28/12/2011 by admin.

Back on Nov 29, S. Golonka posted an interesting piece (here ) exploring the idea of ‘mind’. She puts in the context of a fairly universal idea across cultures, that of a visible and invisible division.

In a larger sense, the fact that there seems to be a universal belief that people consist of visible and invisible aspects explains much of the appeal of cognitive psychology over behaviourism. Cognitive psychology allows us to invoke invisible, internal states as causes of behaviour, which fits nicely with the broad, cultural assumption that the mind causes us to act in certain ways.

In this scheme, mind is the invisible part. But different cultures approach the invisible part differently, sometimes dualistically and sometimes not. In the scientifically viewpoint, mind is thought, memory, problem-solving, reasoning, maybe emotion, rarely seen dualistically but as processes of the body.

In Korean, mind is translated to ‘maum’, the seat of emotions, motivation and goodness, and the rest is body. Japanese have mind as ‘kokoro’, the seat of emotion and a source of culturally valued attention to, and empathy with, other people and ‘hara’ is the source of will and motivation. Russian has ‘dusa’ associated with feelings, morality, and spirituality and is responsible for the ability to connect with other people. It is often translated as soul rather than mind.

Wierzbicka is quoted:

If we uncritically formulate some hypothetical universals in one particular natural language, for example, English, we run the risk of distorting them by imposing on them the perspective embedded in that particular language; and the same applies to our description of cultural differences.

I think the key is not visible and invisible, but visible and hypothetical. In order to understand ourselves and others we imagine a process. This has to be a relative good hypothesis to be useful predictively but it can miss the mark in reality. We talk about emotions, feelings, will, morality and so on as if they were single ideas and real things, where as they could be extremely different from our imagining. For example, our emotions could be a mixed bag of different sorts of processes, in different places and with different sorts of effects. It is our hypothesis that links them firmly together. The same may be true of morality, of motivation etc. We always have to be careful of the words both that we use and that other cultures use.

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25/12/2011 by admin.

We have various ways of moving. Here are four obvious ways and there may be more. First, a spinal cord reflex happens without the involvement of the brain at all. We have no forewarning of it or way to stop it, but we can block it ahead of time by a sort of steeling against it – example removing finger from burning heat. Second, there are inborn and learned patterns that we do without thinking but can do by decision – example blinking. Third, there are well learned complex patterns that we are almost always aware of and can initiate but do not think about on a continuing basis – example walking. Fourth, there are actions which we think about and decide to do – decide to take the red one rather than the blue when offered a choice. As any action can result in a good, neutral or bad outcome, we need to know what kind of an action it was to know how to deal with the outcome.

What we need is the way to mark actions as one of: not ours, automatic, the result of our unconsidered decisions and the result of our considered decisions. We need to know what it was that caused the action. What is the involvement of consciousness in this marking? Our actions are committed to episodic memory with a sense of how the action came about. Do I ‘own’ this action? If someone bumps my elbow and therefore I move in a way that spills my drink, I do not own the spill; I did not do it. But if my muscles are moved by my body – I own the movement. But I may not have intended it – I sneezed and spilled the drink. I’m sorry but I didn’t do it on purpose. Or I forgot I had the drink in my hand – I didn’t mean to do that, I was not paying attention and I should have been; sorry. Or I may have intended it – putting out a fire or making a physical criticism of the quality of the wine.

For those actions were it is possible, what we register consciously is: an intention to act, followed by an initiation of an action, followed by the sensation of doing the action. It is reasonable (if we are naïve) to assume that the action is the result of the initiation which is the result of the intention. Not so. The way actions happen is different from the way they are marked in our conscious experience. We know this from three types of experiment.

The famous experiments of Libet (see citation) showed that the motor action was being prepared before the subject was aware consciously of his intent to act. Therefore the conscious intent could not be the cause of the action. This does not mean that there was no intent to act but just that the conscious awareness of intent was not the cause of the action, some sort of unconscious intent was the starting point.

Wegner’s experiments (see citation) showed that people will take ownership of actions that are not their or refuse ownership of actions that are theirs. If the timing is right between the subject thinking about some action and perceiving the action, if they could physically do the action and if there is no better agent for the action around, then they will feel they did it even if they have been manipulated by experimental tricks with priority, consistency and exclusivity. They can also reject having done something that they did by the same sort of manipulation in reverse. This means that what we experience is not knowledge of our motor actions but a cognitive judgments of what they must have been (in other words, good guessing).

Desmurget and his group (see citation) have done experiments on the relationship between action and the consciousness of action. They show that correlation is being confused with causation. The posterior parietal cortex does sensory predictions but not motor commands and if it is stimulated mildly the subject senses the intention to do something. A stronger stimulation gives the subject the illusion that the intended action is happening. But stimulation of the PPC does not result in any action at all only the conscious experience of the desire, initiation and execution but no actual movement. On the other hand stimulation of the premotor cortex results in a movement but no conscious awareness of intent or action. Without experimental direct stimulation, in ordinary life, these areas with others, produce a predictive conscious model of what is happening but the conscious experience is not causal – definitely not causal. The conscious experience does mark the type of action in memory though and this is a useful function.

I wish that the freewill-v-determinism argument would go to some dark corner and die. We should forget both notions as not useful and concentrate on how and why our brains actually work. Consciousness can be extreme important to understanding and learning from our actions without actually being in the causal path. It marks the type of action in the episodic memory and it is the predictive model used to monitor action.

LIBET, B., GLEASON, C., WRIGHT, E., & PEARL, D. (1983). TIME OF CONSCIOUS INTENTION TO ACT IN RELATION TO ONSET OF CEREBRAL ACTIVITY (READINESS-POTENTIAL) Brain, 106 (3), 623-642 DOI: 10.1093/brain/106.3.623

Wegner, D., & Wheatley, T. (1999). Apparent mental causation: Sources of the experience of will. American Psychologist, 54 (7), 480-492 DOI: 10.1037//0003-066X.54.7.480

Desmurget, M., Reilly, K., Richard, N., Szathmari, A., Mottolese, C., & Sirigu, A. (2009). Movement Intention After Parietal Cortex Stimulation in Humans Science, 324 (5928), 811-813 DOI: 10.1126/science.1169896

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22/12/2011 by admin.

What determines how much short-term memory can hold? ScienceDaily has an item on this (here). The paper is by J.Kaminski etal., Beta band oscillations engagement in human alertness process, in International Journal of Psychophysiology.

A human being can consciously process from five to nine pieces of information simultaneously. During processing these pieces of information remain in the short-term memory. In 1995 researchers from Brandeis University in Waltham suggested that the capacity of short-term memory could depend on two bands of brain’s electric activity: theta and gamma waves. However, only now, through carefully designed experiments conducted at the Nencki Experimental Biology Institute of the Polish Academy of Sciences (Nencki Institute) in Warsaw, it was possible to unambiguously prove that such a relationship really exists…The hypothesis formulated by Lisman and Idiart in 1995 assumes that we are able to memorise as many ‘bites’ of information, as there are gamma cycles for one theta cycle. Research to date provided only indirect support for this hypothesis…Only based on discovered correlations the ratio of the length of theta wave to gamma wave was determined and the likely capacity of verbal short-term memory was determined…Following the EEG recording, the volunteers, were subjected to classic short-term memory capacity test…(They) observed that the longer the theta cycles, the more information ‘bites’ the subject was able to remember; the longer the gamma cycle, the less the subject remembered… correlation turned out to be very high and it confirmed the hypothesis of Lisman and Idiart.

So we can manipulate as many of ‘bits’ of information in short-term memory as we can fit beta waves into a single theta wave. Each ‘bit’ would be carried by a beta wave.

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19/12/2011 by admin.

In this series, we are looking at how it is that consciousness is worth its biological cost and in this post we come to what some would consider the essence of consciousness – global awareness. The content of consciousness is widely available in the brain. It seems that areas/processes of the brain have varying amounts of connectedness. The brain is more or less at the limit of the amount of white matter it can house to connect all its gray matter. If thought is restricted to neurons firing and connected by axons and dendrites, consciousness appear near impossible because there seems no way for every signal to pass to spatially and functionally distant areas.

I am dyslexic and long before there was modern theories about what this problem really was, I had the feeling of a blocked path and the need to find a different path around the block. In the days of my youth there was no diagnosis or therapy for dyslexia so I (later with my husband) had to develop ideas of what was wrong and therapies to deal with the problem. One attempt was to learn to read Russian script out loud and write it from dictation, without learning the meaning of any words. The idea was to practice a form of phonetics while bypassed semantics. I studied etymology to try and separate spelling from sound. I did cryptic crosswords. Slowly connections were made and slowly they stopped needing consciousness to be effective. I still have dyslexia in that I ‘hear’ whole words and syllables rather than phonemes and this still causes some problems in reading, writing and learning a new language, but I have learned how to cope. I am convinced that not every part of the brain can connect directly with every other. If the foundation for connection is not there (as one is missing in dyslexia), it will not just appear because you need it.

When we learn new things (say playing the piano), we start by working at a conscious level and practicing until we no longer need to be aware of the find detail of what we are doing – they become automatic. We are learning new things all the time – new people, new places, new things, new tasks and so on. If consciousness was not there, we would only be able to learn those sorts of things that evolution had very specifically prepared us for.

But how is this global communication done? I have not encountered a clear authoritative description and so I assume that it is still a mystery to be solved. But there are things that seem likely. The availability of the content of consciousness has to do with rhythms (as do many biological functions).

If you are not familiar with biological rhythms, you may want to consider as an example: the heart muscle – it beats. If the heart cells are separated, the individual cells beat as beating is part of the physiology of being a heart muscle cell. But the beating is also contagious and a cell will contract if a neighbour cell contracts. On top of this there is a period of time after a contraction when the cell cannot contract again until it has recovered. In the intact heart the fastest beating cell captures the others. When it contracts, others do by a contagious wave, then all the cells enter an inactive state and the first one to beat next is that fastest one. They all beat to the fastest beat – that of the pace-maker cell. It is not just muscle cells throughout the body who beat, neurons can also maintain rhythms and their beating can be captured by a local pace-maker neurons. Hearts are simpler but the brain situation is much more complicated.

Without going into great detail, EEG activity has conventionally been described in terms of a set of wide frequency bands, usually defined from slowest to quickest as: delta (1.5–3.5 Hz), theta (3.5–7.5 Hz), alpha (7.5–12.5 Hz), beta (12.5–25 Hz), and gamma (25–50 Hz). Different functional systems produce these rhythms. The spectrum comes from complex homeostatic systems involving brainstem, thalamus, and cortex and utilizing all neurotransmitters. Pacemakers in the thalamus interacting with the cortex and other areas causes synchronous oscillation in the alpha range as sensory signals are feed into the cortex. The nucleus reticularis can hyperpolarize the thalamic neurons and slow this rhythm to the theta range, decreasing sensory input to the cortex. Theta activity is generated in the limbic system and associated with memory activity. Delta activity is believed to originate in neurons in deep cortical layers and in the thalamus. It is normally inhibited by input from the lower brain controlling the amount of alertness/sleep. Activity in the beta band reflects cortico-cortical and thalamo-cortical transactions related to specific information processing. Gamma activity reflects cortico-thalamo-cortical and cortical-cortical reverberatory circuits, which play an important role in perception. These frequencies are indications of synchrony in the firing of neurons and also of phase-locking of a faster rhythm to a particular place on a slower rhythm.

As well as pace-maker neurons firing, synchrony is also affected by local field potentials. Neurons fire when their membranes pass a threshold as the voltage difference between inside and outside decreases. So the outside environment is part of the threshold. If the local field potential becomes nearer to a neuron’s inside field, the neuron is more likely to fire. LFPs are the product of many influences including other neurons near by, the glial cells packed around the neurons and the glial calcium ion communication (also rhythmic). There are magnetic fields that may affect the activity of neurons. It seems to me that there are long years of work ahead in clarifying the causes. interactions and effects of brain rhythms. But it does seem that the contents of consciousness are ‘broadcast’ across the brain during a very particular wave of sustained synchronous activity from the frontal cortex back across the length of the cortex to the primary sensory areas involving the parietal and other parts of the cortex and the thalamus.

To illustration the sort of activity involved, here is a very interesting video. (here). The time is not speeded up or slowed down, the colors indicate frequency ranges, the sounds are not simplified but the frequencies only made auditory and moved into a good range for human hearing. The resolution of time and location is only as good as the original fMRI scan. One can almost see the communication of information involved in consciousness in this video.

There is more to come. Previous posts in this series:

Possible functions of consciousness 1 - leading edge of memory

Possible functions of consciousness 2 – gate to meaning

Possible functions of consciousness 3 – working memory

Possible functions of consciousness 4 – place to imagine

Possible functions of consciousness 5 – create ‘now’

Possible functions of consciousness 6 – presence ‘here’

Possible functions of consciousness 7 – attention on the significant

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17/12/2011 by admin.

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16/12/2011 by admin.

In a previous post (here) I remarked on a pair of papers that I had not be able to read in full but only had the abstracts. A kind reader, G. Marchetti (http://www.mind-consciousness-language.com), has let me see these papers (citations below). I am relieved that I did not make any ‘oopses’ in understanding the abstracts. There were ideas in the papers that I didn’t touch on in that post and will now.

First the Bilalic paper:

Recognizing human faces is one of the most essential visual skills—and also one of the most practiced ones. Since the very beginning of our lives, we have been exposed to faces as a major source of social information. The neural substrates of face recognition have been extensively studied. One of the most important brain structures for face perception is the fusiform face area (FFA), located in the right lateral part of the midfusiform gyrus. Some researchers even proposed that the FFA is a specific module exclusively devoted to face recognition. This face-specificity hypothesis contrasts with the expertise hypothesis, which maintains the FFA is a general expertise module specialized for perceptual processes associated with visual individuation.

This idea of individuation is important here. We do not view faces as types as much as we think of them as particular people, often with their own name. This is an area for the kind of discrimination that carries a proper noun for identification. Presumably this is the area that would deal with any sort of object where a large number of similar ones must be treated as each being one of a kind. Off hand, chess does not seem ideal as a source of individuation. But it does seem a good source of similar patterns with very different significances and easy to experiment with (starting with an expert rating available).

They showed that faces activate the FFA more than chess boards – this was no surprise as the subjects see more faces than boards. Also they showed that the activation of chess boards was expertise-modulated, and therefore being used by chess experts.

It is difficult to explain our results solely with attentional effects. IPS, an attention-related area, was engaged in all tasks, but there were no differences between experts and novices. … indicates that the FFA activation was probably independent of task difficulty and the attentional processes necessary in this particular context.

The FFA is not distinguishing just patterns, but meaningful ones. It seems that pattern is not enough and the ‘intent’ component of real games is need. I think this is very important. Chess boards are very unlike faces and other types of expertise that have been studied in the FFA (for example bird watchers). But chess patterns are meaningful; they can be view in a holistic way by experts and they have some of the spirit of intentions/goals/rules/meaning.

An additional piece of evidence that the FFA effects are not related to the mere complexity is the pattern of results on normal and random positions. Both position types are comparable in that they involve a similar number of chess objects forming interrelations on the same full chess board. Only normal positions, however, contain relational patterns between chess pieces that are meaningful to experts. FFA appears to be responsive to this subtle distinction, as shown by the different activation levels between normal and random positions among experts only.

The non-visual and the non-holistic processing of chess boards and of faces takes place elsewhere:

Our results indicate that FFA is not directly related to core expertise processes but that it may support some of them indirectly by processing the stimuli holistically. The real utilization of stored chess knowledge by experts seems to be mediated by the collateral sulcus. It should be noted, though, that even in face perception, we have a dedicated network of brain structures, which are responsible for different processes. … Simple stimuli (e.g., isolated chess pieces), which do not consist of complex relational patterns formed by clearly distinct individual elements, may not engage holistic processing properties of the FFA. In contrast, naturalistic multipart stimuli (e.g., faces, full-board chess positions) seem to invite holistic processing in experts, mediated by increased FFA activity.

The Bilalic paper used real people with real FFAs but a expertise that is not typical. The Tong paper on the other hand uses more typical classes of objects but computer models of the learning process instead of people. It is also an older paper.

They start with a interesting definition of what an expert is rather than the ready made ranking of Bilalic’s chess players.

We use Gauthier’s operational definition of the term: experts are as fast to verify that a picture of an object is a particular individual (subordinate level) as they are to verify their category membership (basic level). For example, a bird expert would be as fast and as accurate at verifying that a picture of a bird is an “Indigo Bunting” as at identifying it as a “bird.” On the other hand, a novice will show the fastest reaction time at the basic level, and is slower at both subordinate and superordinate level. The basic level was first identified by Rosch as the level at which objects tend to share the same shape and function, and tend to correspond to the first word we use to describe an object (a picture of a chair is labeled “chair” rather than “furniture” or “office chair”). When training a subject in a novel category, the downward shift in reaction times in this task is taken as evidence of expertise.

The experiments were done with electronic networks which ‘learn’ to make distinctions by trial and error. The networks change the weights of the signals between ‘neurons’ in the hidden layers between input and output when they are learning. The hidden layers can then be characterized by the researchers. The researchers used two types of input/output which made the networks learn in the style of non-experts (basic) and of experts.

By analyzing the hidden layers of the two types of networks, we found that expert networks spread out the representations of similar objects in order to distinguish them. Conversely, basic networks represent invariances among category members, and hence compress them into a small region of representational space. The transformation performed by expert networks (i.e., magnifying differences) generalizes to new categories, leading to faster learning. The simulations predict that FFA neurons will have highly variable responses across members of an expert category.

What does this tell us to expect in the FFA?

What the results do suggest is that if the FFA is performing fine-level discrimination, then that task requires it to develop representations of the stimuli that separate them in representational space—the neural responses are highly differentiated. That is, similar objects have the differences between them magnified by the expert networks. On the other hand, networks that simply categorize objects map those objects into small, localized regions in representation space (this is in the space of neural firing patterns, and should not be confused with spatially localized representations).

What does this say about consciousness? This blog is, after all, about consciousness. There is a saying – if you don’t know how it’s done then it’s easy. Recognizing individuals by their faces, voices, whole bodies etc. just effortlessly happens for us – it just happens and therefore it seems easy. If it were a conscious process it would not be invisible, we would know how it is done (or at least the steps involved) and it would be seem hard. To us recognizing people and even predicting their actions ‘just happens’ and anything that ‘just happens’ involves an enormous amount of processing that is transparent to consciousness. Pattern recognition is not a conscious thing – by its nature it cannot be.

Tong, M., Joyce, C., & Cottrell, G. (2008). Why is the fusiform face area recruited for novel categories of expertise? A neurocomputational investigation Brain Research, 1202, 14-24 DOI: 10.1016/j.brainres.2007.06.079

Bilalić M, Langner R, Ulrich R, & Grodd W (2011). Many faces of expertise: fusiform face area in chess experts and novices. The Journal of neuroscience : the official journal of the Society for Neuroscience, 31 (28), 10206-14 PMID: 21752997

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13/12/2011 by admin.

I have had in mind, since a friend suggested it, to provide a glossary for readers who have an interest in the brain but somewhat spotty knowledge of it and the words used to describe it. Now I think that the world does not need my version of a glossary, but instead needs links to existing material that was written by experts for non-experts. So here are some links you can bookmark and use:

The Society for Neuroscience has produced an 80 page booklet which covers the nervous system at a basic but useful level and includes both a glossary and a full index. It can be download here -

http://www.sfn.org/skins/main/pdf/brainfacts/2008/brain_facts.pdf

DANA press has a pdf publication on brain imaging methods which comes with an at-a-glance section at the end. The pdf can be downloaded from this website -

http://www.dana.org/news/publications/publication.aspx?id=34292

Christof Koch has written a webpage, Definitions of Terms relating to the study of consciousness and the brain. It is found here -

http://www.klab.caltech.edu/~koch/glossary.html#p-c

Wikipedia has a good entry on the 52 Brodman areas, that their other names are, and where they are on a map of the brain. At the bottom of this entry is a click-able map of the areas that links to specific entries for the individual areas.

http://en.wikipedia.org/wiki/Brodmann_area

Wikipedia also has two other entries that can help with names and locations -

http://en.wikipedia.org/wiki/List_of_regions_in_the_human_brain

http://en.wikipedia.org/wiki/Human_brain

The Brain from Top to Bottom is a site that contains a great deal of information. You can navigate through various topic areas at various levels of expertness and with the viewpoint of various areas of scholarship.

http://thebrain.mcgill.ca/flash/index_i.html

And if you have a favorite site that you think is as good or better than these or covers an area that is missed here – send the link in a comment. Thank you.

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10/12/2011 by admin.

Attention and consciousness are often thought to be inseparable or even two words for the same thing, but under unusual circumstances they can be separated. It is not easy to separate them and so what consciousness does to assist attention would be an important function of consciousness to the extent that attention was important to survival. Well that’s a no brainer – all you have to do is not attend to what is happening when cross a busy road to understand the risk to survival of not attending to the important things. Surely this function alone would pay the biological cost of consciousness.

Consciousness, in effect, is a canvas on which the spotlight of attention can fall so that all areas of the brain can know what is currently important and so that part of the canvas can be rendered in more detail. What steers the spotlight? We have mechanisms to keep the brain focused on a task or goal, thought of as top-down control, and mechanisms to shift focus to unusual or alarming sensory input, thought of as bottom-up control. This keeps what is significant in awareness and available to the whole brain. All the resources of the brain can be brought to the important problem of the moment. Because what is currently significant is in consciousness, it is also in memory. We start memories with the most important aspect of each consecutive moment.

Victor Lamme and his group have studied attention and consciousness with, to my mind, a very reasonable attitude – forget introspection etc. and let the neurological evidence rule. Looking at the neural correlates of consciousness – the fast forward wave and the feedback wave with its synchrony across large areas of the cortex – and controlling the visual stimulus, they find the following.

Because depth of processing (attention) and the fast forward sweep (FFS)/ recurrent processing (RP) distinction are orthogonal, a visual stimulus can reach any of four stages of processing:

• Stage 1: Superficial processing during the FFS; This would happen when a stimulus is not attended and is masked. Unattended and masked words, for example, do not activate word-form selective areas, only visual areas, so do not even penetrate deeply into the ventral stream hierarchy.

• Stage 2: Deep processing during the FFS; for example, a stimulus that is attended, yet masked (and hence invisible). This stimulus does travel through the whole hierarchy of sensory to motor and prefrontal areas, and may influence behavior, as in unconscious priming.

• Stage 3: Superficial processing of a recurrent/ re-entrant nature (RP); for example, a visual stimulus that is given sufficient time to evoke RP (i.e., is not masked within ∼50 ms) yet is not attended or is neglected, as in neglect, inattentional blindness , change blindness, or the attentional blink.

• Stage 4: Deep (or a better word may be “wide-spread”) RP. This is the case when RP spans the whole hierarchy from low level sensory to high level executive areas. This occurs when a stimulus is given sufficient time to engage in RP and is attended. Others have equated this to the situation that a stimulus has entered global workspace .

Or this description:

Initially, all objects are processed by low level areas in a feedforward fashion, so that basic features are extracted at about 100ms (Stage 1). Some objects are processed more deeply at about 200ms (Stage 2), depending on top down and bottom up attentional selection. Meanwhile, recurrent processing in early visual areas emerges also at about 200ms (Stage 3) for all or most of the objects. Later still, at about 300 msec, recurrent processing grows more widespread (Stage 4) for those objects that are selected by attention (potentially slightly different ones than those that were favored initially, as attentional selection is influenced by previous processing). After stimulus removal, Stage 3 processing turns into iconic memory, while Stage 4 processing turns into working memory.

It is difficult to envisage how what is significant could be decided and broadcast without the use of some structure like consciousness awareness in which it can be tagged. And it is hard to see how the brain could work without global priorities.

Besides the significance, there is an aspect of attention that is connected with language. E.B. Bolles (here) has been writing about this for a few years – and in his theory, the words in language steer attention so that the speaker and listener can mutually focus on the same topic. So if I start by saying ‘the car’ then my listener will focus attention on some object that fits that description and/or the concept of ‘car’ in the listener’s mind. This steering of attention may be a further reason (beside the need to use working memory) why language is almost always conscious. I will be returning to language again later.

There is more to come. Previous posts in this series:

Possible functions of consciousness 1 - leading edge of memory

Possible functions of consciousness 2 – gate to meaning

Possible functions of consciousness 3 – working memory

Possible functions of consciousness 4 – place to imagine

Possible functions of consciousness 5 – create ‘now’

Possible functions of consciousness 6 – presence ‘here’

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08/12/2011 by admin.

Do people have a different shade of consciousness when improvising jazz? I picture a jazz musician standing with his eyes closed, in a sort of trance, completely lost from the world, flowing zen-like with the spontaneous music, expressing his own sense of beauty in the thread he weaves into the fabric of the group. Limb and Braun (see citation) have published a paper on the changes in brain activity during improvisation.

Their description of this state:

It has also been suggested that deactivation of the lateral prefrontal regions represents the primary physiologic change responsible for altered states of consciousness such as hypnosis, meditation or even daydreaming. This is interesting in that jazz improvisation, as well as many other types of creative activity, have been proposed to take place in an analogously altered state of mind. Moreover, a comparable dissociated pattern of activity in prefrontal regions has been reported to occur during REM sleep , a provocative finding when one considers that dreaming is exemplified by a sense of defocused attention, an abundance of unplanned, irrational associations and apparent loss of volitional control, features that may be associated with creative activity during wakefulness as well.

But the jazz improvisation is not without structure – it follows rules, some general to the genre and some deeply personal. The music is new and fresh but not outside some limits or random or meaningless.

What happens in the brain? Limb and Braun did fMRI scans on 6 experienced right-handed jazz pianists while they rested and while they played a scale, improvised on that scale, played a practiced piece with a jazz group backing through headphones, and improvised to the same backing. Recordings were also taken from the keyboard midi output to check on the details of the playing. There was high correspondence between the subjects and between the simple and complex improvising.

There was a change in the prefrontal cortex activity. The activity of the front middle was increased and the back and sides were decreased. The middle of the prefrontal cortex is in general associated with an autobiographical narrative. It has a role in the neural instantiation of self, organizing internally motivated, self-generated, and stimulus-independent behaviors. The portion of the front of this area (frontal polar cortex) is very selectively activated during improvisation. It is poorly understood but appears to serve a broad-based integrative function, combining multiple cognitive operations in the pursuit of higher behavioral goals, in particular adopting and utilizing rule sets that guide ongoing behavior and maintaining an overriding set of intentions while executing a series of diverse behavioral subroutines. All of these functions are necessarily required during the task of improvisation.

In other activities it has been found that attention and conscious self-monitoring can inhibit performance as well as spontaneity. The areas that were deactivated:

are thought to provide a cognitive framework within which goal-directed behaviors are consciously monitored, evaluated and corrected. The LOFC (lateral orbitofrontal cortex) may be involved in assessing whether such behaviors conform to social demands, exerting inhibitory control over inappropriate or maladaptive performance. The DLPFC (dorsolateral prefrontal cortex), on the other hand, is thought to be responsible for planning, stepwise implementation and on-line adjustment of behavioral sequences that require retention of preceding steps in working memory.

There was increased activity in the sensorimotor areas. This is probably because of the extra effort require to plan and implement new (not practiced or remembered) motor patterns and heighten sensory perception. At the same time there was decreased activity in some limbic areas. Music in general affects the limbic area both increasing and decreasing activity in various parts. This is not surprising given the link between music and emotion. The authors do not mention the idea of a suppression of memory and habit being a possible explanation although I think that it would contribute.

Here is their abstract:

To investigate the neural substrates that underlie spontaneous musical performance, we examined improvisation in professional jazz pianists using functional MRI. By employing two paradigms that differed widely in musical complexity, we found that improvisation (compared to production of over-learned musical sequences) was consistently characterized by a dissociated pattern of activity in the prefrontal cortex: extensive deactivation of dorsolateral prefrontal and lateral orbital regions with focal activation of the medial prefrontal (frontal polar) cortex. Such a pattern may reflect a combination of psychological processes required for spontaneous improvisation, in which internally motivated, stimulus-independent behaviors unfold in the absence of central processes that typically mediate self-monitoring and conscious volitional control of ongoing performance. Changes in prefrontal activity during improvisation were accompanied by widespread activation of neocortical sensorimotor areas (that mediate the organization and execution of musical performance) as well as deactivation of limbic structures (that regulate motivation and emotional tone). This distributed neural pattern may provide a cognitive context that enables the emergence of spontaneous creative activity.

Limb, C., & Braun, A. (2008). Neural Substrates of Spontaneous Musical Performance: An fMRI Study of Jazz Improvisation PLoS ONE, 3 (2) DOI: 10.1371/journal.pone.0001679

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04/12/2011 by admin.

I spent some time many, many years ago in wondering what effective pre-scientific predicting was like. The predictions I was wondering about were not omens from entrails and the like, but good prediction of natural things made without the understanding that we now use. How did ancients forecast the weather for example?

At some point I ran across some person using the biblical phrase “ye can discern the face of the sky; but can ye not discern the signs of the times?” That phrase ‘discern the face of the sky’ is either as old as the original biblical texts or a medieval idiom used in early English translations. In either case it was from before knowledge of clouds, winds, air pressure etc. So the thought came – if you are trying to predict a system that has very complex patterns of elements are not understood – if you personify the system and try to get to feel for the patterns in terms of facial expressions, tones of voice, emotions, intentions, personalities – then you can use all the mental abilities that we have evolved for understanding and predicting people. Then you can learn how to predict weather, keep getting better at it for a life time, share/compare with others, and teach the skill to your children. You get to know the west wind’s personality. You get to see when the sky intends to freeze.

Deric Bownds’ blog (here) has a abstract that reminded me of ‘the face of the sky’. The paper is Bilalic, Langner, Ulrich, Grodd (2011) Many Faces of Expertise: Fusiform Face Area in Chess Experts and Novices, The Journal of Neuroscience:

The fusiform face area (FFA) is involved in face perception to such an extent that some claim it is a brain module for faces exclusively. The other possibility is that FFA is modulated by experience in individuation in any visual domain, not only faces. Here we test this latter FFA expertise hypothesis using the game of chess as a domain of investigation. We exploited the characteristic of chess, which features multiple objects forming meaningful spatial relations. In three experiments, we show that FFA activity is related to stimulus properties and not to chess skill directly. In all chess and non-chess tasks, experts’ FFA was more activated than that of novices’ only when they dealt with naturalistic full-board chess positions. When common spatial relationships formed by chess objects in chess positions were randomly disturbed, FFA was again differentially active only in experts, regardless of the actual task. Our experiments show that FFA contributes to the holistic processing of domain-specific multipart stimuli in chess experts. This suggests that FFA may not only mediate human expertise in face recognition but, supporting the expertise hypothesis, may mediate the automatic holistic processing of any highly familiar multipart visual input.

Unfortunately, I am not able to access the paper. And there was another paper that I also found interesting in the abstract but could not access - Tong, Joyce, Cottrell (2008) Why is the fusiform face area recruited for novel categories of expertise? A neurocomputational investigation:

What is the role of the Fusiform Face Area (FFA)? Is it specific to face processing, or is it a visual expertise area? The expertise hypothesis is appealing due to a number of studies showing that the FFA is activated by pictures of objects within the subject’s domain of expertise (e.g., cars for car experts, birds for birders, etc.), and that activation of the FFA increases as new expertise is acquired in the lab. However, it is incumbent upon the proponents of the expertise hypothesis to explain how it is that an area that is initially specialized for faces becomes recruited for new classes of stimuli. We dub this the “visual expertise mystery.” One suggested answer to this mystery is that the FFA is used simply because it is a fine discrimination area, but this account has historically lacked a mechanism describing exactly how the FFA would be recruited for novel domains of expertise. In this study, we show that a neurocomputational model trained to perform subordinate-level discrimination within a visually homogeneous class develops transformations that magnify differences between similar objects, in marked contrast to networks trained to simply categorize the objects. This magnification generalizes to novel classes, leading to faster learning of new discriminations. We suggest this is why the FFA is recruited for new expertise. The model predicts that individual FFA neurons will have highly variable responses to stimuli within expertise domains.

Their question – ‘exactly how the FFA would be recruited for novel domains of expertise’ – may be that we use a person (or group of persons as in chess) as a sort of default alternative and this allows all of the power of our understanding of others to be used for novel domains. Not a bad trick.

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