Some rambling on "Selves" and "Purpose"

The recent posts on Alwyn Scott and the Blakesless' book prompt me to this random walk....

Self conscious "Purpose" of the sort we humans experience, in the service of crafting new political movements or environments, is an evolved psychology that (sometimes) helps pass on our genes, and requires our distinctively human self reflective "I". Our behavior and that of other animals also reflects a kind of purpose that has been formed by our evolutionary and developmental history. In other animals such behaviors are acted out on the cusp of an eternal present - there is no evidence that they "know that they know" in the way that we can.

Both modern neuroscience (cf. the quote from the Blakesless' book) and Buddhist psychology inform us that the self and the purpose that each of us experiences is an illusion or confabulation of our brains - hopefully a useful one - whose utility is tested by how it enhances our energy and individual survival. This 'illusion' is a powerful instrument of downward causation, regulating our psychological, immune, neuro-endocrine robustness.

What is especially amazing is that our human body/brain can sometimes use meditative or other techniques to bootstrap to a level of metacognition that rests antecedent to - and can be the detached observer of - the generation of this illusion of a self and its purposes.

The maximum power of our self illusion, for most of us, goes with our heartfelt immersion and belief in it (i.e., our delusion). From such a immersion, it can be more difficult to discern or appreciate the different selves and purposes of other humans, and their cultures and historical eras.

Rich and Poor

San Paulo, Brazil.

Playing Action Video Games Reduces Gender Differences in Spatial Cognition

From Feng, Spence, and Pratt (PDF here):

We demonstrate a previously unknown gender difference in the distribution of spatial attention, a basic capacity that supports higher-level spatial cognition. More remarkably, we found that playing an action video game can virtually eliminate this gender difference in spatial attention and simultaneously decrease the gender disparity in mental rotation ability, a higher-level process in spatial cognition. After only 10 hr of training with an action video game, subjects realized substantial gains in both spatial attention and mental rotation, with women benefiting more than men. Control subjects who played a non-action game showed no improvement. Given that superior spatial skills are important in the mathematical and engineering sciences, these findings have practical implications for attracting men and women to these fields.

From their article:

The experimental group was trained using Medal of Honor: Pacific Assault, which was chosen because it is similar to the games typically played by players in Experiment 1 [note: which compared students based on their self reports of game use] and because it has been used before in attention training studies. This game is a 3-D first-person shooter game that requires intense visual monitoring and attentional resources. The control group played Ballance, a 3-D puzzle game that involves steering a ball through a hovering maze of paths and rails with obstacles such as seesaws, suspension bridges, and pendulums.

Plasticity and learning in the human mirror neuron system

I pass on a review by Welberg of an interesting study by Catmur et al. [Catmur, C., Walsh, V. & Heyes, C. Sensorimotor learning configures the human mirror system. Curr. Biol. 17, 1527–1531 (2007)]:

Neurons in the frontoparietal mirror system fire when one performs an action and when one observes someone else performing that same action. This system is thought to have a role in social cognition and, perhaps, in language acquisition. How the mirror neurons map sensory input onto its motor representation is unknown, but Catmur et al. demonstrate that these representations are not innate and can be altered by training.

The authors used transcranial magnetic stimulation (TMS) to stimulate the motor cortex of volunteers who were watching a video of a hand. When the volunteers watched the hand's index finger move, the TMS-induced motor-evoked potential (MEP) was greater in the abductor muscle of their own index finger than when they watched the little finger move; conversely, the MEP of their little finger's abductor muscle was greatest when they watched the little finger move. In other words, a muscle showed MEP enhancement when its owner watched a movement that is normally performed by that muscle; this 'mirror effect' is thought to reflect activity of the mirror neuron system.

Half of the volunteers then underwent incongruent training trials, in which they were asked to extend their little finger if the video showed a hand extending the index finger, and vice versa. People in congruent trials simply had to repeat the movement they saw in the video. The incongruent trials were assumed to train the mirror system to associate an observed finger movement with movement of a different finger of the volunteer's own hand.

Measuring TMS-induced MEPs after training, the authors found that volunteers who had undergone the incongruent training now showed greater MEPs in the muscle of one finger when watching the 'wrong' finger move in the video, indicating that a reversal of muscle-specific MEP enhancement during action observation had taken place.

This study shows that the 'mirror properties' of the mirror system are not innate. Rather, they can be trained, through sensorimotor experience, to transform observation into action. These findings imply that insufficient social interaction and consequent inadequate sensory experience might affect the development of the mirror neuron system, for example, in children with autism.

New research on ageing

Nature Magazine offers a special open access supplement with several excellent articles on recent research on ageing. Also, they offer to send a free print copy.

Striking Images....

Here are the first place winners of Science Magazine's 2007 Visualization Challenge, in which editors evaluate submissions that try to bring scientific data to life through images, illustrations, computer graphics, and animations. In the first, 182 thin CT "slices" are stacked together to create a 3D image looking upward at the sinuses from underneath the head. In the second, Irish ocean moss is spread out for photography.

How Meaning Shapes Seeing

This is the title of an interesting article by Koivisto and Revonsuo in Psychological Science. They show that semantic meaning influences inattentional blindness. Here is their abstract:

Inattentional blindness refers to the failure to see an unexpected object that one may be looking at directly when one's attention is elsewhere. We studied whether a stimulus whose meaning is relevant to the attentional goals of the observer will capture attention and escape inattentional blindness. The results showed that an unexpected stimulus belonging to the attended semantic category but not sharing physical features with the attended stimuli was detected more often than a semantically unrelated stimulus. This effect was larger when the unexpected stimuli were words than when they were pictures. The results imply that the semantic relation between the observer's attentional set and the unexpected stimulus plays a crucial role in inattentional blindness: An unexpected stimulus semantically related to the observer's current interests is likely to be seen, whereas unrelated unexpected stimuli are unseen. Attentional selection may thus be driven by purely semantic features: Meaning may determine whether or not one sees a stimulus.

Different cognitive processes underlying human mate choices and mate preferences

Starting with the assumption that the underlying function of mate choice is reproductive success, evolutionary psychologists have proposed that men should seek young, fertile, faithful women, and women should seek high-status, resourceful, committed men. This evolutionary reasoning predicts what traits people will actually tend to choose, but not necessarily what people say they will (or would like to) choose. Todd et al. suggest that different cognitive processes underlie mate preferences and actual human mate choices. Here is their abstract:

Based on undergraduates' self-reports of mate preferences for various traits and self-perceptions of their own levels on those traits, Buston and Emlen [Buston PM, Emlen ST (2003) Proc Natl Acad Sci USA 100:8805–8810] concluded that modern human mate choices do not reflect predictions of tradeoffs from evolutionary theory but instead follow a "likes-attract" pattern, where people choose mates who match their self-perceptions. However, reported preferences need not correspond to actual mate choices, which are more relevant from an evolutionary perspective. In a study of 46 adults participating in a speed-dating event, we were largely able to replicate Buston and Emlen's self-report results in a pre-event questionnaire, but we found that the stated preferences did not predict actual choices made during the speed-dates. Instead, men chose women based on their physical attractiveness, whereas women, who were generally much more discriminating than men, chose men whose overall desirability as a mate matched the women's self-perceived physical attractiveness. Unlike the cognitive processes that Buston and Emlen inferred from self-reports, this pattern of results from actual mate choices is very much in line with the evolutionary predictions of parental investment theory.

Cortical evolution and skilled hand use.

Unlike other New World species, such as squirrel monkeys, that exclusively use a power grip, cebus monkeys frequently use a precision grip in which the thumb and forefinger are brought into contact with one another to manipulate small objects, or engage in goal-directed tool use. Such a precision grip is observed in many old world monkey species, such as the macaques. Padberg et al. find:

..Unlike other New World Monkeys, but much like the macaque monkey, cebus monkeys possess a proprioceptive cortical area 2 and a well developed area 5, which is associated with motor planning and the generation of internal body coordinates necessary for visually guided reaching, grasping, and manipulation.

This is an example of parallel evolution:

...The similarity of these fields in cebus monkeys and distantly related macaque monkeys with similar manual abilities indicates that the range of cortical organizations that can emerge in primates is constrained, and those that emerge are the result of highly conserved developmental mechanisms that shape the boundaries and topographic organizations of cortical areas.

Left, Primate cladogram showing which primate taxa have the following characteristics related to manual control: complex manipulation (e.g., grasping food with one hand and peeling it with the other), use of feeding tools, corticospinal (CS) terminals in ventral horn (VH), opposable (or laterally opposable) thumb, and presence of parietal area 2. Filled box, Characteristic is present. Unfilled box: characteristic has been sufficiently tested and is absent. Right, Parietal areas and representative grasp postures traced from photographs in five primate species.
[Note: pink and green indicate areas 2 and 5 mentioned above.)

Stairways to the Mind

Alwyn Scott passed away recently. "Stairways to the Mind" was one of his books, on levels of organization and emergent properties. I knew him when he was at Wisconsin, and later read a copy of this book in draft form, to offer comments. In looking back over his work, I came across a review of the book written by Willis Harman, one of the founders of the Noetic Sciences Institute, which included a mild criticism that I don't completely agree with, but thought interesting:

Having gone so far in urging the usefulness of a hierarchical structuring of science, and having recognized (with Roger Sperry) that the consciousness level can be causal with regard to the biological or physical level (as well as the reverse), it seems a pity not to have gone one step further to recognize that the new disciplines of transpersonal psychology and anthropology, and the deepest insights of artists and mystics, can fit quite comfortably within the top level of the hierarchy. The metaphysical insight that the material world evolves within consciousness can live side by side with the complementary metaphor of consciousness as emergent from the physical.

Self-Referential Cognition in Autism

Individuals with autism spectrum conditions (ASC) have profound impairments in the interpersonal social domain, but it is unclear if individuals with ASC also have impairments in the intrapersonal self-referential domain. Lombardo et. al. give an interesting introductory discussion of the "absent self" model of Frith. They then evaluate performance of 30 subjects and:

"conclude that individuals with ASC have broad impairments in both self-referential cognition and empathy. These two domains are also intrinsically linked and support predictions made by simulation theory. Our results also highlight a specific dysfunction in ASC within cortical midlines structures of the brain such as the medial prefrontal cortex."

Figure:. Image showing the overlap in peaks of activation from studies of self-referential cognition, other-referential cognition, and theory of mind within the medial prefrontal cortex and posterior cingulate/precuneus.

Boundaries are 16mm from within midline. All peaks are taken from exemplary studies in the literature. Brain is depicted on a representative sagittal slice of the Montreal Neurological Institute (MNI) template

Brain correlates of different spatial learning strategies

Each of us tends to emphasize one of two main strategies for spacial navigation. Learning the relationships between environmental landmarks using a "spatial memory strategy" to construct a cognitive map depends on the hippocampus. Navigating using a "response strategy", or series of turns at precise decision points (turn left at corner, then turn right at...), involves the caudate nucleus and proceeds without using landmark relationships. Bohbot et al. have used a virtual maze task to examine 50 young healthy subjects, half reporting the use each strategy. Those using the spatial strategy

...had significantly more gray matter in the hippocampus and less gray matter in the caudate nucleus compared with response learners. Furthermore, the gray matter in the hippocampus was negatively correlated to the gray matter in the caudate nucleus, suggesting a competitive interaction between these two brain areas.

In a second analysis:

.. the gray matter of regions known to be anatomically connected to the hippocampus, such as the amygdala, parahippocampal, perirhinal, entorhinal and orbitofrontal cortices were shown to covary with gray matter in the hippocampus. Because low gray matter in the hippocampus is a risk factor for Alzheimer's disease, these results have important implications for intervention programs that aim at functional recovery in these brain areas. In addition, these data suggest that spatial strategies may provide protective effects against degeneration of the hippocampus that occurs with normal aging.

Ape language slips reveal category knowledge storage.

Michael Erard summarizes efforts (PDF here) to analyze 'language' errors of apes for insight into the covert mental processes of animals - analogous to such work done on human language errors He focuses on the work of Lyn, who was the first to apply the study of errors to bonobos . Kanzi and a female bonobo, Panbanisha, who now live at the Great Ape Trust in Des Moines, Iowa, can comprehend instructions and descriptions in spoken English, and they can respond by using 384 lexigrams, which they touch on a keyboard.

Lyn found that Kanzi and Panbanisha have arranged hundreds of lexigrams in their minds in a complex, hierarchical manner based mainly on their meaning. She coded the relations between all 1497 sample-error pairs along seven dimensions, including whether the lexigrams looked alike, had English words that sounded alike, or referred to objects in the same category. She found that the errors were not random but patterned. If the lexigram stood for "blackberry," the error was more likely than chance to sound like blackberry, be edible, be a fruit, or be physically similar. Errors were also more likely to be associated with more than one category. For example, "cherries" are both edibles and fruits, and the word sounds like the correct one, "blackberries." All this indicated to Lyn that mental representations of the lexigrams must be stored not as simple one-to-one associations but in more complex arrangements. This suggests that, given the chance, bonobos and other apes can acquire systems of meaning that are closer than anyone has thought to what humans do, and that some aspects of language acquisition are not unique to humans.

Symbiosis of human brains and the web...

George Johnson notes that the web has stripped the word algorithm (a recipe for solving problems step by step) of its innocence. The algorithms used by Google search, Amazon, MySpace, etc. perform an intelligence amplification, leveraging human thinking with machines in the service of selling more goods. The boundary between human and computer responses increasingly blurs. Submit or change a Wikipedia article and "a swarm of warm- and sometimes hot-blooded proofreading routines go to work making corrections and corrections to the corrections." Here is the PDF of Johnson's article.

Moral Universals

Nicholas Wade offers a summary (PDF here) of some of the evidence that humans have an evolved moral intuition that appeared before the development of language. (This has been the subject of several previous blog posts), focusing on the views of Jonathan Haidt. Haidt suggests that there are five innate moral systems, or rather, innate psychological mechanisms that predispose children to absorb certain virtues. Some concern the protection of individuals, others the ties that bind a group together. Of the moral systems that protect individuals, one is concerned with preventing harm to the person and the other with reciprocity and fairness. Less familiar are the three systems that promote behaviors developed for strengthening the group. These are loyalty to the in-group, respect for authority and hierarchy, and a sense of purity or sanctity.

A striking demonstration comes from experiments that show that people will say it is morally acceptable to pull a switch that diverts a train, killing just one person instead of the five on the other track. But if asked to save the same five lives by throwing a person in the train’s path, people will say the action is wrong. This may be evidence for an ancient subconscious morality that deters causing direct physical harm to someone else. An equally strong moral sanction has not yet evolved for harming someone indirectly.

Emotion and Disorders of Emotion

You might want to check out this open access special focus issue of Nature Magazine on emotion and disorders of emotion. The starting editorial introduces the articles. Individual susceptibility to depression and anxiety in response to life stressors may be related to genetic variation, and I would point to the review article by Klaus-Peter Lesch and Turhan Canli. It explores how individual variation in the serotonin transporter gene may interact with personality, emotion regulation and social cognition.

Prospection: simulation of future unique to humans

Gilbert and Wilson offer a concise review of our unique human ability to simulate the future, covering brain regions involved and stereotyped errors that occur (PDF here). (I did a series of posts in June, 2006 abstracting Gilberts book "Stumbling on Happiness." You can use the blog search box to find them by entering the word "stumbling.") Here are some clips:

Prefeelings will be reliable predictors of subsequent hedonic experiences when two conditions are met. As the figure shows, when we are in the present (T₁) attempting to predict our hedonic reaction to an event in the future (H₂), our present hedonic experience (H₁) is influenced by our simulation of the future event (e₁) as well as by contextual factors (₁), such as the events that are occurring in the present, the thoughts we are having in the present, our present bodily states, and so on. We feel better when we imagine going to the theater than to the dentist, but we feel better imagining either event on a sunny day than on a rainy day, or when we are well rather than ill. Similarly, our future hedonic experience (H₂) will be influenced both by our perception of the event (e₂) and by contextual factors (₂). Because our hedonic experiences are influenced both by our mental representation of the event and by contextual factors, our present hedonic experience will be a reliable predictor of our future hedonic experience if and only if (i) our simulation of the event at T₁ exerts the same influence on our hedonic experience at T₁ as our perception of the event at T₂ exerts on our hedonic experience at T₂, and (ii) contextual factors at T₁ exert the same influence on our hedonic experience at T₁ as contextual factors at T₂ exert on our hedonic experience at T₂. In other words, H₁ = H₂ if and only if e₁ = e₂ and ₁ = ₂. Errors in prospection arise from the fact that people use their prefeelings to make hedonic predictions even when one or both of these conditions is not met. These errors are of four kinds.

Simulations are unrepresentative. We naturally imagine our next dental appointment by remembering our last one.... research suggests that people often use unrepresentative memories as a basis for simulation. For example, when people who have missed trains in the past are asked to imagine missing a train in the future, they tend to remember their worst train-missing experience rather than their typical train-missing experience.

Simulations are essentialized. When we imagine "going to the theater next week," we don't imagine every detail of the event, but rather, we imagine the essential features that define it. We imagine seeing a stage filled with actors but we do not imagine parking the car, checking our coat, or finding our seat. The problem with omitting inessential features from simulations is that such features can profoundly influence our subsequent hedonic experience... Because simulations omit inessential features, people tend to predict that good events will be better and bad events will be worse than they actually turn out to be. The young couple who simulate the joys of parenthood but fail to simulate the drudgery of diapers are unlikely to have the hedonic experience they imagined.

Simulations are abbreviated. If we imagined each and every moment of the events we were simulating, our simulations would take as long as the events themselves. Simulations are naturally abbreviated and represent just a few, select moments of a future event. The moments they select tend to be the early ones. When people imagine what their lives would be like if they won the lottery or became paraplegic, they are more likely to imagine the first day than the two-hundred-and-ninety-seventh. The problem with imagining only the early moments of an event is that hedonic reactions to events typically dissipate over time, which means that mental simulations tend to the moments that evoke the most intense pleasure or pain.

Simulations are decontextualized. Research shows that people often do not consider the potentially significant differences between contextual factors at T1 and T2 when using their present hedonic state to predict their future hedonic state. For example, hungry people mistakenly expect to like eating spaghetti for breakfast the next day, and sated people mistakenly expect to dislike eating it for dinner the next day. People who have just exercised mistakenly expect to enjoy drinking water the next day more than do people who are about to exercise (53). In both cases, people do not seem to realize that their present hunger and thirst are influencing their hedonic reactions to simulated future consumption. They ignore the fact that the contextual factors that are presently exerting an influence at T1 (i.e., hunger and thirst) will not exert the same influence at T2.

Their conclusion makes a nice summary of how modern and ancient brain systems interact in imagining possible future feelings:

Mental simulation is the means by which the brain discovers what it already knows. When faced with decisions about future events, the cortex generates simulations, briefly tricking subcortical systems into believing that those events are unfolding in the present and then taking note of the feelings these systems produce. The cortex is interested in feelings because they encode the wisdom that our species has acquired over millennia about the adaptive significance of the events we are perceiving. Alas, actually perceiving a bear is a potentially expensive way to learn about its adaptive significance, and thus evolution has provided us with a method for getting this information in advance of the encounter. When we preview the future and prefeel its consequences, we are soliciting advice from our ancestors.

This method is ingenious but imperfect. The cortex attempts to trick the rest of the brain by impersonating a sensory system. It simulates future events to find out what subcortical structures know, but try as it might, the cortex cannot generate simulations that have all the richness and reality of genuine perceptions. Its simulations are deficient because they are based on a small number of memories, they omit large numbers of features, they do not sustain themselves over time, and they lack context. Compared to sensory perceptions, mental simulations are mere cardboard cut-outs of reality. They are convincing enough to elicit brief hedonic reactions from subcortical systems, but because they differ from perceptions in such fundamental ways, the reactions they elicit may differ as well. Although prospection allows us to navigate time in a way that no other animal can, we still see more than we foresaw.

Evolving size of the social brain.

Dunbar and Shultz ask why primates have such large brains, compared to their body mass, compared with other animals. Here is their abstract, followed by a central clip from their article:

The evolution of unusually large brains in some groups of animals, notably primates, has long been a puzzle. Although early explanations tended to emphasize the brain's role in sensory or technical competence (foraging skills, innovations, and way-finding), the balance of evidence now clearly favors the suggestion that it was the computational demands of living in large, complex societies that selected for large brains. However, recent analyses suggest that it may have been the particular demands of the more intense forms of pairbonding that was the critical factor that triggered this evolutionary development. This may explain why primate sociality seems to be so different from that found in most other birds and mammals: Primate sociality is based on bonded relationships of a kind that are found only in pairbonds in other taxa.

Figure - In anthropoid primates, mean social group size increases with relative neocortex volume (indexed as the ratio of neocortex volume to the volume of the rest of the brain). Solid circles, monkeys; open circles, apes. Regression lines are reduced major axis fits.


The important issue in the present context is the marked contrast between anthropoid primates and all other mammalian and avian taxa (including, incidentally, prosimian primates): Only anthropoid primates exhibit a correlation between social group size and relative brain (or neocortex) size. This quantitative relationship is extremely robust; no matter how we analyze the data (with or without phylogenetic correction, using raw volumes, or residuals or ratios against any number of alternative body or brain baselines) or which brain data set we use (histological or magnetic resonance imaging derived, for whole brain, neocortex, or just the frontal lobes), the same quantitative relationship always emerges. This suggests that, at some early point in their evolutionary history, anthropoid primates used the kinds of cognitive skills used for pairbonded relationships by vertebrates to create relationships between individuals who are not reproductive partners. In other words, in primates, individuals of the same sex as well as members of the opposite sex could form just as intense and focused a relationship as do reproductive mates in nonprimates. Given that the number of possible relationships is limited only by the number of animals in the group, primates naturally exhibit a positive correlation between group size and brain size. This would explain why, as primatologists have argued for decades, the nature of primate sociality seems to be qualitatively different from that found in most other mammals and birds. The reason is that the everyday relationships of anthropoid primates involve a form of "bondedness" that is only found elsewhere in reproductive pairbonds.

MindBlog's home this morning...

The 1860 stone schoolhouse with its satellite dishes.

Nonhuman primates perceive human goals

Hauser and collaborators do a clever experiment to demonstrate that several primates can make inferences about a human experimenters goal that cannot be explained by simple associative learning. This means that our capacity to infer rational, goal-directed action derives from capabilities present in monkeys ~40 million years ago. Here is their abstract and a figure showing the basic idea of the experiment.

Humans are capable of making inferences about other individuals' intentions and goals by evaluating their actions in relation to the constraints imposed by the environment. This capacity enables humans to go beyond the surface appearance of behavior to draw inferences about an individual's mental states. Presently unclear is whether this capacity is uniquely human or is shared with other animals. We show that cotton-top tamarins, rhesus macaques, and chimpanzees all make spontaneous inferences about a human experimenter's goal by attending to the environmental constraints that guide rational action. These findings rule out simple associative accounts of action perception and show that our capacity to infer rational, goal-directed action likely arose at least as far back as the New World monkeys, some 40 million years ago.


Figure: During each trial, an experimenter presented subjects with two potential food containers, performed an action on one, and then allowed the subject to select one of the containers. In the intentional condition, the experimenter reached directly for and grasped the container. In the accidental condition, the experimenter flopped his hand onto the container with palm facing upwards in a manner that appeared, from a human perspective, accidental and non–goal-directed (13). If non-human primates fail to distinguish between intentional and accidental actions when making inferences about others' goals, attending to the mere association of the hand and container, then they should show the same pattern of searching in both conditions—that is, approach the experimenter-contacted container. However, if they distinguish between intentional and accidental actions, then they should selectively inspect the container targeted by the experimenter'sintentional action but not that targeted by accidental action.