase this variability with training, perhaps as a fatigue regulating mechanism to prevent the possibility of injury occurring from potentially over-using a preferentially recruited single muscle or muscle group. Furthermore, the opposite appears to happen after injury or illness, and after for example one suffers a stroke or a limb ligament or muscle tear, the pattern of movements ‘chosen’ by the brain, or available to be chosen, appears to be reduced, and similar movement patterns occur during repetitive muscle movement after such an injury, which would also be counter-intuitive in many ways, and is perhaps related to some loss of ‘choice’ function associated with injury or brain damage, rather than damage to the muscles per se, though more work is needed to understand this conceptually, let alone functionally.

So, therefore, the simple actions which make up most of our daily life, appear to be underpinned by movement control mechanisms of the most astonishing complexity, which we do not understand well (and I have not even mentioned the also complex afferent sensory components of the movement control process which adjust / correct non-ballistic movement). My reaction to the cup falling and me catching it was firstly a sense of pleasure that despite my advancing age and associated physical deterioration I still ‘had’ the capacity to respond in an instant and that perhaps the old physical ‘vehicle’ – namely my body – through which all my drives and dreams are operationalized / effected (as Freud nicely put it) still works relatively okay, at least when a ‘crisis’ occurs such as the cup falling. Secondly I felt the awe I have felt at many different times in my career as a systems control researcher at what a brilliant ‘instrument’ our brains and bodies as a combination are, and whatever or whoever ‘created’ us in this way made something special. The level of exquisite control pathways, the capacity for and of redundancy available to us for each movement, the intellectual capacity from just a movement control perspective our brain possesses (before we start talking of even more complex phenomena such as memory storage, emotional qualia, and the mechanisms underpinning conscious perception) are staggering to behold and be aware of. Equally, when one sees each darts player, or any athlete performing their task so well for our enjoyment and their success (whether darts players can be called ‘athletes’ is for another discussion perhaps), it is astonishing that all their practice has made their movement patterns potentially more rather than less variable, and that this variability, rather than creating ‘malfunction’, creates movement success and optimizes task outcome capacity and performance.

It is in those moments as I had when sitting in a beautiful garden in Durban in the early morning of a holiday period, reflecting on one’s success in catching a coffee cup, that creates a sense of wonder of the life we have and live, and what a thing of wonder our body is, with its many still mystical, complex, mostly concealed control processes and pathways regulating even our simple movements and daily tasks. In each movement we perform are concealed a prior need or desire, potentially countless maps of prospective plans for it, and millions of ways it can be actualized, from which our brain chooses one specific mechanism and process. There is surely magic in life not just all around but in us too, that us scientist folk battle so hard to try and understand, but which are to date still impenetrable in all their brilliance and beauty. So with a sigh, I stood up from the table, said goodbye to the beautiful garden and great friends in Durban, and the relaxing holidays, and returned to the laboratory at the start of the year to try and work it all out again, yet knowing that probably I will be back in the same place next year, reflecting on the same mysteries, with the same awe of what has been created in us, and surely still will no further to understanding, and will still be pondering, how to work it all out – though next year I will be sure to be a bit more careful where I place my finished coffee cup!


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