Friday, September 12, 2008

The (eight) basic adaptive problems faced by all animals (esp humans)

Today I discovered a new blog called The Amazing world of Psychiatry, and this book review of Introducing Evolutionary Psychology by Evans and Zarate caught my eye. As I own a copy, so I had a quick look and indeed found the book very pleasurable to read (Its in comic book format) and recommend it wholeheartedly.

In it Dylan Evans and Oscar Zarate claim that all animals, and especially humans face a few adaptive problems and have developed modular adaptions in the brain to handle those problems that were encountered in the EEA. now , the massive modularity hypothesis is a topic for another day; today I'll restrict to how they had organized their typical adaptive problems into seven groups and how I propose to modify it by introducing an eighth group to make it more in line with my eight stage evolutionary and developmental theory.

To quote:

So what are the adaptive problems faced by our hominid ancestors? Various considerations drawn from Biology, Primateology, Archeology and Anthropology suggest what the most important adaptive problems would have been:

  1. Avoiding Predators
  2. Eating the Right Food
  3. Forming Alliances and Friendship
  4. Providing help to Children and other Relatives
  5. Reading other people's minds
  6. communicating with other people
  7. selecting mates

They then go on to describe each problem and the corresponding modules that evolved to serve these needs.

I'll now elaborate a bit on the thesis and would like to split the 4th level into two: one for parental investment and parent-offspring related issues and second with kin-selection issues. I'll draw heavily on their work. Its also my thesis that most of these (at least the first five issues ) are faced by most higher animals , like all mammals.The evolutionary problems and the specific modules they give rise to are described below:

  1. Avoiding Predators:The first need for a gene to be successfully passed in further generations, and thus be selected for, is that it enables the possessing organism to survive (against predators) and avoids them being eaten away. Thus the prime importance of this adaptive problem to be solved cannot be stressed enough. This problem can be solved by a) detecting predators b) detecting false alarms and c) taking action (running away (flight), freezing or fighting it).
  2. Eating the right food: The second problem, once you have avoided being eaten and wiped out of the gene pool, is to exploit your environment to the fullest such that you can enhance and maintain the robot (organism) that is carrying you (the gene). In other words, find food to sustain oneself and meet metabolic needs. Here not only rich sources of food need to be detected, but bad and poisonous sources avoided. Emotion of Disgust as well as the sweet tooth are result of adaptations to this problem. To generalize it, you need to discover, exploit and protect resources that could nourish you and avoid those that can harm you. I would club territoriality behavior and food ranges also as another module related to this same adaptive problem. You have to exploit your environmental niche to the fullest and be the fittest.
  3. Forming alliances and friendships : The third problem, for those animals that are not solitary, and are social in nature, is to form alliances and friendships within the group to which they belong. Group avoidance of predators (which may be big for an individual) and group sharing of food (big game hunting/ unpredictable foraging/ agriculture etc) is more beneficial than solitary hunting/ predator avoidance/food gathering. But with group formation comes the problems of group living - co-operation evolution and maintenance and the free-rider problem. Basically, how to detect cheaters and free-riders who take benefits from the group but do not pay back. If unchecked, the genes conferring such free-riding behavior will proliferate in the gene pool and destabilize co-operation and thus effective groups. It has been proposed by Robert Axelrod, that co-operation can evolve only if a) organisms encounter each other repeatedly (live in a group) b) they can recognize those they have met before and distinguish them from strangers and c) organisms can remember how those they have met before have treated them on previous occasions. Thus we need modules for recognizing con-specifics and for remembering their past actions, for solving this adaptive problem; many animals including elephants, who live in large groups, have solved this problem to an extent. This model is called reciprocal altruism and the strategy used is called tit-for-tat strategy in a repeated prisoners dilemma game of whether to co-operate or to defect. This also lays the foundation for a social exchange module whereby one calculates the costs and benefits keeping in mind the context under which the favor was given/ received.
  4. Helping Children / Parental investment: Most of the animals reproduce and that too sexually. In case of sexual reproduction, the child contains only half the genes of each parent and thus from gene's point of view an offspring's welfare is only half as important as one's (parents ) own welfare. So it might be conceived that the selfish gene would juts work towards prolonging the life of the organism that contains it, but at some point the benefits of reproducing and passing the genes to future generations may become more cost-effective in the long run. But, reproduction is not a child's play! The mother (in most animals) usually invests a lot of her energy and resources while gestating or lactating. The father too, in many species, including humans has to expend considerable resources to the well-being of his dependent children. Parent-offspring conflict arises as for parents all children are equivalent (in terms of gene value), but for siblings a sibling is only half as worth as self. A parent has to decide how many offspring to have to maximally pass on the genes. One approach could be to have a big litter; but this reduces the individual care or investment the parent can make in a child; thus leaving many to die or in hands of fate. The other strategy could be to have a few children , but to invest heavily in them so that most of them do live to reproduction themselves and are able to pass the genes forward. These two strategies are known as the r-strategy and the K-strategy of mating and parental care and apartment investment respectively. However along with strategies for parent investment , the most prominent problem to be solved by this adaptive problem of helping children, is to be sure that they are your children! Thus, mate guarding , jealousy , sticking to monogamy (and love which makes you monogamous in the critical parental investment period) , a mothering/fathering caregiver module may be some modules that are brought forth as a measure of solving this adaptive problem of how best to reproduce and let ones genes pass on through direct descendants.
  5. Helping Kin or Kin-selection: While ensuring survival of individuals and direct descendants is beneficial to the gene; it also benefits from inclusive fitness i.e. if some other related / unrelated organism that contains the gene survives at the cost of the original organism carrying the gene. Hamilton first formulated this using his famous equation that an organism will act altruistically to help another member (that is benefit other at cost to oneself) if r> c/ b; where r is how related you are to the individual in question (r is 1 for self, 0.5 for siblings/ children who share half the genes, 0.25 for first cousins etc ) , c is cost to yourself and b is benefit to the individual in question. Thus as it is difficult (though not impossible ) to determine from overt behavior/ phenotype, the genotype of the organisms (the famous green beard problem) , the only clue one has to whether one shares anthers genes is the degree of relatedness. Thus, other things being equal, one would favor one's kin above others leading to nepotism. But more than that the chief feature of this level of selection is captured by the phrase that one could die to save two siblings, four first cousins, eight second cousins etc. Thus, though one would get nothing in return, one would still co-operate and help. This mechanism is definitely different from reciprocal altruism that we discussed in the context of social exchange. However, with this level of selection comes the additional problem of how to identify kin and people carrying similar genes. I don't think people have asked this question much, (except for relatedness coefficients) , so there is scope for much work here. I propose that a minimum one would need a family-stability and family-institution-concept module to ensure that indeed whom one encounters the most are one's blood relatives. Similarly, a trust module would be present to trust the fidelity of your parents, uncles, aunts , grandparents, children etc, so that what you believe as blood relatives are indeed blood relatives. I also believe that biases may be build into us, such that we treat people more similar to us favorably and this could be the working of this module. We all know this bias that we have that if someone is like us or mirror our actions/ accent etc, we tend to favor him over others. This could be a result of this mechanism whereby we try to ascertain or make an approximation of the genotype of the individual from his phenotype and try to see how similar it is to our genotype. In short, we favor those who look and behave like us; or are related to us by blood ties.
  6. Reading other minds: Till now we have looked at how genes work at the level of individual (avoiding predators, eating food) , level of a few close fiends/ alliances , at the level of nuclear family (parents -offspring) and at the level of extended family (kin-selection) to ensure that they are passed on. Although in each case it is the genes that are selected for, they act at a level of an organism or a unit of organisms and show their effects most in interactions amongst that unit. Now its time to move a notch higher and move towards group-selection mechanisms whereby genes show their effects at the group level where the group is big enough (say the society/ population in which one lives). For humans this group size of a day-to-day interactions is supposed to be 150. (the size of our ancestor bands). Despite not being related to someone by way of kinship, alliance or friendship, when one lives in a group one has to work with other people with which one may or may not have good relations. To ensure survival of ones kin/ friends over ones enemies one needs to indulge in a bit of Machiavellian intelligence. This involves keeping track of who is sleeping with whom (and using that information to ones advantage) or indulging in some social politics. Information becomes paramount and thus rumor, reputation management and gossip is important!! It is presumed that this social intelligence was a driver for human large brain evolution. It is important to keep track of who is allied with whom and to use this knowledge well in forming alliances with an enemy of a common enemy. However, at the same time it is important to tolerate enemies, when one is not in a strong position and in general not to reveal ones true intentions, desires, beliefs etc to others. Information(social) is advantage. At the same time realization dawns that others may be concealing things from oneself and thus a need to know their true intentions, thoughts, beliefs. Thus a need for a Theory of Mind module that would keep track of what others are thinking or about what has been left unstated (by way of behavior). Thus, to be able to compete with one's con specifics , who may not be related or friendly and may have hidden, selfish intentions, it becomes important to read their minds properly and to mislead them, even using deception or lies to ensure that one is helped even by those who might not have the best interests in their heart.
  7. Communicating with others: This level of selection would ensure a generalized-reputation-based -reciprocity wherein the individual helps others based on how this individual has helped others in the past. If one can ensure that reputation of an individual correctly reflects his co-operative nature, then this sort of co-operation based on reputation can emerge. However, one needs to solve the problem first of what the reputation of an individual is. This is usually using the gossip mill mechanism, wherein having a good communicative ability is essential. In short, problem to be solved: correct reputation or credibility: modules involved: gossip, language etc.- level of selection: society or whole group that can properly ascertain correct reputations and benefit from reputation-based altruism will thrive/ flourish. Typical module: the language acquisition device.
  8. Mate-selection: This is sexual section and I believe is self-explanatory. This however can lead to arbitrary features developing that are not adaptive in the traditional sense; so this is a whole new level of evolution. This also leads to runaway evolution and emergence of beauty like the peacocks tail which are non-utilitarian . This via assortative mating may also lead to speciation. The idea is to improve the genotype and not just survive/ reproduce/ thrive; so one mates with another individual having 'best' compatible genes. Problem to be solved: best compatible genotype that will result in best offspring . Best is relative as the only best thing about them may be that the offspring can find a mate and thus ensure that the lineage continues. A recursive definition of best.


As you can make out , I am quite excited by this line of work. My thesis has always been that evolutionary/ developmental constraints have lead to the eight stages that we see in most phenomenon. I can readily map most of the eight stage phenomenons to these evolutionary problems. By way of an example consider the eight basic story plots. These enduring myths or basic plots are embedded in our memory becuase the hero solves a particular evolutionary problem and that acts as a parable for all others. Consider this:
  1. Overcoming the Monster plot ( avoiding predator)
  2. Rags to Riches plot (finding food/ resources): how one successfully gets resources like money.
  3. Quest plot ( forming friends and alliances) : the most important element of such plots is the journey in which a hero is accompanied by some friends and allies.
  4. Voyage and return plot( might be related to parental investment conflicts) :one goes on a journey in a different land and returns. cant fit this in, sorry about that!
  5. Comedy plot: (kin selection): the typical plot involves family disjointed, twins to create confusions, disguised identities etc: overall recognizing similar people and kin.
  6. Tragedy plot (might be related to Machiavellian manipulations and theory of mind confusions) : tragedy normally follows because one did not understood the unsaid correctly and made false premises.
  7. Rebirth (communicating with others) ; haven't read Christopher Booker's book till here so cant comment!!
I'm convinced! What about you?

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Wednesday, September 10, 2008

Movement and perception disorders : a case for dissolution?

I have touched upon the work of Hughlings-Jackson earlier, albeit very obliquely, and readers familiar with with his work will know the immense contributions he has made to the understanding of epilepsy and other neurological disorders. I was recently reading the Croonian Lectures on the Evolution and dissolution of human nervous system and I encourage my readers to read the 3 lectures in their entirety. Let me briefly try to summarize his approach to brain first:

Hughligs Jackson believed that the brain had evolved. Also that the human brain is heterogeneous with three distinct evolutionary distinct components that were perfected in evolutionary dissimilar times: in this sense he sort of laid the groundwork for the Triune Brain theory of Paul MacLean.

He also believed that these three evolutionary distinct (logical) components of the human brain were hierarchical in nature and that all that these centers really did was representation of impressions and movements or re-representation of that initial representation (in successively higher centers). He also proposed that lower centers were more simple, more organized, more automatic and more reflexive in nature; while the highest centers were the least automatic, least organized , but the most complex and the least reflex-like in nature.

As these centers evolved one after the other, each such center has a positive function that only it can provide and it also inhibits some of the functions that were earlier provided by the lower layers; or in other words keeps the lower layers in check.

He also believed in the concept of dissolution: whereby when a higher center is not working properly then this would result in the lower centers asserting their autonomy. The loss of the higher layer/ center would not only result in the loss of function associated with that center (negative symptoms) ; but by freeing the autonomic activity of lower center from higher inhibition, it would also lead to some new functions to be experienced (positive symptoms). Thus a dissolution that affects the third or highest layer , would free the intermediate layer to produce some positive effects, and because of unavailability of the higher layer function would also lead to loss of some functionality.

He most fully developed these ideas in association with epilepsy patients, in which he believed, that the epileptiform seizure or discharge leads to inactivity of higher layers (1, 2 or all 3) and inappropriate activity in lower layers, thereby produce different degrees of negative and positive symptoms/ behaviors. My earlier post did contain references to this.

We find evidence for the truth of most of his ideas in today's neuroscience developments.

This time I will like to touch upon how he himself had, sort of extended the triune brain, to an eight stage brain and how he delineated eight different levels of dissolution, each progressively of a more severe level than the earlier one , while he related the concept of dissolution in the Croonian lectures (lecture 1) with the help of movement disorders.

Before we proceed, it is instructive to note that Jackson believed in two levels of consciousness: subject and object- the former related to awareness of impressions; while the latter to movements. In simpler terms , he believed that we could discuss, movement (and volitional) related stuff separate from perceptual stuff and I'll stick to that distinction in this post.

I'll first quote at length from him (I have reformatted the stuff, so please read the original lecture for a balanced view):

I now come to give examples of dissolution. I confess that I have selected cases which illustrate most definitely, not pretending to be able to show that all the diseases of which we have a large clinical knowledge exemplify the law of dissolution. However, I instance very common cases, or cases in which the pathology has been well worked out; they are cases dependent on disease at various levels from the bottom to the top of the central nervous system. Most of them are examples of local dissolution.
  1. Starting at the bottom of the central nervous system, the first example is the commonest variety of progressive muscular atrophy. We see here that atrophy begins in the most voluntary limb, the arm; it affects first the most voluntary part of that limb, the hand, and first of all the most voluntary part of the hand; it then spreads to the trunk, in general to the more antomatic parts. To speak of a lower level of evolution in this case is almost to state a barren truism. At a stage when the muscles of the hand only are wasted, there is atrophy of the first or second dorsal anterior horn; the lower level of evolution is made up of the higher anterior horns for muscles of the arm. This statement, however, is worth making, for it shows clearly that by higher and lower is meant anatomico-physiologically higher or lower.
  2. Going a stage higher we come to hemiplegia, owing to destruction of part of a plexus in the mid-region of the brain. Choosing the commonest variety of hemiplegia, we say that there is loss of more or fewer of the most voluntary movements of one side of the body; we find that the arm, the more voluntary limb, suffers the more and longer; we find, too, that the most voluntary part of the face suffers more than the rest of the face. Here we must speak particularly of the lower level of evolution remaining; strictly we should say collateral and lower. We note that although unilateral movements (the more voluntary) are lost, the more automatic (the bilateral) are retained. Long ago this was explained by Broadbent. Subsequent clinical researches are in accord with his hypothesis. The point of it is that the bilateral movements escape in cases of hemiplegia in spite of destruction of some of the nervous arrangements representing them; the movements are doubly represented—that is, in each half of the brain. Hemiplegia is a clear case of dissolution, loss of the most voluntary movements of one side of the body with persistence of the more automatic movements.
  3. The next illustration is paralysis agitans. Apart from all speculation as to the seat of this disease, the motorial disorder illustrates dissolution well. In most cases the tremor affects the arm first, begins in the hand, and in the thumb and index-finger. The motorial disorder in this disease becomes bilateral; in an advanced stage paralysis agitans is double hemiplegia with rigidity—is a two-sided dissolution.
  4. Next we speak of epileptiform seizures which are unquestionably owing to disease in the midregion of the brain (middle motor centers). Taking the commonest variety, we see that the spasm mostly begins in the arm, nearly always in the hand, and most frequently in the thumb or index-finger, or both; these two digits are the most voluntary parts of the whole body.
  5. . [The next illustration was by cases of temporary paralysis after epileptiform seizures.]
  6. Cborea is a disease in which the limbs (the most voluntary parts) are affected more than the trunk (the more automatic parts), and the arms (the more voluntary limbs) suffer more than the legs. The localization of this disease has not been made out;symptomatically, however, it illustrates dissolution. Chorea has a special interest for me. The great elaborateness of the movements points to disease “high up" —to disease on a high level of evolution. Twenty years ago, from thinking on its peculiarities, it occurred to me that some convolutions represent movements. A view I have taken ever since.
  7. Aphasia. This well illustrates the doctrine of dissolution, and in several ways. We will consider a case of complete speechlessness. (a) There is loss of intellectual (the more voluntary) language, with persistence of emotional (the more automatic) language. In detail the patient cannot speak, and his pantomime is of a very simple kind; yet, on the other hand, he smiles, frowns, varies the tones of his voice (be may be able to sing), and gesticulates as well as ever. Gesticulation, which is an emotional manifestation, must be distinguished from pantomime, which is part of intellectual language. (b) The frequent persistence of “Yes“ and “No“ in the case of patients who are otherwise entirely speechless is a fact of extreme significance. We see that the patient has lost all speech, with the exception of the two most automatic of all verbal utterances. “Yes“and “No“ are evidently most general, for they assent to or dissent from any statement. In consequence of being frequently used, the correlative nervous arrangements are of necessity highly organized, and, as a further consequence, they are deeply automatic. (c) A more important, though not more significant, illustration is that the patient who cannot get out a word in speech nevertheless understands all that we say to him. Plainly this shows loss of a most voluntary service of words, with persistence of a more automatic service of words. We find illustrations in small corners. (d) There are three degrees of the utterance “No“ by aphasics. A patient may use it emotionally only—a most automatic service; another patient may also be able to reply correctly with it—a less automatic, but still very automatic service. (Here there is some real speech.) There is a still higher use of it, which some aphasics have not got. A patient who can reply “No“ to a question may be unable to say ‘No“ when told to do so. You ask the aphasic, “is your name Jones?“ he replies “No.“ You tell him to say “No,“ he tries and fails. You ask, “Are you a hundred years old ?“ He replies “No.“ You tell him to say “No.“ He cannot. Whilst not asserting that the inability to say “No“ when told is a failure in language, it is asserted that such inability with retention of power to use the word in reply illustrates dissolution. (e) A patient who is speechless may be unable to put out his tongue when told to do so; that he knows what is wanted is sometimes shown by his putting his finger in his mouth to help out the organ. That the tongue is not paralyzed in the ordinary sense is easily proved. The patient swallows well, which he could not do if bis tongue were as much paralysed as "it pretends to be.“ Besides, on other occasions he puts out his tongue, for example, to catch a stray crumb. Here is a reduction to a more automatic condition; there is no movement of the tongue more voluntary than that of putting it out when told. [The lecturer then remarked on swearing and on the utterance of other and innocent ejaculations by aphasics, remarking that some of these utterances had elaborate propositional structure but no propositional value. The patients could not repeat, say, what under excitement they uttered glibly and well. He spoke next of the frequent retention of some recurring utterance by aphasics, such as “Come on to me.“ These were not, from the mouth of the aphasic, of any propositional value, were not speech. He had no explanation to offer of these, but stated the hypothesis that they were the words the patient was uttering, or was about to utter, at the time he was taken ill.]
  8. . So far I have spoken of local dissolution occurring on but one half of the nervous system on different levels. Coming to the highest centers I speak of uniform dissolution—of cases in which all divisions of these centers are subjected to the same evil influence. I choose some cases of insanity. In doing this I am taking up the most difficult of all nervous diseases. I grant that it is not possible to show in detail that they exemplify the principle of dissolution, but choosing the simplest of these most complex cases we rnay show clearly that they illustrate it in general. I take a very common-place example—delirium in acute non-cerebral disease. This, scientifically regarded, is a case of insanity. In this, as in all other cases of insanity, it is imperative to take equally into account not only the dissolution but the lower level of evolution that remains. The patient‘s condition is partIy negative and partly positive. Negatively, he ceases to know that be is in hospital, and ceases to recognise persons about him. In other words, he is lost to his surroundings, or, in equivalent terms, he is defectively conscious. We must not say that he does not know where he is because he is defectively conscious; his not knowing where he is is itself defect of consciousness. The negative mental state signifies, on the physical side, exhaustion, or loss of function, somehow caused, of some highest nervous arrangements of his highest centers. We may conveniently say that it shows loss of function of the topmost layer of his highest centers. No one, of course, believes that the highest centers, or any other centers, are in layers; but the supposition will simplify exposition. The other half of his condition is positive. Besides his not knowings, there are his wrong knowings. He imagines himself to be at home or at work, and acts as far as practicable as if he were; ceasing to recognize the nurse as a nurse, he takes her to be his wife. This, the positive part of his condition, shows activity of the second layer of his highest centers; but which, now that the normal topmost layer is out of function, is the then highest layer; his delirium is the “survival of the fittest states,“ on his then highest evolutionary level. Plainly, he je reduced to a more automatic condition. Being (negatively) lost, from loss of function of the highest, latest developed, and least organized, to his present “real,“ surroundings, he (positively) talks and acts as if adjusted to some former “ideal“ surroundings, necessarily the more organized.

This to me seems very promising: I am a die-hard fan of the eight stage evolutionary/ developmental model whereby the first five stages are more similar, the next two on a qualitatively different level; while the last or eighth one takes one a notch higher up the octave to a different qualitative level altogether, although resembling or analogous to the first stage to an extent.

I keep mapping analogies between the different stages evident in different developmental / evolutionary processes and this piece of puzzle fits in nicely.

I'll now like to speculate a bit. I'll first restrict myself to movement/action planning, execution and control. I believe that the regions of the brain involved in this activity are (in a heirarchichal order) :
  1. Frontal Cortex (supplementary motor area) : decides which action to initiate/ plans and co-ordinates with respect to complex actions involving say both hands. More involvement in 'voluntary' actions
  2. Primary Motor cortex : Actual execution of the intended/ chosen action.
  3. Pre-motor cortex:responsible for motor guidance of movements especially with respect to external cues
  4. Parietal cortex:responsible for transforming visual information into motor commands
  5. Somatosensory cortex: this too is involved in motor circuits ; see this too.(synapses to and from this go to cerebellum/ basal ganglia): probably involved in triggering visual information related to the action. I am tempted to replace this with Thalamus and I just might do that after some more research!!
  6. Basal Ganglia: a set of structures that are involved in gross motor control
  7. Cerebellum: a structure involved in fine motor control
  8. Brain Stem: a structure involve in controlling vital involuntary movements like breathing, heart beat etc. these movements are neither voluntary nor automatic; they are involuntary and thus a notch different.
Now coming back to the disorders of the movement delineated by hughlings-Jackson, we can readily see some correspondences. The Basal Ganglia abnormality leading to Huntington's Chorea is clearly at level 6. The primary motor cortex lesion leading to stage 2 hemiplegia is also well established. The epileptofm seizure related spasms and temporary paralysis just after that may be plausibly related to lesions of parietal and somatosnesory cortices. The lesion of pre-motor area may give rise to alien hand syndrome (to be distinguished from Anarchic hand syndrome), whereby you grab any object in sight compulsively. The hughlinghs-jackson description of Parkinsonisms at level 3 does not really gel here as Parkinsonism is more of a basal ganglia problem. Similarly PMA (progressive muscular atrophy) is no longer a valid diagnosis, so it may not map to SMA lesion or dysfunction. SMA dysfunction or lesion may instead produce syndromes like the mirror hand syndrome , in which both hands are used for the same action, though only one hand would have sufficed. It is interesting to note that this mirror hand syndrome is conceptualized today as freeing of SMA inhibition of PMA, thus allowing parallel planning of the same action. Similarly level 7 lesions of cerebellum may be more related to Ataxia rather than aphaisas.

Despite the above problems with the above conceptualization, I find the efforts of Jackson is the right direction and ahead of hist time.

I'll now end with a teaser of things to come. It is related to disorders of phenomenal consciousness classified by Thomas Metzinger in Being No One, and they are as follows :

Deviant phenomenal models of reality
  1. Agnosia
  2. Neglect
  3. Blindsight
  4. Hallucinations
  5. Dreams
To me they follow the same 5 stage process, with each stage analogous to the movement related disorder.More about that later.

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Friday, September 05, 2008

Intentionality: order, order!

I have been reading, of late, some articles that have invoked the concept of intentionality and its orders. More specifically, this has been with respect to Social Brian hypothesis of Robin Dunbar, whereby he claims that humans evolved intelligence to be able to cope with your in-laws (and other social members of one's groups). Leaving asides the main premise of the social brain hypothesis, which I find convincing to an extent, he also claims that monkeys have only first order intentionality, while apes have second order and humans are able to function at about fifth order of intentionality, with some like Shakespeare being able to work on the sixth order. To quote at length form the 'beginner's guide to intentionality':

Computers can be said to know things because their memories contain information; however, it seems unlikely that they know that they know these things, in that we have no evidence that they can reflect on their states of ‘‘mind.’’ In the jargon of the philosophy of mind, computers are zero-order intentional machines. Intentionality is the term that philosophers of mind use to refer to the state of having a state of mind (knowing, believing, thinking, wanting, understanding, intending, etc).

Most vertebrates are probably capable of reflecting on their states of mind, at least in some crude sense: they know that they know. Organisms of this kind are first-order intentional. By extension, second-order intentional organisms know that someone else knows something, and third-order intentional organisms know that someone else knows that someone else knows something. In principle, the sequence can be extended reflexively indefinitely, although, in practice, humans rarely engage in more than fourth-order intentionality in everyday life and probably face an upper limit at sixth-order (‘‘Peter knows that Jane believes that Mark thinks that Paula wants Jake to suppose that Amelia intends to do something’’).

A minimum of fourth-order intentionality is required for literature that goes beyond the merely narrative (‘‘the writer wants the reader to believe that character A thinks that character B intends to do something’’). Similar abilities may be required for science, since doing science requires us to ask whether the world can be other than it is (a second-order problem at the very least) and then ask someone else to do the same (an additional order of intentionality).


I find the above definitions (and other I have found on the web), slightly problematic, so I'll attempt my own synthesis on the matter:

  1. Zeroth order or No intentionality: Having knowledge but no 'awareness ' of knowledge. Mere representation of information, but no meta awareness of that representation. Computers and machines , and even simple life forms like bacteria etc, may have this (no) intentionality, wherein they have 'facts' about the world, but no beliefs, desires etc.
  2. First Order Intentionality: Awareness of knowledge that is distinct from mere knowledge. A belief system. Knowing that something you know may be incorrect from the actual world scenario. You know what you know and you know what you don't know. Meta cognition. Beliefs, desires etc. Important thing to note is that only 'I know' is covered in this definition. A limited 'You know as I know' may be covered at this order as one may be aware of other people as being intentional agents , but whose beliefs are congruent with one's own! 'You know something that may be different from what I know' is not possible yet. Most mammals including rats and monkeys are at this level. Awareness ta this level may be that others too have facts of world at their disposal.
  3. Second order intentionality: Awareness of a belief-system that is distinct from the belief system itself. A Theory of Mind. You know that someone else may know things differently from both as they are and as you think they are. Awareness that others have a mind or a belief-system. Ability to keep two different belief systems in the mind- one of your own and the other of another third person. Apes and children age 4 demonstrate this level and order of intentionality. They have a theory of mind as to the fact that others have beliefs and that these are after all beliefs and can be false too. Awareness that others have beliefs, but still no awareness that they have a ToM too!
  4. Third order intentionality: Awareness of a ToM that is distinct from the ToM itself. A communicative intent. Joint attention. Language. symbol grounding. Knowing that someone else may have different views regarding what you yourself believe and thus it is important to communicate your internal intentions, beliefs , desires etc to others so that there is common ground on which communication and speech acts can proceed. this also enables grounds for lies and deceptions in the sense that one can deliberately lead someone to believe what one oneself does not believe. As per this source , communication requires third order of intentionality. To quote:

  5. Suppose my little brother intends for me to jump. He might (and sometimes does) achieve this by sneaking up behind me and yelling "Boo!". But that's not communication, in the fullest sense of the word. It would be quite a different sort of action were he to instead request of me, "please jump." (I don't think he'd find that nearly so fun, for one thing.) Such a speech-act would show not only that he intends me to jump, but also that he intends for me to recognize that he wants me to jump.

    Purposive communication requires an intentional state of at least third-order complexity. The speaker wants his audience to recognize what the speaker intends by his utterance. Put another way, you don't just communicate 'X', you rather communicate, "I am trying to convey 'X'". (This is the difference between discreetly insulting someone, or making it clear to him that you want him to know you're insulting him.) Anything less would fail to qualify as 'communication', in the fullest sense of the word.

  6. Fourth-order Intentionality: Awareness of a communicative act that is distinct from the communicative act itself: A narrative or story telling/ story understanding capability. An ability to weave experiences into a running narrative such that it incorporates different communicative acts or 'scenes'. An understanding of 'roles' that one is playing that give shape to all the communicative acts one participate sin and the narrative one weaves for oneself. A limited awareness that others are also communicative agents , but not a full awareness , that like oneself, they are also acting a script/ playing a role/ having a running narrative using which they interpret events. It is important to emphasize that story telling requires one to visit a new world in which the protagonist is separate, but also one is in a state of willful suspension of disbelief and thus one feels along-with the protagonist, but still retains one's own narrative: separate, and quite distinct, form the story-teller's narrative. Story-telling, and story understanding and the interpreter module of humans that gives rise to stream of consciousness to me are the hallmarks of fourth order of intentionality and most of us juts stop there. One may mistakenly believe that there is only one role / narrative and that everybody shares the same narrative.
  7. Fifth order intentionality: Awareness of roles and narratives that are distinct from the role or narrative. An organizing system of religion/ myths using which one interprets stories. Awareness that others too have their own narratives and are playing a script/ performing their roles. Awareness that one's role/ stance / understanding of world can be radically different from someone having the same experiences but using a different interpretation. A culture . A worldview. It is instructive to note that Dunbar considers that religion and story telling are higher level intentional activities.
I'll leave things as they are for now as this fits nicely with my obsession with 5 + 3 stage developmental process. Higher orders of intentionality may exist, but probably we humans are not yet evolved to appreciate their subtleties/ find practical examples.

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Thursday, September 04, 2008

Love and bond

The blogosphere and the news tabloids are abuzz with the latest discovery that Vasoprassin may serve a similar role in humans as it does in prairie voles, when it comes to pair bonding. While , it might be true that 'if you love someone , set him free' a more strategic and evolutionary sound strategy is to keep him bound in a pair-bond. The females do this, by somehow , releasing Vasporossin in their partners brain and when this vasporossin binds to its receptors in the Brain, it leads to more bonding and pro-social behavior by the male.  


A recent PNAS paper has implicated the vasoprassin receptor gene alleles for some variation in the marital bond. Read the excellent Not Exactly Rocket Science post for more details. Interestingly the gene variant , while conferring lower marital bond probability, also ups the risk for Autism. The mechanism underlying this must therefore be social - as social difficulties in Autistics may be related to this. This leads to the interesting hypothesis that people with Psychosis may have a stronger version o this pair-bonding receptor gene and thus may be less prone to depart ways, once a pis bond has been formed, and this may explain why despite low chances for procreation, the genes for schizophrenia may be carried out as the limited number of offspring's are more heavily invested in by parents due to a stable pair bond.


But I digress, let this Post be about Love and what better way to celebrate that with a 'Prairie voles in Love' poem by Scicurious!


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Monday, September 01, 2008

Oligodendrocytes, Homunculus and surgery for Epilepsy

Guess what each of them have in common? While the discovery of oligodendrocytes was a result of painstaking cyto-architectural efforts of Dr. Penfield, the Montreal procedure he developed, which involved probing the brain areas around the tumor to be removed, also paved the way for the 'scientific phrenology' whereby the sensory and motor (and other areas too eventually) areas were mapped and gifted us with the Homunculus. If you, like me, were unaware of the oligodendrocytes link with Penfield, you may find Neurophiliosophy post on Penfield fascinating. Even if you knew this fact, do checkout the excellent profile of Dr. Penfield, and discover how he is connected to the who's who of Neuroscience- from Hughlinghs Jackson to Donald Hebb. An excellent article indeed and one that will definitely find place in the Open Lab 2008.

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Thursday, August 28, 2008

Overcoming the Monster- Indian style!

Thanks to Vaughan, I spent a greater time of my day researching the 'basic plots' that are behind all good stories. Regular readers of this blog, would know that I am a sucker for 'five basic' or 'eight basic' anything (with a variation that 'seven basic' is also accommodated as, as per my theory the eighth basic may be on a different qualitative level and thus likely to be missed!

The original Mind Hacks post was regarding Levitin's new book that claims that there are only six basic types of songs: Friendship, Joy, Comfort, Knowledge, Ceremony/religion/ritual and Love, but I strayed from the main course and started savoring the eight basic dramatic plots served by Dennis Johnson: Cinderella, Achilles, Faust, Tristan , Circe, Romeo&Juliet, Orpheus and the Irrepressible Hero (The FOOL anyone?) (all but the last named after famous characters). It wasn't long before I was reading 'The Seven Basic Plots' by Christopher Booker.

The seven basic plots Booker outlines are : Overcoming the Monster, Rags to Riches, The Quest, Voyage & return, Comedy, Tragedy and Rebirth. while I'll most probably write more on the topic after reading the whole book , I would like to comment now on the first plot: 'Overcoming the Monster' .

In this, typically a Hero is pitted against a monster, whom he slays to win a princess/ treasure / kingdom etc. While reading this plot, two famous Lord Krishna myths immediately flashed before me:

The first is the myth of how Satrjit's Mani (pearl) came in possession of Jambvant and how Krishna fought and defeated Jambvant to defend himself from the false theft accusation of the pearl. Now this is no 'traditional' overcoming the monster myth as Jambvant is no monster- rather he is a revered chiranjivi being. Also, Jambvant is not killed, but gracefully withdraws from the fight after realizing the 'god' nature of Krishna. Howvere, like traditional 'overcome the monster' plot, there is treasure guarded and a princess (Jambvati , the daughter of Jambvant) married after the defeat. This time another princess (two marriages!) Satyabhama, who is the daughter of the King Satarjit, is also married to Krishna. Krishna, of course doesnt take the pearl (treasure) buts ends up with two wives! So some form of the plot is there, but not in its entirety. Also, the whole narrative is pre-ordained as Krishna saw moon during inauspicious time, so the take home is that there is no real evil or fight involved - it is all Maya or illusion!!

The second 'overcoming the monster' myth is again from Krishna myth. This time the monster is indeed really monstrous-a big, venomous serpent called Kaliya, and like traditional story the kingdom and the common people are troubled by this serpent; but in this case also no death of Kaliya is involved: he is just tamed and sent to a different place; also it seems Kaliya was there because of fear of Garuda, so again Kaliya per se is not 'really ' evil and all is Maya.

I like this circularity and 'fictional maya-like' view of things of Indian culture very much and I am sure the other plots would also have been similarly adapted by Indians: circular and without any 'real' 'evil' lurking around.

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Friday, August 22, 2008

Exploration/ Exploitation == Maximisers/ Satisficers?

There is an interesting research coverage at We are Only Human blog regarding whether people may have two different cognitive styles- one based on exploration of novel ideas and the other based on exploitation or focus on a particular familiar idea. The study employs evolutionary concepts and theorizes that these different cognitive styles may be a reflection of the different foraging styles that might have been selected for and relevant in EEA.

Specifically, while foraging for food in a habitat where the food supply and resources are unpredictable , one is faced with a choice when one has discovered a food source: whether to exploit this food source (a jungle area having sparse edible leaves) or to move ahead in search of a potentially better food source (a jungle area having abundant edible and nutritious fruits) . Both strategies , that of exploring or exploiting can be advantageous and may have been selected for. It is also possible that humans can use either of the strategies based on the environment- (food source distribution) , but may be inclined towards one strategy or the other. The authors of the study surmised that both the strategies have been selected for and we have the potential to use either of the strategy. Moreover, the same foraging strategy we use or are primed of, would also be visible in the cognitive strategy we use.

They used an ingenious technique to prime the subjects with either of the foraging strategies (go read the excellent We are only human blog post) and found that humans were flexible in the use of the appropriate strategy, given the appropriate context, and that the foraging strategy primed the corresponding cognitive strategy. To boot, those primed with an exploratory foraging strategy would be more prone to using exploratory cognitive strategies when confronted with a cognitive task and vice versa. They also found systematic differences between individuals cognitive and foraging styles- some were more exploratory than the others.

This reminds me of the Maximizers/ Satisficers distinction in decision-making style that Barry Scwatrz has introduced and brought to public attention. Basically a Maximizer , when faced with a decision and choice, would go on computing the utility of different choices and try to choose the option that maximizes his utility and is the 'best'. A Satisficer, on the other hand would also explore options, but stop his exploration, when he finds an option that is 'good enough'. I wonder, if just like the exploratory/ Exploitative cognitive and foraging styles, this is just another dimension of the same underlying phenomenon- whether to explore more - or to exploit what is available. To take an example, for marriage, a satisficing strategy may work best - as told in "The Little Prince" one should stop searching for more flowers if one has already had the fortune of possessing a flower.


"People where you live," the little prince said, "grow five thousand roses in one garden... yet they don't find what they're looking for..."

"They don't find it," I answered.

"And yet what they're looking for could be found in a single rose, or a little water..."


An interesting experiment would be to see, if the foraging style, the cognitive style, and the decisions style are all correlated within individuals and if priming one can influence the outcome of the other style.

If so, could there be an underlying neural phenomenon , common to all?

Wray, the author of We are only human blog makes a bold conjecture and relates this to the finding that dopamine levels.

Exploratory and inattentive foraging—actual or abstract—appears linked to decreases in the brain chemical dopamine.


He even relates this to cognitive disorders like Autism and ADHD.

By analogy, in conditions where baseline dopamine is more, like in bipolar and psychosis, one may be more inclined to a more staisficing/ 'I'm feeling Lucky' strategy in which the very first option is acceptable. This may explain the 'jumping-to-conclusions' bias in schizophrenia/ psychosis.

To make things more explicit, though the leading dopamine theory in vogue now is of 'error-prediction' , a competing, and to me more reasonable, view of dopamine function is incentive salience i.e. what 'value'/ importance does the stimuli have for the person in question. The importance can be both positive and negative and thus we have found that dopamine is involved in both dread and desire. The dominant reward prediction theory faces many challenges, the least of which is response of dopamine neurons to novel events. A dopamine burst is also associated with 'novel' events and thus dopamine is somehow involved in/ triggered by Novelty. Baseline dopamine may constrain the dopamine surge felt on a novel event. Thus, in schizophrenia/ psychosis , with baseline dopamine high, a dopamine burst on novelty detection may be high enough so that it is meaningful and may not lead to more exploratory behavior. While in the disorders where baseline dopamine is low, one may require a more profound dopamine burst before the stimuli becoming meaningful and thus may go on seeking novel stimulus till one finds one 'big enough to trigger salience'.

We may extend the salience argument to other domains than incentive. If the chief function of dopamine is to mark salience, then it may also be instrumental in memory and attention. Only what is Salient gets attention, and only what is salient gets into Working Memory. Thus,a high dopamine level may predispose to treating almost everything as salient, leading to delusions of reference (everything is meaningfully related to self etc) etc. Working Memory may be taxed due to everything trying to get in- and thus poor WM in people with schizophrenia. Also, every trivial thing may grab attention- leading to poor sensory gating and conditions like lack of pre-pulse inhibition. On the flip side, while making sense of ones experience, one may accept the first possible explanation and do not search further - thus leading to persistence of delusions.

An opposite scenario would be when one keeps exploring the environment and nothing seems novel due to low dopamine levels. This would be the classical Autistic repetitive and stereotype behaviors. There would be sensory over stimulation, as nothing is salient and one needs to explore more and more. On the other hand, WM capabilities may be good/ savant like, as not every piece of information grabs attention. Everything should seem insignificant and the only way to arrive at decision / choose action would be via exhaustive enumeration and logical evaluations of all options. even after obvious explanations for phenomenon, one may keep looking for a better explanation. No wonder , as per my theory, more scientists would be autistic.

Perhaps, I am stretching things too far, but to me the dopamine connection to Salience/ Meaning/ Importance is sort of worth exploring and I will write more about that in future. For now, let us be willing to associate Salience not just with stimuli related to motivation, but also with stimuli relevant in sensation, perception,learning and memory. If so the common underlying mechanism responsible for differentiating us as a exploratory and expolitatory forager (food) may also be related to our different cognitive styles, our different decision-making styles and our different baseline dopamine levels.

Dopamine though is most strongly related to food and sex. I could even stretch this argument and say this may be related to r and K reproductive styles (note these styles are species specific, but I believe individuals in a specie may also vary on the reproductive strategy along this dimension). Thus, while explorers may have r type of reproductive style, the exploiters may have a K reproductive style.

At one extreme are r-strategies, emphasizing gamete production, mating behavior, and high reproductive rates, and at the other extreme are K-strategies, emphasizing high levels of parental care, resource acquisition, kin provisioning, and social complexity.


If K-strategy is what humans have chosen, maybe exploitation in all areas (cognitive, decision-making, foraging) is more relevant and in tune with our nature. Maybe that's why I'll always be on the side of Psychosis than Autism!! Though, to put things in perspective, maybe humans have evolved to use both strategies as the situations demands , and the best thing would be to use the strategy situation-specific and not lean towards either extremes.

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Tuesday, August 05, 2008

Top 100 cutting edge science blogs!

A top 100 cutting edge science blogs list has been compiled by X-Ray Technician Schools and includes a host of good science blogs. Some I already knew and some are new to me. It is a must-visit for every science buff who is interested in cutting edge science and would like to increase the number of good science blogs that one regularly monitors/ reads.

The list is broken up into categories and there are categories like Health and Biology; a category that is conspicuously missing is psychology/neuroscience, but you can find many good blogs related to psychology/neuroscience in that list, so do take a look.

I would also like to thank the hosts for featuring The Mouse Trap blog in that list and hope that this blog lives up to the expectations and does retain its cutting edge focus!

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