Author Archives: JKwasniak

Does it ring true?

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I make a point of not commenting on research into medical and psychological conditions. However, I am dyslexic and feel able to comment on research into that specific condition. I recognize that there are probably many types, levels and causes of dyslexia and so my reaction might not be the same as others. But I still automatically judge the research by ‘does it feel like it is right in my case?’

Several theories have fit with my experience of dyslexia. The idea that there is a problem with the corpus callosum, the nerves that connect the two hemispheres, in the region where the sound processing is done so that the left and right hemispheres do not properly cooperate for auditory information. This fits with my brother’s cleft pallate and more severe dyslexia and with my high pallate. It might explain the lack of consciousness of what I am going to say that often happens to me. (It has only been on rare occasions that I have disagreed with that I have said.) I am left-handed and perhaps am not conscious of what the other hemisphere is preparing to say due to a lack of communication at some area along the corpus callosum.

Another theory points to a fault in the dorsal/ventral streams. This idea is that sensory information leaves the primary sensory areas via two paths called the dorsal and ventral streams, also called the ‘where/how’ and the ‘what’ streams. The dorsal (where) path leads to motor speech areas, is very fast, and not very conscious. The ventral (what) path leads to more cognitive areas where auditory information is converted into semantic information, is slower, and more conscious. These streams interact in some ways – they both map phonemes but in two different maps and those maps need to be consistent with one another. We need to recognize a phoneme and we need to speak a phoneme. Dyslexics appear to have great difficulty consciously recognizing individual phonemes. They also appear to have difficulty with very short phonemes in particular. This appears to have something to do with a lack of communication between the streams.

Reasonable oral skill (as opposed to written) is possible without phonological awareness by dealing with syllables as entities that are not divided into individual phonemes. The vowel in the syllable is modified by the consonants that proceed or follow it. So the a in bat is different than the a in cap. It is not necessary to recognize the individual b, t, c or p in order to recognize the two words and produce them in speech because the short consonants modify the vowel. This also rings true to me – it is like it feels. The inability to consciously recognize things as separate if they are close together and very poor reflex times also indicate this time problem with short consonants. It is odd, but I find it hard to explain to people how it is to hear a syllable clearly but not hear its components. I seems such a simple obvious perception to me, a single indivisible sound.

Neither of these theories explain the symptoms of mixing up left and right, clockwise and counterclockwise, confusing something with its mirror image and the ‘was’ and ‘saw’ problem. Nor do they explain the slight lag between knowing something was said and hearing what it was.

Theories that have to do with vision or with short-term memory do not seem to apply to me. Although I have to admit that I am not sure what a bad short-term memory would feel like. I certainly have an excellent long-term memory.

Recently there has appear a paper with a new theory. (Perrachione, Del Tufo, Winter, Murtagh, Cyr, Chang, Halverson, Ghosh, Christodoulou, Gabrieli; Dysfunction of Rapid Neural Adaptation in Dyslexia ; Neuron 92, 1383–1397, December 2016) They looked at perceptual adaption in dyslexics and non-dyslexics. Perceptual adaption is the attenuation in perceptual processing of repetitive stimuli. So for example if the same voice says a list of words, there is less activity in parts of the brain than if a different voice delivers each word. The brain has adapted to the voice and that makes processing easier. They measured the adaptation using fMRI and used procedures featuring spoken words, written words, objects and faces with adult subjects and children just starting to read. Always the adaption was weaker for dyslexics then for controls. Also the differences were in the areas involved in processing the particular type of stimulus (such as in visual areas for visual stimuli). The amount of adaptation in these areas correlated with the level of reading skill of the dyslexic. The research supports the idea that dysfunction in neural adaptation may be and important aspect of dyslexia.

Here is part of their conclusion:

“Dyslexia is a specific impairment in developing typical reading abilities. Correspondingly, structural and functional disruptions to the network of brain areas known to support reading are consistently observed in dyslexia. However, these observations confound cause and consequence, especially since reading is a cultural invention that must make use of existing circuitry evolved for other purposes. In this way, differences between brains that exert more subtle influences on non-reading behaviors are likely to be the culprit in a cascade of perceptual and mnemonic challenges that interfere with the development of typical reading abilities. Recent research has begun to elucidate a cluster of behaviorally distinct, but potentially physiologically related, impairments that are evinced by individuals with reading difficulties and observable in their brains. Through this collection of neural signatures—including unstable neural representations, diminished top-down control, susceptibility to noise, and inability to construct robust short-term perceptual representations—we are beginning to see that reading impairments can arise from general dysfunction in the processes supported by rapid neural adaptation.”

Does the theory ring true? It certainly fits with the feeling that the problem is wider than just language. I have to say that I have always found it difficult to mimic other people’s speech and that would fit with a weak adaptation. The theory does not seem impossible to me but it also does not seem to fit closely to how I feel about being dyslexic. I feel a kind of wall between what I hear and written language; I have never felt that I have overcome the wall; but I have felt that I worked around it.

I have to give the paper respect for the convincing data even if it does not seem to be the whole story. The picture may be about some aspect of the dyslexic developmental fault but not actually have much to do with the main symptom, difficulty with phoneme awareness.

Time travel is not uniquely human

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There are constantly statements about what abilities humans have that are unique. One of these is mental time travel. Decades ago Tulving put forward the notion of episodic memory and at the same time stated his opinion that it was unique to humans and that animals do not have episodic memory or a conscious experience of remembering. Suddendorf and Corballis put forward the notion of mental time travel: “the human ability to travel mentally in time constitutes a discontinuity between ourselves and other animals”. Lately Corballis has changed his mind: “Mental time travel has neurophysiology underpinnings that go far back in evolution, and may not be as some (including myself) have claimed, unique to humans.” Other animals may experience remembering specific events and may experience the planning of future events. In fact, I would find it difficult to explain their behavior if they did not have these abilities.

Imaging the old grandmother elephant leading her family to the bones of dead relatives, where they can touch and look at bones of specific dead loved ones. We know elephants are conscious even self-conscious, have theory of mind, have long memories, know and can navigate huge territories and know individual elephants that are not part of their group. I find it very difficult to imagine that when they touch the bones they have come to visit, they are not experiencing vivid memories of their dead relatives.

Time travel has been indicated in rats, pigeons, jays and dolphins but without convincing all critics. Now another study is even more convincing. (Gema Martin-Ordas, Dorthe Berntsen, Josep Call; Memory for Distant Past Events in Chimpanzees and Orangutans; Current Biology, Volume 23, Issue 15, p1438–1441, 2013) Here is the abstract:

Determining the memory systems that support nonhuman animals’ capacity to remember distant past events is currently the focus an intense research effort and a lively debate. Comparative psychology has largely adopted Tulving’s framework by focusing on whether animals remember what-where-when something happened (i.e., episodic-like memory). However, apes have also been reported to recall other episodic components after single-trial exposures. Using a new experimental paradigm we show that chimpanzees and orangutans recalled a tool-finding event that happened four times 3 years earlier (experiment 1) and a tool-finding unique event that happened once 2 weeks earlier (experiment 2). Subjects were able to distinguish these events from other tool-finding events, which indicates binding of relevant temporal-spatial components. Like in human involuntary autobiographical memory, a cued, associative retrieval process triggered apes’ memories: when presented with a particular setup, subjects instantaneously remembered not only where to search for the tools (experiment 1), but also the location of the tool seen only once (experiment 2). The complex nature of the events retrieved, the unexpected and fast retrieval, the long retention intervals involved, and the detection of binding strongly suggest that chimpanzees and orangutans’ memories for past events mirror some of the features of human autobiographical memory.

It seems unscientific to assume the answer before asking the question. Why was it assumed that animals did not feel? Then why assume that they did not think? Then, anyway they were not conscious, right? And now that they cannot consciously remember personal events? There was tool using, then tool making, and then serial tool use, all disproved. The only thing that has come close is that animals have no language ability. Even that may be over turned by whales. This drive to find human uniqueness and the stubbornness in defending it, is unbecoming to science. It is not creationism – but somehow it has a tiny bit of the same odour. Science should be looking at why animals (including humans) have a episodic memory, how it helps them think, plan, react and not whether it has some mystical ‘autonoetic’ insight to its conscious experience in humans but not other animals.

New look at self-control

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Much of the time, our model of reality is viewed from the perspective of ourselves, right now. The notion of Theory of Mind (ToM) is that to a certain extent we can instead take the perspective of another person. We can metaphorically walk in their shoes. This ability seems to reside in the posterior temporo-parietal junction (pTPJ). This is also the location involved in prosocial behaviour. A recent paper (Soutschek, Ruff, Strombach, Kalenscher, Tobler; Boutrain stimulation reveals crucial role of overcoming self-centeredness in self-control; Science Advances, Oct 2016, Vol. 2, no. 10) finds this area is also involved in controlling impulses to take immediate rewards, rather than wait for greater rewards in future.

The researchers used disruptive transcranial magnetic stimulation (TMS) to shut down the junction and then tested for prosocial vs selfish behavior in a sharing money game, the ability to recognize what another person could see (extent of ToM), and the ability to show self-control to achieve a larger reward. These measures appeared to move together, implying that they might share the same mechanism, most likely that mechanism is a switch between the perspective of the current self and the perspective of another, either another person or the self at another time. This fits with previous findings by others that selfishness and impulsiveness appear to go together in many people.

The paper notes that the frontal lobe is also involved in self-control and discusses how the two areas might cooperate in controlling impulsiveness.

Here is their abstract:

Neurobiological models of self-control predominantly focus on the role of prefrontal brain mechanisms involved in emotion regulation and impulse control. We provide evidence for an entirely different neural mechanism that promotes self-control by overcoming bias for the present self, a mechanism previously thought to be mainly important for interpersonal decision-making. In two separate studies, we show that disruptive transcranial magnetic stimulation (TMS) of the temporo-parietal junction—a brain region involved in overcoming one’s self-centered perspective—increases the discounting of delayed and prosocial rewards. This effect of TMS on temporal and social discounting is accompanied by deficits in perspective-taking and does not reflect altered spatial reorienting and number recognition. Our findings substantiate a fundamental commonality between the domains of self-control and social decision-making and highlight a novel aspect of the neurocognitive processes involved in self-control.

So when the marshmallow test is quoted as showing that children with greater self-control end up being more successful adults, it could be down to more than self-control. They probably also are more prosocial, understand others better and are less selfish.

local or not

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A recent press release describes a paper ( T. A. Engel, N. A. Steinmetz, M. A. Gieselmann, A. Thiele, T. Moore, K. Boahen. Selective modulation of cortical state during spatial attention. Science, 2016; 354 (6316): 1140 DOI: 10.1126/science.aag1420 ) on the neural activity during awake attention. Here is the abstract:

Neocortical activity is permeated with endogenously generated fluctuations, but how these dynamics affect goal-directed behavior remains a mystery. We found that ensemble neural activity in primate visual cortex spontaneously fluctuated between phases of vigorous (On) and faint (Off) spiking synchronously across cortical layers. These On-Off dynamics, reflecting global changes in cortical state, were also modulated at a local scale during selective attention. Moreover, the momentary phase of local ensemble activity predicted behavioral performance. Our results show that cortical state is controlled locally within a cortical map according to cognitive demands and reveal the impact of these local changes in cortical state on goal-directed behavior.

I find the techniques and the results very interesting. However, I have trouble with the idea that attention has a purely cortical mechanism. Why are the fluctuations in activity said to be endogenously generate? Why is the cortical state controlled locally within a cortical map according to cognitive demands and reveal the impact of these local changes in cortical state on goal-directed behavior? The cortex is not isolated from the rest of the brain. To say some effect is locally generated in the cortex would required showing that the activity level was not affected by the thalamus and associated parts of the brain. The back and forth between cortical columns and the thalamus is the key to cortical function and a requirement for attention, consciousness and wakefulness. This is not a new idea but has been around for a long time. Why does this study not just ignore it, but deny it?

The conclusion to a paper (Sallmann and Kastner, Cognitive and Perceptual Functions of the Visual Thalamus Neuron. 2011 Jul 28; 71(2): 209–223) outlines some signaling between various parts of the thalamus and the cortex.

The overall evidence that has emerged during recent years suggests that the visual thalamus serves a fundamental function in regulating information transmission to the cortex and between cortical areas according to behavioral context. Selective attention and visual awareness have been shown to modulate LGN (thalamus lateral geniculate nucleus) activity, thus indicating that the LGN filters visual information before it reaches the cortex. Behavioral context appears to even more strongly modulate pulvinar activity and, due to its connectivity, the pulvinar (a part of the thalamus) is well-positioned to influence feedforward and feedback information transmission between cortical areas. Because the TRN provides strong inhibitory input to both the LGN and pulvinar, the TRN (thalamic reticular nucleus) may control and coordinate the information transmitted along both retino-cortical and cortico-cortical pathways.

Parasuraman and Davis in Varieties of Attention, page 236, described the networks involved in attention as long ago as 1984.

Three interacting networks mediating different aspects of attention: (1) a posterior attention system comprising parietal cortex, superior colliculus (a midbrain area), and pulvinar(thalamus area) that is concerned was spatial attention; (2) anterior system centered on the anterior cingulate in the medial frontal lobe that mediates target detection and executive control; (3) a vigilance system consisting of the right frontal lobe and brainstem nuclei, principally the noradrenergic locus coerulus (LC).

The brain is a functioning whole not a group of completely independent parts. As the Engel group do not seem to even address the question of involvement of regions of the brain other then the cortex – how can they state that the activity level of a column is locally produced?

 

Notice

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i have just lost my husband and will not have time or inclination to post for a while. I will be back in a a few months.

Beta waves

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Judith Copithorne image

Brain waves are measured for many reasons and they have been linked to various brain activities. But very little is known about how they arise. Are they the result or the cause of the activities they are associated with? How exactly are they produced at a cellular or network level? We know little about these waves.

One type of wave, beta waves (18-25 Hz) are associated with consciousness and alertness. In the motor cortex they are found when muscle contractions are isotonic (contractions that do not produce movement) but are absent just prior and during movement. They are increased during sensory feedback to static motor control and when movement is resisted or voluntarily suppressed. In the frontal cortex the beta waves are found during attention to cognitive tasks directed to the outside world. They are found in alert attentive states, problem solving, judgment, decision making, and concentration. The more involved the cognitive activity the faster the beta waves.

ScienceDaily reports a press release from Brown University on the work of Stephanie Jones and team, who are attempting to understand how beta waves arise. (here) Three types of study are used: MEG recordings, computer models, and implanted electrodes in animals.

The MEG recordings from the somatosensory cortex (sense of touch) and the inferior frontal cortex (higher cognition) showed a very distinct form for the beta waves, “they lasted at most a mere 150 milliseconds and had a characteristic wave shape, featuring a large, steep valley in the middle of the wave.” This wave form was recreated in a computer model of the layers of the cortex. “They found that they could closely replicate the shape of the beta waves in the model by delivering two kinds of excitatory synaptic stimulation to distinct layers in the cortical columns of cells: one that was weak and broad in duration to the lower layers, contacting spiny dendrites on the pyramidal neurons close to the cell body; and another that was stronger and briefer, lasting 50 milliseconds (i.e., one beta period), to the upper layers, contacting dendrites farther away from the cell body. The strong distal drive created the valley in the waveform that determined the beta frequency. Meanwhile they tried to model other hypotheses about how beta waves emerge, but found those unsuccessful.” The model was tested in mice and rhesus monkeys with implanted electrodes and was supported.

Where do the signals come from that drive the pyramidal neurons? The thalamus is a reasonable guess at the source. Thalamo-cortex-thalamus feedback loop makes those very contacts of the thalamus axons within the cortex layers. The thalamus is known to have signals with 50 millisecond duration. All of the sensory and motor information that enters the cortex (except smell) comes though the thalamus. It regulates consciousness, alertness and sleep. It is involved in processing sensory input and voluntary motor control. It has a hand in language and some types of memory.

The team is continuing their study. “With a new biophysical theory of how the waves emerge, the researchers hope the field can now investigate beta rhythms affect or merely reflect behavior and disease. Jones’s team in collaboration with Professor of neuroscience Christopher Moore at Brown is now testing predictions from the theory that beta may decrease sensory or motor information processing functions in the brain. New hypotheses are that the inputs that create beta may also stimulate inhibitory neurons in the top layers of the cortex, or that they may may saturate the activity of the pyramidal neurons, thereby reducing their ability to process information; or that the thalamic bursts that give rise to beta occupy the thalamus to the point where it doesn’t pass information along to the cortex.”

It seems very clear that understanding of overall brain function will depend on understanding the events at a cellular/circuit level; and that those processes in the cortex will not be understood without including other regions like the thalamus in the models.

Fighting Libet’s experiment

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A post in Science of Us in Feb, by Christian Jarrett, reviews the Libet experiment and recent attempts to overturn the implications of it. (http://nymag/scienceofus/2016/02/a-neuroscience-finding-on-free-will.html ) I find the struggle to reverse Libet’s finding to be the result of a mistaken way of viewing thought. An enormous amount of effort has gone into failed attempts to show this experiment was flawed over the last 30 years. Why are the implications so hard for people to accept?

Here is the first bit of Jarrett’s article (underlining is mine).

“Back in the 1980s, the American scientist Benjamin Libet made a surprising discovery that appeared to rock the foundations of what it means to be human. He recorded people’s brain waves as they made spontaneous finger movements while looking at a clock, with the participants telling researchers the time at which they decided to waggle their fingers. Libet’s revolutionary finding was that the timing of these conscious decisions was consistently preceded by several hundred milliseconds of background preparatory brain activity (known technically as “the readiness potential”).

The implication was that the decision to move was made nonconsciously, and that the subjective feeling of having made this decision is tagged on afterward. In other words, the results implied that free will as we know it is an illusion — after all, how can our conscious decisions be truly free if they come after the brain has already started preparing for them?

For years, various research teams have tried to pick holes in Libet’s original research. It’s been pointed out, for example, that it’s pretty tricky for people to accurately report the time that they made their conscious decision. But, until recently, the broad implications of the finding have weathered these criticisms, at least in the eyes of many hard-nosed neuroscientists, and over the last decade or so his basic result has been replicated and built upon with ever more advanced methods such as fMRI and the direct recording of neuronal activity using implanted electrodes.

These studies all point in the same, troubling direction: We don’t really have free will. In fact, until recently, many neuroscientists would have said any decision you made was not truly free but actually determined by neural processes outside of your conscious control.”

That is the stumbling block: ‘neural processes outside of conscious control’. That is what some scientists are fighting so hard not to lose. The whole notion of what free will is rests on how we view who we are, what our consciousness is, and how control works.

When we think of who we are, we cannot separate self from non-self within our bodies. We are not really divided at the neck, or between the upper and lower parts of the brain, or between different ‘minds’ co-existing in one skull. This idea of two separate minds, that was inherited from Freud and others, has not been demonstrated to be true. It has not been shown that we have two distinct thinking minds that are somehow separate. Thinking appears to be a complex, widespread but interconnected and unified affair. Whether a particular thought process becomes conscious or remains non-conscious does not depend on the basic process of thought.

There is every reason to reject the notion of a separate conscious mind that thinks in a ‘conscious’ manner to produce conscious thoughts. We are aware of thoughts (some thoughts) but we are not aware of the mechanisms that produced the thoughts. We do not metaphorically hear the gears of thought production grinding. We are simply not aware of how thought happens. Consciousness is a form of awareness and probably not much more. There is awareness of some things that go on in the brain but not of all things or even the bulk of things.

So why are some thoughts made conscious while others aren’t? A good guess is that consciousness gives a remembered experience, an episodic memory, or at least the material for such memories. With memories of our actions, it would be important information to remember whether the action was our doing or just happened to us, whether it was accidental or intended, whether it was a choice or coerced, carefully planned or an automatic habit and so on. These pieces of information are important to save and so would be incorporated into conscious events. We need that information to learn from experience. Just because the feeling of having an intent, an urge and then an execution of an action is there in our conscious awareness does not mean that they were a form of conscious control. They are there as important parts of the event that consciousness is recording.

We can still control our actions, and we still can be aware of controlling our actions, but that does not mean that our awareness is producing the control that we are aware of. Consciousness does not produce the tree that I am aware of – it just produces the awareness. And you are just you, and not your awareness of you. There is reality and there are models of reality; there is territory and there are maps of the territory; there is an original and there are copies of the original. There is you and there is your awareness of you. You make decisions (with neural activity) but your awareness of a decisions is not the same as making it.

I personally find it a little difficult to understand why this idea of a conscious mind as opposed to a conscious awareness is so strong and indestructible an idea to most people. I cannot remember exactly how or when (it was a gradual process) but some time in my late teens, over 50 years ago, my consciousness became a flickering imperfect movie screen and not a thinking mind. So “determined by neural processes outside of conscious control” is obvious because there is no such thing as conscious control and what is more, it is a comforting rather than alarming viewpoint.

I am assuming that the current experiments with showing ‘free won’t’ will not turn out to be any more robust than the attempts to show free will. We shall see.

Why sleep

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It would be surprising if there were a single function for sleep, but there are often articles implying that the mystery is solved and THE reason for sleep has been found. Recently there was one in the New Scientist which prompted my post (https://www.newscientist.com/article/2096921-mystery-of-what-sleep-does-to-our-brains-may-finally-be-solved/).

We can look logically at reasons why we sleep. For any biological behaviour or process, there can be a spectrum of causes. At the one end of the spectrum are the ultimate causes – the evolutionary reason, the function being carried out, and the ‘why’. At the other end are the proximate causes – the individual immediate cause, the trigger, and the ‘how’.

The thing that seems the most distance and universal ultimate cause is probably that it is evolutionarily difficult to be well fitted to two dissimilar niches at the same time. There are animals that are active in the day and adapted to that; they hid and conserve their energy at night because they are not adapted to night. Or an animal can be adapted to night and hid in the day. This idea applies to animals that hibernate through a cold season every year to which they are not well adapted. There are animals that go dormant in dry seasons and are active when it is wet. It would be a good bet that all other functions of sleep are built on this mechanism of being inactive during recurring periods. Sleep is widespread amongst animals.

If there is an inactive time, that is the time to do all the things that cannot be done easily when active. Growth and repair would be immensely easier during rest. Imagine growing new muscle cells in a walking leg – much easier to wait until the leg is not moving. Growth and repair is best done on all the organs when they are just ticking over at most. This would include any maintenance needed in the brain.

These ultimate causes produce, during evolution, a proximate mechanism: an oscillating function that produces drowsiness and than sleep and followed by awakening and activity. Hormones and signals can work this rhythm without triggers, but do use light and darkness to get the timing right. The mechanism also affects the working of the body to make it suitable for growth and repair – the temperature, heart and breathing rates and many hidden levels have different sleep and wake settings. This sort of mechanism causes sleep but it is the ‘how’ of sleep not the ‘why’.

The brain is a complex organ with many functions. It is not a simple concept to say that the brain is inactive, resting and recuperating. There may be many processes in the brain taking advantage of sleep; there are a number of different types of sleep which obviously have different functions.

One function that has been investigated is waste removal. During parts of sleep some of the brain cells become physically smaller and this allow the movement of liquid through the brain, clearing out waste. It probably would interfere with the working of the brain to have cells temporarily lose volume – better to do this during sleep.

Another function that sleep houses is REM phase/dreaming. Dreaming is not completely understood but it is clearly needed for the successful integration of new memories into the web of established memories in the cortex. In this process the memories seem to be partially activated and re-experienced in combination with previous memories. For this process to be safe (without sleep walking or worse) the brain disconnects the possibility of skeletal muscle movement. This paralysis could only be acceptable in the safe inactive state of sleeping.

Another function that is known but not completely understood is the resetting of the brain’s level of activity. This is the one outlined in the NewScientist article. Consider that during the day, there has been continuous firing of neurons as a result of continuous signaling through the synapses of the brain. The synapses that are not used do not lose any strength while the ones that are used increase in strength. We end the day with a very excitable brain. During sleep this is brought down to a lower level to start the next day. All the synapses lose strength so that the new difference between strong ones and weaker ones remains but the overall strength is lower. As a photographic metaphor, it is like lowering the ‘brightness’ while maintaining the ‘contrast’ on a washed out over exposed photo. If this is not done, due to sleep deprivation, then the brain finds it more and more difficult to function. It seems that sleep alternates between strengthening particular synapses and weakening all synapses.

Of course, this is probably only the tip of the iceberg for finding sleep functions in the brain. I would not be surprised at a number of others being identified. There may even be processes that apply to insects but not to humans, as insects can sleep too. That is why an article that implies that there is a single function, THE reason for sleep, and that single reason has finally been found, is annoying. All the causes of, reasons for, functions of sleep are important and unlikely to be all found or understood.

Click bait PR in science

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ScienceDaily reports on a recent paper (Leon Gmeindl, Yu-Chin Chiu, Michael S. Esterman, Adam S. Greenberg, Susan M. Courtney, Steven Yantis. Tracking the will to attend: Cortical activity indexes self-generated, voluntary shifts of attention. Attention, Perception, & Psychophysics, 2016) which looks at the areas in the brain involved in volition. Here is the abstract:

“The neural substrates of volition have long tantalized philosophers and scientists. Over the past few decades, researchers have employed increasingly sophisticated technology to investigate this issue, but many studies have been limited considerably by their reliance on intrusive experimental procedures (e.g., abrupt instructional cues), measures of brain activity contaminated by overt behavior, or introspective self-report techniques of questionable validity. Here, we used multivoxel pattern time-course analysis of functional magnetic resonance imaging data to index voluntary, covert perceptual acts—shifts of visuospatial attention—in the absence of instructional cues, overt behavioral indices, and self-report. We found that these self-generated, voluntary attention shifts were time-locked to activity in the medial superior parietal lobule, supporting the hypothesis that this brain region is engaged in voluntary attentional reconfiguration. Self-generated attention shifts were also time-locked to activity in the basal ganglia, a novel finding that motivates further research into the role of the basal ganglia in acts of volition. Remarkably, prior to self-generated shifts of attention, we observed early and selective increases in the activation of medial frontal (dorsal anterior cingulate) and lateral prefrontal (right middle frontal gyrus) cortex—activity that likely reflects processing related to the intention or preparation to reorient attention. These findings, which extend recent evidence on freely chosen motor movements, suggest that dorsal anterior cingulate and lateral prefrontal cortices play key roles in both overt and covert acts of volition, and may constitute core components of a brain network underlying the will to attend.”

I have not been able to read the original paper but I assume that it is a careful and useful study of how intentions and decisions happen when there is no compulsion involved. It has further evidence of the dorsal anterior cingulate and lateral prefrontal areas being involved in preparation of voluntary action. I assume that the authors do not stoop to ‘click bait’ in the original paper; I assume they use the sort of language that they use in the abstract. The press release put out by Johns Hopkins University is the problem. There are repeated uses of the phrase ‘free will’ and even the phrase “volition, or free will” implying that these words are interchangeable. And ‘free will’ is even used in the title of the press release, which seems like clear click bait to me. There is still debate on whether free will exists and if it does what its mechanism is. Because of this many people would be interested in a scientific paper that deals with free will. Mentioning free will in the PR for the paper is click bait unless the paper actually deals with the subject. Instead the paper seems to be about how decisions prepared and executed. The problem is that the study did not involve any measure of if-when-how the intention or the act was felt in the subject’s consciousness. We do not know what the subjects thought.

There are a number of definitions of free will: in religion it is lack of predestination; in philosophy it is lack of material determination (classic dualism); in jurisprudence it is owning the responsibility for an action (not coerced, accidentally or unconsciously done but in involving conscious intent); in neuroscience it has come to mean a decision taken under conscious control (an action that is started or can be stopped by conscious intent) – very similar to the legal meaning. What the last three have in common is control of intent/execution by conscious thought. Volition is a word without any necessary connection to consciousness. Unless an experiment tracks conscious events as well as other events, it has nothing to say about free will. It can have a great deal to say about volition, decision, intention, motor control, action plans etc. etc. but without involving consciousness, it has absolutely nothing to say about free will. As I said above, I have not been able to read the original paper, but if as I suspect it does not measure or time conscious feelings of intent or execution then its PR is misleading.

Synergy and Modular control

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When we learned the simple overview of the nervous system in grade school, we were taught that the brain sent signals to muscles to contract and that is how we moved. And by brain, we assumed the thinking part up high in the head. But it cannot be so.

A little deer is born and in a very short time is standing and in a little longer is taking its first wobbly step. Within a couple of days it is running and frolicking. Deer are not that special; other animals ‘learn’ to get around very quickly too. Even humans babies, if they are held upright with their feet touching a surface will walk along that surface. In a sense, the spinal cord knows how to walk by lifting and moving forward alternate legs. It does not know how to walk well, but the basics are there. Human babies are slower at managing to get around because they are born at a less developed stage and walking on two legs rather than four is trickier. In all sorts of observations and experiments there is evidence that the ability to walk is innate in the spinal cord and does not require the brain.

The spinal cord has some primitive control modules or muscle synergies. Muscle synergies are present in a number of natural behaviors; they are low-level control networks found in the brain stem and spinal cord that coordinate a group of muscles. They make common movements easier to order up. We have the ‘intent to go over there’ and without any more conscious thought we do it in an automatic way. Now if we had to trigger individual muscles in the right time sequence, it would likely take many hours to get not very far with a number of falls along the way. One could say that we would ‘get the hang of it’ as we did it. But that is saying we would make parts of it automatic (create modules and synergies).

This modularization of motor control is layered. The simplest control is in the spinal cord, but it is modified and adapted to conditions by the brain stem and especially the cerebellum. The cerebellum gets instructions from other parts of the brain and finally these modules within modules are able to execute the simple ‘intention to go over there’.

The synergies in a baby’s spinal cord are an ancient set that is similar of all mammals (probably all land vertebrates). The muscles work in a rhythm where each event triggers the next in a circle. There are two primitives that are involved in human walking that we are born with. One is to bend the leg so that the foot leaves the ground and moves forward then goes back down and straightens. Two is a forward push against the ground by the straight leg. These two complexes of muscle contractions and relaxations are wired so that their action in one leg inhibits their action in the other. When the left leg does one, the right leg cannot do one but can do two. And when the left leg does two, the right cannot do two but can do one. They are also wired so that in each leg it is the end of one that triggers the start of two and the end of two triggers the start of one. It is the same in four legged animals except there is another set of inhibitions between the front and hind legs. At this level it is not very adaptive and can only react to sensory information that comes through the spinal cord from the muscles, joints and skin. Babies cannot use this facility to get around because they do not have the strength to maintain the posture needed with such a large heavy head on such a little body, and more importantly, the spinal cord has no information from the ears about balance. Balance is very important for bipedal walking. The baby must create two other synergies: to react to balance information and to use the hips, back and arms to keep the center of gravity over the legs. In the meantime, when they don’t have the strength, they can crawl using the 4 legged modules.

The cerebellum and brain stem add the control of balance and of pace (there are relative changes to the timing of events when the whole process is sped up). They can correct for uneven ground. They can keep the direction of motion toward a target. But the coordination control of the lower brain is not just direct signals to muscles but uses the synergies built into the spinal cord. And it is much more complex than the action in the spinal cord. In fact, the cerebellum has more neurons that the whole rest of the brain. It manages the modules, timing, adjustments to modules, effects from sensory input and feedback and commands from higher levels of the brain, then packages it all for execution. Another great trick of the cerebellum is to do two things at the same time, say walk and throw a ball. Both may be deep seated modules but there are adjustment to be made where they interfere with one another.

The point I am making here is that although movement seems so easy for us to execute, that is because it is not arranged consciously, or even largely in the cerebral hemispheres. It is modularized so that a simple request in the cerebral cortex goes through layers of calculation and fine-tuning to become individual signals to individual muscles. It is synergy/modularization that gives us this flexible but easy to use system. We are surprised that it is easier to create a program to play chess in the abstract (and win) than it is to program a robot to physically move the pieces and operate the time clock in a game. When we do not understand how something is done, it appears easy. It is a common trap.