Category Archives: consciousness

Ancient Origins – a great book

Ancient Origins – a great book

I have just read a book by Feinberg and Mallatt, The Ancient Origins of Consciousness – How the Brain Created Experience. It may turn out to be one of those classic books that cause a big change in accepted science. They tackle the ‘mystery of consciousness’ in a new way, a very biological way. The book ends with, “a satisfying and complete explanation of primary consciousness requires a confluence of points of view, necessarily including neurobiological, evolutionary, and philosophical arguments, each contributing important answers to the ‘hard question’. Perhaps one reason no one has solved it before is that it requires all three perspectives, including what happened over half a billion years ago.” I assume there will be many who find the book’s theory wanting because of they view neurobiological naturalism is impossible and believe normal science cannot explain consciousness. The authors brand of neurobiological naturalism has three postulates which the book documents:

1. “sensory consciousness can be explained by known neurobiological principles

2. “sensory consciousness is ancient and widespread in the animal kingdom, and diverse neural architectures can create it

3. “the philosophical issues of ontological subjectivity, neuroontological irreducibility, and the ‘hard problem’ can be explained by the nondissociable confluence of neurobiological and adaptive neuroevolutionary events.

The book has changed my ideas in a number of ways. First to fall was my attitude to the idea of ’emergent properties’. I have viewed it as a hedge, a cope-out, and even a way to bring dualism back in disguise. This book describes emergence in a way that makes sense. In a layered hierarchy each layer is created from the layer below but is more complex with novel elements which are labeled as emergent. But the external constraints act primarily on the top layer which constrains the layers beneath it. Thus there is both control and innovation by both bottom-up effects and top-down effects. Yes, this arrangement does need its own name and is a typical situation in living organisms. “In living systems such as the human body, cells constrain their subunits (organelles) to work together, the tissues and organs constrain their cells to cooperate, and the entire body constrains its organs to team up, all to perform the many physiological functions needed for the body to survive. If the constraints were to fail at any level, the body would disassemble and die.” A particular type of layered hierarchy, nested maps of the sensory organs such as the retina, is the basis of consciousness.

My second change of thinking was about the nature of the Cambrian explosion. It had seemed to me that the changes between geological periods were caused by changes to the environment like a meteor strikes which kill off the dominant animals and plants and allowed the others to flourish. But the book makes a case of a change to some animals being the cause and not the result of the abrupt explosion 560 – 520 million years ago. The result was new lines of animals which have populated the earth ever since. Predators appeared for the first time and this resulted in an arms race between predators and prey. There were many adaptations, and among them, improved distance sensing: vision, hearing and smell. Anthropoids and vertebrates in particular evolved high mobility and brains that improved sensory processing. A key change was image forming eyes. These allowed topographical maps of the retina. The other senses in vertebrates (except smell) re-evolved from a new cell line, on the pattern of the eye and its mapping in brain. In the resulting hierarchy of topographical maps for the senses, consciousness evolved.

I had assumed that the source of consciousness was lower in the brain than the cerebrum but was surprised by the location. The book documents it arising first in the optical tectum (superior colliculus in humans) and later extending to the thalamus and cerebrum, 220 years ago in mammals. This move not only added more layers to the existing hierarchies and put the top layer in close proximity to the sense of smell and its related memory in the cerebrum. This was a major advancement for consciousness for mammals and later for birds. Again I had to change my view as I had thought that memory and consciousness were always tightly bound.

The book also traces the evolution of affective consciousness (feelings and emotions), just as old as sensory consciousness. What was news to me was the intermingling of interoceptive bodily senses and affective limbic feelings giving three strains of consciousness.

The authors point out that the experience that the brain creates is embodied, personal, and does not include information about its creation – and therefore is wholly subjective and unique to each being. How this is done, the mechanism, is available to objective investigation. The subjective cannot see the objective and objective cannot see the subjective. There is a gap and it cannot be removed but neurobiological naturalism can ‘bridge’ it. This conclusion was not new to me as I have always been suspicious of whether the ‘hard question’ was really a question at all.

It’s a great book.

 

 

Meaning of Consciousness – part 4

For each science there seems to be a naïve folk version. There was a folk physics that allows people to predict that movement of physical objects, and so on with other sciences. This is still seen in expressions like ‘sun rise’ and the spontaneous beliefs on young children. Nothing is as it appears and we get used to the new knowledge. The sky is not as we thought – the stars and sun and moon are not as we thought. The earth is round. Gravity, light, heat are all different then we assumed. Solid material is mostly empty space. The earth is old and constantly changing. Life uses ordinary chemicals and there is no special essence of life. Life evolves. Our naïve folk versions of the world and our bodies have slowly been replaced by better explanations. But we still use a folk version of how the brain works. The unconscious processes were only recognized in the last hundred years. The nature of the brain is still more unknown than known. We guess this by the rate of surprising revelations that appear in the science journals, even the anatomy is not fixed. We are in for a revolution in how we understand our brains and like the Copernican Revolution, Darwinian Revolution and many smaller revelations, it will turn ideas upside down. This is hard – some people got physically dizzy when they learned that the earth rotates – back in the day.

How does the subjective nature of consciousness arise in a physical system? Is it impossible, or ‘an emergent property’, or a normal everyday process? I will pass over the impossible, magical answer. There is a definition of emergent property that has to do with hierarchical levels of scientific theories which I think misunderstands the nature of scientific reduction. What it really seems to mean in practice is that the speaker believes in a material world (or wants to hedge on it) but cannot find a path from a material brain to a subjective experience. So the subjective experience sort of ’emerges’ like a virgin birth from the material world by some new process or whatever that we have yet to find. But that process of emergence is not an ordinary one. Because I am a materialist (no hedging) I am not interest in the weird unknown emergent property. I am looking for a normal everyday process to explain subjective experience.

There really is a gulf here. In 2014 a Russian called Volkov invited 30 people – 9 important western thinkers (including Dennett and Chalmers) and teachers and students from the Moscow State University on a tall ship cruise along southern Greenland. They explored together on land in the mornings and had seminars in the afternoon. The idea was to come to some consensus. They had a great friendly time and in the end not one of them had changed their mind. Not much has changed since then.

To me, once we accept that what we have in consciousness is a model of the world and ourselves in it, that none of it is direct knowledge of the world or of ourselves but a model, then we seem home-free. That is what we have – only a model of the world and a model of ourselves in that world. Who then is the subject that is experiencing these models? If we do not watch out we will have a person inside a person inside a person to infinity. We cannot have a little person watching the screen because they would need perception, memory etc. and would in their turn produce a brain with a screen, to be watched by…. Who is the subject that has the subjective experience? It seem obvious that it must be the model of ourselves that is experiencing the model of the world and ourselves in it. And what we remember is ourselves experiencing the world; we remember a ‘subjective’ experience. It seems so simple. I find this notion very comfortable and satisfying, but then I really do find mysteries unsatisfying.

I have found someone who puts forward this notion or one very similar and more complete and backed up with evidence, Thomas Metzinger. He has written a book called The Ego Tunnel, and in it he lays out a lot of evidence for the idea. He is a philosopher but works with neuroscientists.

But we still have a semantic maze. From our folk psychology, Freudian ideas, and philosophy through the ages, we have accumulated a map of our mental life. Belief, pain, and will are examples of mental vocabulary. There is a rule of thumb in science, ‘cut nature at the joints’. Don’t name entities that are not natural entities. Many of the mental words can slip over to be useful scientific descriptors, but perhaps not all of them. And they may change somewhat in meaning. Take freewill for instance: cutting at the joints, scientist find a progression that goes – goal, plans, intention, execution but there isn’t really a place for freewill except as a marked in consciousness for the whole completed chain that indicates ‘I own responsibility for this action’. To science freewill no longer means freedom to act without the physical restraints of a material world but only decision we are responsible for because they were not forced.

But here is some stubbornness like the people who insist that pain is only what we feel in consciousness, nothing in the brain can be labeled pain only the ‘subjective’ experience. I just hate semantic arguments, and they will go on and on as knowledge progresses and words move from be mental descriptions to being physical descriptions.

Then there is the question of qualia or the colours, sounds, smells of our consciousness. Many cannot accept the idea that the brain could produce qualia. We know that perception gives us the wherewithal to assign shapes and many sorts of characteristics (like colour, movement, texture etc.) to objects. So all that is needed is how the world is assembled out of the results of perception in the global work space (which is not actually a physical space but a process). Through evolution of hundreds of millions of years, this process has been tuned to help us notice what needs to be noticed, recognize what needs to be recognized, understand what needs to be understood. If someone has a better way of doing this than colour, pitch and the other bound characteristics, I would really like to hear it. That is the way our brains model the world and it is an excellent way – built for survival.

There are more unknowns than knowns in how ours brains work. There are lots of surprises to come. But I am happy with the framework I have to fit to ideas into. A non-mysterious, physical, material, and beautiful framework.

Meaning of consciousness – part 3

What is the function of consciousness? Is the function thinking? There is type 1 thinking, unconscious thinking, and type 2 thinking, which we are conscious of. But it appears that what we are really conscious of is working memory, and not conscious of how an item is created and put in working memory. Type 2 thought is just unconscious processes using working memory as a tool for certain sorts of processing (some language, step-wise logic chains or calculations for example) and the contents of working memory are rendered into consciousness. If type 2 thinking is a function of consciousness then it implies that working memory is somehow dependent of consciousness.

We tend to associate moral responsibility with decisions made consciously, but for thirty of so years there has been growing evidence that we make decisions and execute actions unconsciously before registering them consciously. Libet’s experiment and its descendants just will not go away in spite of decades of trying. The notion that free will and ‘free won’t’ are functions of consciousness just will not work. What seems to be in consciousness is a metaphorical note saying, “I intended this action, I did it, and I morally own it.” There is a phrase, ‘fringe qualia’, which seem to be metaphorical notes about non-sensory information: states of mood and emotion, recognitions, ownership of actions and thoughts, important so take note, and so on. None of these arise within consciousness; they are add from and by unconscious processes. Consciousness can register responsibility for an action but not actually cause the action. There is a theory that consciousness is required to insure that there are not overlaps and gaps in motor plans. The idea is that the motor system needs a working model of the body and environment to proof its plans. This is probably true but not necessarily.

Is the function to give us a sense of self? The impression we have is that we are seeing the world through a hole in our heads around the bridge of the nose from about an inch and a half or so into the brain. But the ‘self’ is a complex mixture of what we control with our muscles, the sensory feelings from inside our bodies, sensory signals from the skin, our memories making a personal narrative, and very especially our consciousness. We naturally seem to identify with some sort of conscious ‘me/I’. Consciousness, as an awareness of ‘ourselves in the world’, has to create the watcher, listener, actor, that is in the world. Self seems essential to consciousness but not perhaps the central function.

Can memory be a function of consciousness? If we think about it, consciousness and memory do seem to go together, at least episodic memory. We remember things that we are conscious of and not things that we are unconscious of. We are aware we have been unconscious when there is a discontinuity in our memory train. It does not seem to require some sort of translation to bring a memory into consciousness – it appears to happen easily. It seems that imaginings are constructed of bits and pieces of memories and they also seem to fit into consciousness without effort. In order to remember experiences, we have to have experiences, and what is it that we experience – it is consciousness. the action. Consciousness can be experimentally tricked into being wrong, taking responsibility for actions the individual did not cause. But we are usually right. Knowing which actions we intentionally cause must be important to judging outcomes and learning from experience. Consciousness seems connected to various short-term memory systems: working memory, sensory memory, verbal memory. Episodic memory also is held together by a continuous self, all events and episodes happen to the same self. Consciousness may be what is prepared for episodic memory, the ‘leading edge’ of episodic memory, so to speak. Or it may be a monitor or newly formed memories, like the monitor head on a tape recorder. The creation of episodic memory would certainly be a function worth the biological cost of consciousness. Being part of the episodic memory system would fit with being an important anchor of the ‘self’. Even the metaphorical notes of the fringe qualia would fit it this episodic memory.

The question is – what exactly is the dependency of memory on consciousness. Episodic memory, imagination and consciousness seem to have the same basic nature or structure or coding. And this structure must be the vehicle of the subjective experience. I have looked for a clear statement of this idea in the literature and the closest seems to be the global workspace of Bernard Baars. He proposed a architecture that would give momentary active subjective experience of events in working memory, consciousness, recalled memory, inner speech and visual imagery.

Do other animals have consciousness? It certainly seems reasonable to assume that most vertebrates do. The source of the awake state comes from deep in the brain stem. Activity from there activates higher regions, the thalamus in particular. Awake, in animals, may not necessarily mean aware, but it would be wiser to assume awareness until proven otherwise, than to do as we have been doing, assume no awareness until proven otherwise. The cerebral cortex does not itself mount consciousness, it is done in partnership with the thalamus, probably be driven by the thalamus. It would seem that a rudimentary consciousness would be possible without a cerebral cortex. It has been found recently that split-brain subjects have one consciousness and not two. This implies that the source of consciousness is is not in the cerebral hemispheres, but must be in some lower region. But the vivid detail of the content must be from the cortex.

Still we do not have a explanation of the subjective nature of consciousness yet but that is for part 4.

 

Meaning of consciousness – Part 2

In part 1 a particular meaning of consciousness was picked out of the group of meanings. So what can be said about this neural idea of consciousness as simply awareness of self and surrounding world, here and now? Is it as it appears? Well, no.

To start with it is questionable whether it is a continuous stream, the ‘stream of consciousness’, as it seems to be. Instead It is likely to be discrete displays. A number of experiments (replicated a number of times) have shown that consciousness is not continuous. But there are also experiments that shown that it is not a straight forward series of frames as in a movie film. There is a fairly convincing in-between theory proposed by Herzag (PLOS Biol 2016). “We experience the world as a seamless stream of percepts. However, intriguing illusions and recent experiments suggest that the world is not continuously translated into conscious perception. Instead, perception seems to operate in a discrete manner, just like movies appear continuous although they consist of discrete images. To explain how the temporal resolution of human vision can be fast compared to sluggish conscious perception, we propose a novel conceptual framework in which features of objects, such as their color, are quasi-continuously and unconsciously analyzed with high temporal resolution. Like other features, temporal features, such as duration, are coded as quantitative labels. When unconscious processing is “completed,” all features are simultaneously rendered conscious at discrete moments in time, sometimes even hundreds of milliseconds after stimuli were presented.” They have a two stage model: a first stage of unconscious processing of features and the binding of these features to entities that ends after at least 400 milliseconds with a best fit solution and the triggering of the second stage of integration into a consciously perceived output. This precept is static but is labeled with features like colour, pitch and also duration, movement, location and the like. Although the precept is unchanging, it is experienced as having duration – as a slice of time although it does not exist for that duration.

This view of consciousness implies that we have no direct knowledge of how this conscious experience is created. We can report our conscious experiences but not how they were created or how accurate they may be. Introspection as a method of observing processes of thought is not a reasonable concept – it is not possible to interrogate the ‘mind’ subjectively, from the inside. “The human mind operates largely out of view, and yet people are unaware of their unawareness, confabulating reasons for their actions and preferences.” (Wilson Science 2008). Subjectively, creating consciousness is a transparent process. It can only be understood through objective study.

If perception is not done consciously and neither is motor control, exactly why do we need the conscious experience? It is almost like consciousness has no function – an extra that the brain does not need.

Chalmers put forward the distinction of the hard question and the easy question. This appears to be a new type of dualism, separating objective knowledge of consciousness from the subjective experience of it. There is an thought experiment called philosophical zombies. Why could there not be people who have no consciousness but who act the same as someone who does? This would mean that the function of consciousness in the brain does not include the experience of consciousness. The function of the easy part, the objective part, the neural part is separate from the function-less, hard, subjective, and mystical part. The core idea here is that a physical brain cannot produce a subjective experience, or if it does then it is by way of some special process that is not known to current science. It has been put forward that consciousness is a universal primitive like mass and everything has consciousness, or it ’emerges’ through some information theory mathematics in objects that are complex enough, or it is some product of quantum mechanics that has not been studied, or it is simply not physical but spiritual. So some people who try to explain consciousness are told that they have not explained it but ‘explained it away’ because the mystery is gone. And other people who try to explain consciousness are told that they have not explained it but made it a mystery because the physical world is over-stepped. This divide is unlikely to disappear in the near future. I have to say that I personally find it impossible to be a dualist. I want a physical explanation of consciousness, preferably in biological terms .

From my biological point of view, consciousness must have a function in the brain because it is very biologically expensive. It cannot just be entertainment. What function does experiencing ourselves in the world have? Does its reason of existence help explain it? That is for part 3.

Meanings of consciousness – part 1

How little do we agree on what consciousness is? Not much. The word itself (in English) has a number of separate meanings: a type of awareness, such as ‘class consciousness’; awareness in an everyday sense, ‘they were consciousness of the fact that the room would be cold’; a personal awareness of the current moment, ‘his consciousness was filled with bright lights and music’; all mental activity that a person is aware of, ‘conscious self’. There are also meanings that result from translations from words in various languages, cultures and religions that might be translated into words like soul, mind, spirit, or a universal connection. The meaning that I want to concentrate on is the personal awareness of the current moment. But there are still many ways to view this particular consciousness – in spite of view points almost all people agree that they experience this idea of consciousness and assume that their consciousness is like that of others. And there is a general idea that the brain in particular is involved. It is at about that point that the agreement stops.

Until recently Descartes’ notion of consciousness was generally accepted: the mind/consciousness/soul was spiritual and the brain was physical so that animals, with only a brain, were automations without consciousness, thought or feeling, while, humans had a soul/consciousness/mind as well as a brain. How this human dualism might actually be possible, was a puzzle that philosophers worked on for several hundred years and some are still engaged in the riddle. Dualism is now almost gone from science – consciousness is something that the physical brain does by physical processes in neuroscience. I say almost gone because it often creeps back under various guises into the scientific literature.

Given a physical consciousness, the next fork in the road was an question around mind. Freud had made popular the idea of a brain holding two minds, a conscious mind and an unconscious mind. (This is a simplification of his very elaborate theoretical structure.) These two minds were seen in a sort of opposition, with the conscious mind wearing the ‘white hat’ and the unconscious mind wearing the ‘black’ one. There was little known of neuroscience in Freud’s time and his theories are built with entities that we now think of as features of minds rather than brains. Mind ideas are no longer associated with unconscious processes – simply any activity that does not appear in consciousness is considered part of the unconscious brain and no ‘black hat’ is implied. There is still the question of how much consciousness can be thought of as a conscious mind. But in order to side step this question, it has become more and more common to use the word ‘consciousness’ rather than ‘conscious mind’ and ‘unconscious’ or ‘non-conscious’ rather than ‘unconscious mind’. But when people say something like ‘in my mind’ they tend to mean ‘in my conscious mind’ in the Freudian sense. There is a mental vocabulary as well as a neural vocabulary – but to date there is no one-to-one mapping between mental entities and neural ones. There are two possible structures here: conscious mind can imply everything that is, was ever, or could be experienced consciously, a working mind creating thoughts and willing actions; or, consciousness can imply the mechanism creating and the specific content of a moment of conscious experience or awareness. These are very different pictures. The notion of a conscious mind is what underpins introspection as a method of getting direct knowledge of our thought processes. But it has been shown in many ways that introspection is not reliable. So my interest in consciousness is an interest in the momentary experience of the world and our existence in it – the simple conscious experience. All else is unconscious processing (also interesting but not as consciousness).

Where is consciousness?

A particular type of epilepsy has been treated by cutting the corpus callosum, the tracks of nerves connecting the two hemispheres of the cerebrum. The result had very little side effects on the patients. However, with closer experimental studies, the nature of the split brain was examined. Only the left hemisphere spoke and so only stimuli presented to the left visual field resulted in spoken replies and responses of the right hand. The right hemisphere could understand written language presented to the right visual field and made responses with the left hand but never spoke. Based on this and similar evidence, it was assumed that there were two minds (that is two consciousnesses) in a split brain.

A recent paper has upset this hypothesis: Pinto, Neville, Otten, Corballis, Lamme, de Haan, Foschi, & Fabri; Split brain: divided perception but undivided consciousness; Brain Jan 2017. Here is the abstract:

In extensive studies with two split-brain patients we replicate the standard finding that stimuli cannot be compared across visual half-fields, indicating that each hemisphere processes information independently of the other. Yet, crucially, we show that the canonical textbook findings that a split-brain patient can only respond to stimuli in the left visual half-field with the left hand, and to stimuli in the right visual half-field with the right hand and verbally, are not universally true. Across a wide variety of tasks, split-brain patients with a complete and radiologically confirmed transection of the corpus callosum showed full awareness of presence, and well above chance-level recognition of location, orientation and identity of stimuli throughout the entire visual field, irrespective of response type (left hand, right hand, or verbally). Crucially, we used confidence ratings to assess conscious awareness. This revealed that also on high confidence trials, indicative of conscious perception, response type did not affect performance. These findings suggest that severing the cortical connections between hemispheres splits visual perception, but does not create two independent conscious perceivers within one brain.

When they showed an object in both visual fields and if the objects were the same or different, the split brain subject could not answer that question with either hand or by speech. They could not examine the objects together – so it was correct that the perception in the two hemispheres was separate and isolated. But if an object was placed in either or both visual fields, the subjects could say how many objects there were in total and there was no different in the answer coming from the left or right hand, or the voice. So although they could not examine the objects together, their consciousness covered the entire visual field – there was only one consciousness.

What can explain this if the results hold up? Perhaps the two hemispheres have learned unusual ways of communicating outside of the normal connections. Perhaps it is some dualistic magic. Or, to me more likely, consciousness is not a product of the cerebrum. It is created in some other part of the brain that can receive information from both hemispheres and can store its creation in immediate memory where it is available to the hemispheres. There is an obvious candidate, the thalamus. It is not cut in half by the cutting of the corpus callosum. It is connected to almost all areas of the brain and almost all information passes through it at some stage of its processing. It is the one part of the brain that must be functioning for consciousness to occur.

There has been for years an assumption that the cerebrum is the engine of thought and a number of things are puzzles because they cannot be understood looking at the cerebral cortex alone. It is time to thing about the possibility that the thalamus drives the cerebrum: it feeds information to the cortex, it creates the rhythms and synchronization in the cortex, and it controls the communication networks in the cortex. The thalamus may have the cortex as an on-line computer, to use that metaphor. But then the thalamus is in the center of the brain and the cortex is laid out on the surface. It is easier the examine the cortex and so the rest of the brain gets neglected. Like the man looking for his keys under the street lamp because the light is better there even though he lost them elsewhere.

 

Beta waves

Judith Copithorne image

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

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.

Click bait PR in science

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.

Fish integrate their senses

Judith Copithorne image

Judith Copithorne image

Consciousness seems to have at its foundation the melding of information from all the senses into a integrated model of the world (and ourselves in it). It would be impossible to meld a sound with a sight, for example, without having a common framework of space and of time. And without the different senses informing one another, they would lose much of their usefulness. Therefore when we see melding of sensory information into a model, we can guess that there is a good probability that some level of consciousness exists. Two recent papers on fish show this sort of hint.

The first paper (Thompson, Vanwalleghem, Heap, Scott; Functional Profiles of Visual-, Auditory-, and Water Flow-Responsive Neurons in the Zebrafish Tectum; Current Biology 2016) shows that the tectum integrates sense information in a similar way to the human superior colliculus. “In order to function efficiently, fish and humans need a unified sensory view of the external world contributed to by multiple senses”, says Ethan Scott.

Using calcium imaging in transparent zebrafish, the dynamics of visual processing were shown to replicate previous studies. When sound or waterflow stimuli were used, a small number of cells in the tectum responded, similarly to the visual response but not showing the same cells. The visual response was somewhat less when other signals were present at the same time. This was similar to processes in the mammalian superior colliculus – information from various senses is integrated there.

The second paper (Schumacher, de Perera, Thenert, von der Emde; Cross-modal object recognition and dynamic weighting of sensory inputs in a fish; Proceedings of the National Academy of Sciences 2016) showed that fish can switch between senses as do monkeys, dophins, rats and humans.

The elephantnose fish explores objects in its surroundings by using its eyes or its electrical sense – sometimes both together. The skin contains numerous sensor organs that perceive objects in the water by means of the changed electrical field. “This is a case of active electrolocation, in principle the same as the active echolocation of bats, which use ultrasound to perceive a three- dimensional image of their environment.” Electrolocation is more useful at close range and vision is better at longer distances. The fish can, in effect, turn off one of the senses if the information from the other sense is more reliable.

Using darkness to force electrolocation and electrically transparent objects to force vision, the researchers could study the switching of the senses. They found that the fish could remember, find and recognize shapes experienced with one sense when using the other sense. They form a model of the space which could be used by either or both senses.

It seems that fish form a model of the their environment that all their senses can contribute to in an integrated way.