thoughts on thoughts

Failure of conscious thought suppression

admin — Sun, 05 Feb 2012 12:54:20 +0000

Don’t think of a purple elephant – you know the game. It is practically impossible to manage this seemingly simple task. We will think about the suppressed thought, probably every minute or so. Why?

In fact, the more seriously we put effort into avoiding the thought, the more it comes to consciousness. In order to avoid the thought, we have to keep monitoring whether the suppression is working. We, in effect, keep asking ourselves whether a purple elephant is anywhere near our consciousness. Every once in a while, that unconscious monitoring pops the thought into consciousness.

This sort of mechanism can explain some social gaffs and freudian slips. We are just trying too hard to avoid certain subjects/words. If we were less nervous about those subjects it would be easier to avoid blurting out the unacceptable remark we are determined to avoid. I think some people call this ‘don’t mention the war’ effect after a famous Fawlty Towers episode.

I heard a story of someone trying to learn to ride a bicycle. They were finally staying upright and feeling pretty good. After a few moments there was a post along the path and they concentrated on avoiding it. The more they told themselves to avoid the post, the more they were aimed at it and in the end hit it (dead center).

What comes into the center of consciousness is what is important either because it was not predicted (a surprise) or because it is part of the on-going task we are trying to accomplish. Usually these are referred to as bottom-up and top-down steering of attention. We have to be careful not to turn a no-no thought into a top-down focus of attention.

What is the preconscious?

admin — Thu, 02 Feb 2012 05:50:43 +0000

I presume the word preconscious was first used by Freud and his meaning was thoughts that were not currently conscious but could be easily made conscious – all retrievable memory and perceptions that were not being attended to consciously would fit this description. It could be as wide as everything that is not repressed and not currently conscious. This does not seem a very useful designation.

A more modern use of preconscious is put forward by S Dehaene (director of INSERM-CEA group). It sounds very similar to Freud – ‘a transient state of activity in which information is potentially accessible, yet not accessed’ - but is quite different. He has three processes: subliminal, preconscious and conscious. Subliminal processing happens when there is not enough strength in the bottom-up signal for it to travel forward, preconscious processing happens when there is a feed forward but there is not enough top-down attention to trigger the reverberation of the thalamo-cortical network, conscious processing has sufficient bottom-up and top-down strength to ignite consciousness. The differences are that Dehaene is talking about processes not partitions of information, that he is not talking about escaping repression (or repression at all), and that he is not talking about information that is not current (such as the total of episodic memory as opposed to that part which might in a particular moment be recalled).

A recent paper, Pupillometry: a Window on the Preconscious, by Laeng and others, put another definition in the mix. They are dealing with very young babies. The preconscious is not mentioned in the abstract or press releases and is not mentioned in other papers of their that I have read (I am again not able to read to this particular paper in the origninal). I have not seen mention of consciousness, unconsciousness or preconsciousness in their other publications I have read so far and so I assume that they have a meaning like ‘before a baby is old enough to be fully conscious’. They are dealing with very young infants. Because changes in pupil size do not register consciously at any age it is unlikely that they are discussing the sort of thing that Freud or Dehaene are. This bit of the abstract is fairly clear, “given that pupillary responses can be easily measured in a noninvasive manner, occur from birth, and can occur in the absence of voluntary, conscious processes, they constitute a very promising tool for the study of preverbal (e.g., infants) or nonverbal participants (e.g., animals, neurological patients).” The meaning of preconscious seems to be ‘prior to attainment of consciousness through development, evolution or healing’.

I am sure there are people, not familiar with these concepts, that would have thought the word meant ‘on the way to being conscious but not there yet’, with the pre as a simple and quick time function. From Dehaene we have, “In a recent study of the attentional blink, we observed that up to about 180 ms after stimulus presentation, the occipito-temporal event-related potentials evoked by a invisible word were large and essentially indistinguishable from those evoked by a visible word. Yet on invisible trials, the participants’ visibility ratings did not deviate from the lowest value, used when no word was physically present. Thus, intense occipito-temporal activation can be accompanied by a complete lack of conscious report.” There needs to be a word for the part of early processing that is going to be conscious in another fraction of a second as opposed to the part that is going remain unconscious. Alas, this is not a way that the word, preconscious, is used as far as I can see.

So I will continue to avoid using the word – too confusing, too many possible meanings.

Are there two types of cognition?

admin — Mon, 30 Jan 2012 06:40:17 +0000

J. Evans’ 2008 paper reviews a number of proposed dual-processing descriptions of cognition. (see citation). He finds some stable divisions in the theories but a number of conflicting ones also. Calling the dual processing system 1 and system 2 appears to him to give a mistaken impression of how cognition works; he feels that processes (not locations, contents, parallel systems etc.) is the key difference and uses the terms type 1 and type 2.

A core type 2 is fairly easy to define – slow, sequential, limited capacity, associated with working memory and conscious experience. Around this core, various theories diverge. Type 1 seems almost impossible to define at present with much agreement, except that it is not type 2. It may not be (probably isn’t) a single type of process. I look for types 1a, 1b etc. in future.

Here is part of the concluding discussion in the paper:

Although dual-process theories have been around in cognitive and social psychology for 30 years and more, it is only within the past 10 years or so that the terms System 1 and System 2 have come into common use. … However, close inspection of the evidence suggests that generic dual-system theory is currently oversimplified and misleading. In particular, (a) it is not possible coherently to link together all the attributes associated with Systems 1 and 2 … and (b) there are at least two quite distinct forms of dual-process theory to be found in these various literatures that can not readily be mapped on to each other. We might be better off talking about type 1 and type 2 processes since all theories seem to contrast fast, automatic, or unconscious processes with those that are slow, effortful, and conscious. However, it would then be helpful to have some clear basis for this distinction. … My suggestion is that type 2 processes are those that require access to a single, capacity-limited central working memory resource, while type 1 processes do not require such access. This implies that the core features of type 2 processes are that they are slow, sequential, and capacity limited. The last feature implies also that their functioning will correlate with individual differences in cognitive capacity and be disrupted by concurrent working memory load. …

However, other proposed features of System 2 in the generic theory do not immediately follow from this definition of type 2 processes, for example, the proposal that such processes are uniquely human or associated with decontextualized thought or rule-based reasoning.

The problem with this distinction is that type 1 processes then simply refer to any processes in the mind that can operate automatically without occupying working memory space. As already indicated, there are a number of different kinds of such implicit processes. We may have innate cognitive modules with encapsulated processes for perception, attention, language processing, and so on. We appear to have an associative learning system that implicitly acquires knowledge of the world in a form similar to weights in neural networks; the knowledge cannot be called to mind as explicit knowledge, but it can directly affect our behavior. We have habitual and automated behavior patterns that once required conscious type 2 effort but seem to have become type 1 with practice and experience. We also have powerful pragmatic processes that rapidly identify and retrieve explicit knowledge for conscious processing. Type 2 processing requires supporting type 1 processes to supply a continuous stream of relevant content into working memory. If there are indeed multiple kinds of type 1 processes, then it is to be expected that psychologists will have developed different kinds of dual-process theories, which seems to be the case. …

In short, my conclusion is that although dual-process theories enjoy good empirical support in a number of fields of psychology, the superficially attractive notion that they are all related to the same underlying two systems of cognition is probably mistaken, at least in the way that Systems 1 and 2 are being defined in the current literatures. For example, it is almost certainly wrong to think of System 1 as one system, all of which is old and shared with other animals. Equally, it is probably a mistake to think of System 2 as the conscious mind, all of whose processes are slow and sequential. If there is a second system, distinctively human, involving working memory and neurologically distinct structures, it does not follow that all of its workings are conscious and controlled. It is perfectly possible that one system operates entirely with type 1 processes and that the other includes a mixture of type 1 and type 2 processes, the latter being linked to the use of working memory, which this system uses - among other resources. Such a proposal could resolve the conflict between evidence for dual systems on the one hand with the proposals of different dual-process theorists on the other.

Dual-processes of cognition seems the wrong description of what is likely to be a very complex mixture of types and combinations of types. Again reality refuses to be neatly divided into just two parts.

J. Evans (2008). Dual-Processing Accounts of Reasoning, Judgement, and Social Cognition Annu. Rev. Psychol. (59), 255-278

The new way to view cognition

admin — Fri, 27 Jan 2012 05:36:15 +0000

This year’s Edge question is “What is your favorite deep, elegant, or beautiful explanation?”. If you want to read all the answers go (here). Simone Schnall has answered with embodied cognition and its solving of the questions of meaning and grounding.

Philosophers and psychologists grappled with a fundamental question for quite some time: How does the brain derive meaning? If thoughts consist of the manipulation of abstract symbols, just like computers are processing 0s and 1s, then how are such abstract symbols translated into meaningful cognitive representations? This so-called “symbol grounding problem” has now been largely overcome because many findings from cognitive science suggest that the brain does not really translate incoming information into abstract symbols in the first place. Instead, sensory and perceptual inputs from every-day experience are taken in their modality-specific form, and they provide the building blocks of thoughts. …following the cognitive revolution in the 1950ies psychology treated the computer as the most appropriate model to study the mind. Now we know that a brain does not work like a computer. Its job is not to store or process information; instead, its job is to drive and control the actions of the brain’s large appendage, the body. A new revolution is taking shape, considered by some to bring an end to cognitivism, and giving way to a transformed kind of cognitive science, namely an embodied cognitive science. … The basic claim is that the mind thinks in embodied metaphors. … But it does not stop here; there is also a reverse pathway: Because thinking is for doing, many bodily processes feed back into the mind to drive action.

She uses the metaphor of verticality (up/down) and morality (good/bad) to illustrate how the metaphors work.

The growing recognition that embodied metaphors provide one common language of the mind has lead to fundamentally different ways of studying how people think. For example, under the assumption that the mind functions like a computer psychologists hoped to figure out how people think by observing how they play chess, or memorize lists of random words. From an embodied perspective it is evident that such scientific attempts were hopelessly doomed to fail. Instead, it is increasingly clear that cognitive operations of any creature, including humans, have to solve certain adaptive challenges of the physical environment. In the process, embodied metaphors are the building blocks of perception, cognition, and action. It doesn’t get much more simple and elegant than that.

Of course, there are many people who have not accepted that the computer model of the brain is finished. They point out that computers can simulate brains (or more or less anything). But there is a difference between being able to simulate the weather in order to predict it and treating a computer as the model of how the weather engines work. The same applies to brains. Computers are very useful tools for studying various simulations of the brain, but the brain is not a computer.

About the claustrum

admin — Tue, 24 Jan 2012 09:11:38 +0000

It is that time of year – time for the Edge question. When I see this on the menu it gives me a little tingle. This year’s question is “What is your favorite deep, elegant, or beautiful explanation?”. If you want to read all the answers go (here).

Here is part of V. Ramachandran piece on Crick’s many explanations. This bit is about his claustrum idea.

In biology, knowledge of structure often leads to knowledge of function—one need look no further than the whole of medical history. … I believe there are similar correlations between brain structure and mind function, between neurons and consciousness. I am stating the obvious here only because there are some philosophers, called “new mysterians,” who believe the opposite. … After his triumph with heredity, Crick turned to what he called the “second great riddle” in biology—consciousness. There were many skeptics.

Crick did not, in my opinion, succeed in solving consciousness (whatever that might mean). Nonetheless, I believe he was headed in the right direction. He had been richly rewarded earlier in his career for grasping the analogy between biological complementarities, the notion that the structural logic of the molecule dictates the functional logic of heredity. Given his phenomenal success using the strategy of structure-function analogy, it is hardly surprising that he imported the same style of thinking to study consciousness. He and his colleague Christoff Koch did so by focusing on a relatively obscure structure called the claustrum.

The claustrum is a thin sheet of cells underlying the insular cortex of the brain, one on each hemisphere. It is histologically more homogeneous than most brain structures, and intriguingly, unlike most brain structures (which send and receive signals to and from a small subset of other structures), the claustrum is reciprocally connected with almost every cortical region. The structural and functional streamlining might ensure that, when waves of information come through the claustrum, its neurons will be exquisitely sensitive to the timing of the inputs.

What does this have to do with consciousness? Instead of focusing on pedantic philosophical issues, Crick and Koch began with their naïve intuitions. “Consciousness” has many attributes—continuity in time, a sense of agency or free will, recursiveness or “self-awareness,” etc. But one attribute that stands out is subjective unity: you experience all your diverse sense impressions, thoughts, willed actions and memories as being a unity—not jittery or fragmented. This attribute of consciousness, with the accompanying sense of the immediate “present” or “here and now,” is so obvious that we don’t usually think about it; we regard it as axiomatic.

So a central feature of consciousness is its unity—and here is a brain structure that sends and receives signals to and from practically all other brain structures, including the right parietal (involved in polysensory convergence and embodiment) and anterior cingulate (involved in the experience of “free will”). Thus the claustrum seems to unify everything anatomically, and consciousness does so mentally. Crick and Koch recognized that this may not be a coincidence: the claustrum may be central to consciousness; indeed it may embody the idea of the ” Cartesian theater” that’s taboo among philosophers—or is at least the conductor of the orchestra. This is this kind of childlike reasoning that often leads to great discoveries. Obviously, such analogies don’t replace rigorous science, but they’re a good place to start. Crick and Koch may be right or wrong, but their idea is elegant. If they’re right, they’ve paved the way to solving one of the great mysteries of biology. Even if they’re wrong, students entering the field would do well to emulate their style. Crick has been right too often to ignore.

I visited him at his home in La Jolla in July of 2004. He saw me to the door as I was leaving and as we parted, gave me a sly, conspiratorial wink: “I think it’s the claustrum, Rama; it’s where the secret is.” A week later he passed away.

The general notion today is that consciousness is not localized in a particular place and is spread across the cortex, but given Crick’s record and methodology it might be a good idea to look at the claustrum.

Two sides of synchrony

admin — Sat, 21 Jan 2012 06:44:33 +0000

Humans often engage in synchrony (as do mating birds and other animals). We sing, chant, dance, march together. We have special work songs to coordinate movement. Synchrony is enjoyable. It also takes some of our autonomy and gives it to the others that we are in sync with. This can be good and bad depending on the group and its aims. And it seems to have a very powerful effect on consciousness - almost like a high.

We can see the usefulness of work songs. The coordination make everyone’s efforts more effective. There is a feeling that you are not pulling alone and that whatever your effort is, it is not being wasted. I would guess that anyone not putting in effort when it was rhythmic would be easy to spot and so the synchrony might also be an enforcer of cooperation.

Wiltermuth and Heath in their 2009 paper showed that synchronous movement or singing does indeed enhance a group identity and produced behaviour that was more group oriented even at the individuals expense.

Taken together, these studies suggest that acting in synchrony with others can lead people to cooperate with group members. While the studies do not eliminate the possibility that muscular bonding and collective effervescence may, under the right conditions, strengthen the effects of synchrony on cooperation, our results show that synchronous action need not entail muscular bonding or instill collective effervescence to create a willingness to cooperate. Our results suggest that cultural practices involving synchrony (e.g., music, dance, and marching) may enable groups to mitigate the free-rider problem and more successfully coordinate in taking potentially costly social action. Synchrony rituals may have therefore endowed some cultural groups with an advantage in societal evolution, leading some groups to survive where others have failed .

Cooperating in positive group activities is one side but the other negative side is the rejection of people outside the group. Synchrony is used in war dances and modern military displays. While sports teams are competing on the field, their fans are competing in the stands in shows of synchrony.

Wiltermuth in his 2012 paper showed the aggressive results of synchrony. His studies indicate that synchronous activities may be used to influence leader-follower relations. Marching and chanting are used rallies to influence people across the world and the centuries. Think Hitler.

An experiment demonstrates that cultural practices involving physical synchrony can emotionally bind people together, making those people more likely to comply with others’ requests to engage in aggressive behavior. Participants who acted in synchrony with a confederate were more likely than were participants in the asynchronous and control conditions to comply with the confederate’s request to administer a noise blast to another group of participants. Increased feelings of emotional connection with the confederate mediated the relationship between synchrony and heightened compliance with the request to engage in aggressive behavior.

Do we have any protection against being lead astray by synchrony? Maybe we have. Many people have a natural loner rather than joiner character which makes them suspicious of group displays. The first part of getting in sync is to mimic others. It seems we naturally mimic those we are with and do not realize we do it. But only if we share goals with the others. That is a nice little safety catch!

Ondobaka and others showed this in their 2011 paper.

Observing the movements of another person influences the observer’s intention to execute similar movements. However, little is known about how action intentions formed prior to movement planning influence this effect. In the experiment reported here, we manipulated the congruency of movement intentions and action intentions in a pair of jointly acting individuals (i.e., a participant paired with a confederate coactor) and investigated how congruency influenced performance. Overall, participants initiated actions faster when they had the same action intention as the coactor (i.e., when participants and the coactor were pursuing the same conceptual goal). Participants’ responses were also faster when their and the coactor’s movement intentions were directed to the same spatial location, but only when participants had the same action intention as the coactor. These findings suggest that observers use the same representation to implement their own action intentions that they use to infer other people’s action intentions and also that a dynamic, multitiered intentional mechanism is involved in the processing of other people’s actions.

This reminds me a bit of oxytocin – it creates empathy to the in-group and increasing xenophobia for the out-group. It is great in the family and small community but a problem in the bigger world.

So when you become consciously aware of that nice, warm part-of-group feeling, take a moment to look at the group’s aims, before joining in the song and dance.

Wiltermuth, S., & Heath, C. (2009). Synchrony and Cooperation Psychological Science, 20 (1), 1-5 DOI: 10.1111/j.1467-9280.2008.02253.x

Ondobaka, S., de Lange, F., Newman-Norlund, R., Wiemers, M., & Bekkering, H. (2011). Interplay Between Action and Movement Intentions During Social Interaction Psychological Science, 23 (1), 30-35 DOI: 10.1177/0956797611424163

Wiltermuth, S. (2012). Synchronous activity boosts compliance with requests to aggress Journal of Experimental Social Psychology, 48 (1), 453-456 DOI: 10.1016/j.jesp.2011.10.007

Skull shape changes are not independent

admin — Wed, 18 Jan 2012 05:59:27 +0000

ScienceDaily had an item (here) on research (Martínez-Abadías and others, Pervasive genetic integration directs the evolution of human skull shape. Evolution, 2011) showing that human history may have intertwined evolutionary pressures rather than sequential ones.

They worked with a unique set of skulls that could be matched with good genealogical data to test various theories of skull shape determinants. In particular they looked at changes that were important in human evolution: the shift of the foramen magnum where the spinal cord enters the skull associated with upright walking, the retraction of the face associated with chewing soft food (cooked using of fire?) and vocalizing, and the rounding expansion of the top of the skull associated from increased neocortex mass leading to tool making, language, general smarts. These have been thought to have evolved independently.

(The researchers) found that, rather than being separate evolutionary events, changes in one part of the brain would facilitate and even drive changes in the other parts. “We found that genetic variation in the skull is highly integrated, so if selection were to favour a shape change in a particular part of the skull, there would be a response involving changes throughout the skull,” said Dr Chris Klingenberg.

Previously, environmental pressure were postulated separately for each of these three changes. This research points to a more fluid evolution where specific pressures might not be needed for some changes or where several less powerful pressures might work together.

Here is their abstract:

It has long been unclear whether the different derived cranial traits of modern humans evolved independently in response to separate selection pressures or whether they resulted from the inherent morphological integration throughout the skull. In a novel approach to this issue, we combine evolutionary quantitative genetics and geometric morphometrics to analyze genetic and phenotypic integration in human skull shape. We measured human skulls in the ossuary of Hallstatt (Austria), which offer a unique opportunity because they are associated with genealogical data. Our results indicate pronounced covariation of traits throughout the skull. Separate simulations of selection for localized shape changes corresponding to some of the principal derived characters of modern human skulls produced outcomes that were similar to each other and involved a joint response in all of these traits. The data for both genetic and phenotypic shape variation were not consistent with the hypothesis that the face, cranial base, and cranial vault are completely independent modules but relatively strongly integrated structures. These results indicate pervasive integration in the human skull and suggest a reinterpretation of the selective scenario for human evolution where the origin of any one of the derived characters may have facilitated the evolution of the others.

What does this have to do with consciousness? Maybe it has nothing to do with it, but it does remove the need for specific causes for every difference between human and other great ape brain proportions.

the other way around

admin — Sun, 15 Jan 2012 10:11:51 +0000

Some ideas can just be backwards. Take the famous ‘I think therefore I am’. There are not that many people who actually question whether or not they exist. The idea that I might doubt my existence but not my thought is somewhat odd. The implication is that introspection has more reality than reality itself. The opposite idea is that reality is really real and introspection is an inaccurate, sometimes illusionary, ‘copy’ of it. Now, Descartes was a great thinker for his time but a lot has happened since 1637. Science started only a few years before. Science has been studying the physical world for much of the intervening time making reality much more understandable and, as a result, dualism has fallen out of fashion. Well, that Descartes type of dualism anyway. But we go on dividing things in two.

There was a time when it was reasonable to assume that what we now call consciousness was thought and all of thought. It is what we experience and all other mental activity is inferred or deduced. There seemed one mind and it was the mind we had experience of. But deduction and inference has been going on for some time and now it appears that most thought is carried on without coming to conscious awareness. It would be reasonable to assume that there is only one mind and we are aware of part of what that mind does. We are not longer forced to either the naïve version of only conscious thought or the dualist version of two minds (conscious and unconscious) with two types of thought. We do not actually know how the brain functions – it is possible that there are a number of different thought processes, 6 or 7. Why 2? Personally, I would bet money on there being so much integration that it will be seen as one process in time.

Then we have gone on and divided animals into humans and other animals; an extremely old divide. But over time, the more we know about biology, the more that humans fit right into animals of the higher ape variety. The things that defined us as very different have fallen away one by one. Other animals use tools, they deceive, they make plans, time travel, have theories of mind, similar emotions and on and on. All that is left it seems is language and even that is not fully secure with parrots, dogs, elephants, dolphins and so on having traces of something close to the line. In order to preserve the human position as somehow very different from animals we have made a taboo of anthropomorphism. We feel we must resist any assumption that animals are like us until the we are forced to give up by evidence. In biochemistry, biophysics, physiology, anatomy we are animals with very few distinguishing features (no more than any other animal). Why should we assume that our psychology and behavior is extremely different, a difference of kind rather than degree.

I am getting very suspicious of anything that comes in exactly two distinct varieties. If it turns out to be a spectrum with two names for the extremes – OK. But two distinct types – I suspect that someone likes to have a duality here and I need to be convinced.

A look at the dogma

admin — Thu, 12 Jan 2012 10:55:08 +0000

The authors of a new paper (citation below) have doubts about some well known ‘facts’ in neuroscience. I have to admit I assumed that the numbers were backed by evidence. I may have used these numbers in posts and so I feel bound to share the doubts with readers. Here is the abstract:

Owing to methodological shortcomings and a certain conservatism that consolidates wrong assumptions in the literature, some dogmas have become established and reproduced in papers and textbooks, derived from quantitative features of the brain. The first dogma states that the cerebral cortex is the pinnacle of brain evolution – based on the observations that its volume is greater in more ‘intelligent’ species, and that cortical surface area grows more than any other brain region, to reach the largest proportion in higher primates and humans. The second dogma claims that the human brain contains 100 billion neurons, plus 10-fold more glial cells. These round numbers have become widely adopted, although data provided by different authors have led to a broad range of 75– 125 billion neurons in the whole brain. The third dogma derives from the second, and states that our brain is structurally special, an outlier as compared with other primates. Being so large and convoluted, it is a special construct of nature, unrelated to evolutionary scaling. Finally, the fourth dogma appeared as a tentative explanation for the considerable growth of the brain throughout development and evolution – being modular in structure, the brain (and particularly the cerebral cortex) grows by tangential addition of modules that are uniform in neuronal composition. In this review, we sought to examine and challenge these four dogmas, and propose other interpretations or simply their replacement with alternative views.

They give the conventional wisdom as: intelligence is related brain size, brain size is related to cerebral cortical size. But they point out that the cerebellum keeps its ratio with the cortex, the cerebellum has more neurons that the cortex by a factor of 4 and, further, has a lot to do with intelligence. Although the neuron density is much higher in the cerebellum, there are many fewer glial cells.

The idea that humans are outliers on graphs of body size against brain size ignores the difference in various types of animals. We are not dramatically off the line for higher primates.

Cortical columns are thought to contain 147,000 neurons in each cylinder of about 1mm squared at the surface (except for a few areas) across all mammals. But this has not stood up to evidence. Surface area increases more slowly than neuron numbers and there is not a firm relationship between density and thickness.

Here are some figures and their error ranges given in the paper:

Whole Brain

1509(+- 300) grams / 171(+- 14) billion cells / 86(+- are neurons and 85(+-10) glia

Cerebral cortex grey and white matter

1233(+- 234) grams / 77(+-8) billion cells / 16(+- 2) are neurons and 61(+-7) glia

81% of brain mass 19% of brain neurons

Cerebellum

154(+- 19) grams / 85(+- 7) billion cells / 69(+- 7) are neurons and 16 (+- 2) glia

10% of brain mass 80% of brain neurons

Basal ganglia and diencephalon and brainstem

118(+- 45) grams / 8.5(+- 1.5) billion cells / 0.7(+- 0.1) are neurons and 7.7(+-1.5) glia

8% of brain mass 1% of brain neurons

Surprised?

Lent, R., Azevedo, F., Andrade-Moraes, C., & Pinto, A. (2012). How many neurons do you have? Some dogmas of quantitative neuroscience under revision European Journal of Neuroscience, 35 (1), 1-9 DOI: 10.1111/j.1460-9568.2011.07923.x

the Freud hangup

admin — Mon, 09 Jan 2012 05:29:20 +0000

It continues to amaze me that there are still scientists who have very kind words to say about Freud’s theories. I tend to think that the leftovers of his ideas have a very negative effect on neuroscience.

Here the sort of thing I mean. Jonah Lehrer who is a great (I mean great) blogger, starts a recent posting (here) with this paragraph:

Sigmund Freud gets a bad rap from modern science. (The immunologist Peter Medawar summarized the feeling of many with his remark that psychoanalysis is the “most stupendous intellectual confidence trick of the twentieth century.”) Sure, Freud’s theories mangled a lot of details — we no longer worry about penis envy or the Oedipus complex — but he was shockingly prescient on the big themes. In recent years, it’s become clear that, as Freud always insisted, the unconscious is the dominant force in our mental life. (What Freud called the id is now a network of brain areas associated with emotion, such as the amygdala and nucleus accumbens.) He was mostly right about the logic of dreams, which often regurgitate those parts of experience we store in long-term memory. And he was basically correct to imagine the mind as a set of conflicted drives, with reason competing against the urges of the passions. We expend a lot of neurotic energy holding ourselves back.

The paper that Lehrer is reviewing does not mention Freud or Freudian theories. It discusses infant attachments to mothers, but in a modern not Freudian way. When I read this paper it did not remind me of Freud.

So Freud insisted that the unconscious is the dominant force. That seems to me to be a small positive compared to the large negative in the kind of dominance he gave it. He painted that dominant force as the dark side in opposition to consciousness. Freud’s picture is all conflict and sabotage; it is unrealistic and to me has always been unconvincing. This Freudian fear of the unconscious is actually holding back the recognition of its importance.

A reasonable picture is of parts of the brain cooperating most of the time to protect an individual’s well-being. Instead of artificial divisions, science is more and more finding that parts are working together or achieving balance rather than fighting.