Friday, February 27, 2009

Gesture and language acquisition

Gestures precede speech development and, after speech development, continue to enrich the communication process. Comparing how young children and their parents used gesture in their communications with analyses of socioeconomic status and of the child's vocabulary at age 54 months, Rowe and Goldin-Meadow find disparities in gesture use that precede vocabulary disparities (Children from lower socioeconomic brackets tend to have smaller vocabularies than children from higher socioeconomic brackets.) Their abstract:

Children from low–socioeconomic status (SES) families, on average, arrive at school with smaller vocabularies than children from high-SES families. In an effort to identify precursors to, and possible remedies for, this inequality, we videotaped 50 children from families with a range of different SES interacting with parents at 14 months and assessed their vocabulary skills at 54 months. We found that children from high-SES families frequently used gesture to communicate at 14 months, a relation that was explained by parent gesture use (with speech controlled). In turn, the fact that children from high-SES families have large vocabularies at 54 months was explained by children's gesture use at 14 months. Thus, differences in early gesture help to explain the disparities in vocabulary that children bring with them to school.

Followup on genes and language

I wanted to pass on some summary clips from a review by Berwick of the paper featured in a Feb. 12 post on an article by Chater et al. ("Language evolved to fit the human brain...").

Is language more like fashion hemlines or more like the number of fingers on each hand? On the one hand, we know that all normal people, unlike any cats or fish, uniformly grow up speaking some language, just like having 5 fingers on each hand, so language must be part of what is unique to the human genome. However, if one is born in Beijing one winds up speaking a very different language than if one is born in Mumbai, so the number-of-fingers analogy is not quite correct.
The Chater et al. article:
...maintains that the linguistic particulars distinguishing Mandarin from Hindi cannot have arisen as genetically encoded and selected-for adaptations via at least one common route linking evolution and learning, the Baldwin–Simpson effect

In the Baldwin–Simpson model, rather than direct selection for a trait, in this case a particular external behavior, there is selection for learning it. However, as is well known, this entrainment linking learning to genomic encoding works only if there is a close match between the pace of external change and genetic change, even though gene frequencies change only relatively slowly, plodding generation by generation. Applied to language evolution, the basic idea of Chater et al. is to use computer simulations to show that in general the linguistic regularities learners must acquire, such as whether sentences get packaged into verb–object order, e.g., eat apples, as in Mandarin, or object-verb order, e.g., apples eat, as in Hindi, can fluctuate too rapidly across generations to be captured and then encoded by the human genome as some kind of specialized “language instinct.” This finding runs counter to one popular view that these properties of human language were explicitly selected for, instead pointing to human language as largely adventitious, an exaptation, with many, perhaps most, details driven by culture. If this finding is correct, then the portion of the human genome devoted to language alone becomes correspondingly greatly reduced. There is no need, and more critically no informational space, for the genome to blueprint some intricate set of highly-modular, interrelated components for language, just as the genome does not spell out the precise neuron-to-neuron wiring of the developing brain.
Matters boil down to recursion, which I have mentioned in several previous posts.
Chater et al.'s report also points to a rare convergence between the results from 2 quite different fields and methodologies that have often been at odds: the simulation-based, culturally-oriented approach of the PNAS study and a recent, still controversial trend in one strand of modern theoretical linguistics. Both arrive at the same conclusion: a minimal human genome for language. The purely linguistic effort strips away all of the special properties of language, down to the bare-bones necessities distinguishing us from all other species, relegating such previously linguistic matters such as verb–object order vs. object–verb order to extralinguistic factors, such as a general nonhuman cognitive ability to process ordered sequences aligned like beads on a string. What remains? If this recent linguistic program is on the right track, there is in effect just one component left particular to human language, a special combinatorial competence: the ability to take individual items like 2 words, the and apple, and then “glue” them together, outputting a larger, structured whole, the apple, that itself can be manipulated as if it were a single object. This operation runs beyond mere concatenation, because the new object itself still has 2 parts, like water compounded from hydrogen and oxygen, along with the ability to participate in further chemical combinations. Thus this combinatorial operation can apply over and over again to its own output, recursively, yielding an infinity of ever more structurally complicated objects, ate the apple, John ate the apple, Mary knows John ate the apple, a property we immediately recognize as the hallmark of human language, an infinity of possible meaningful signs integrated with the human conceptual system, the algebraic closure of a recursive operator over our dictionary.

This open-ended quality is quite unlike the frozen 10- to 20-word vocalization repertoire that marks the maximum for any other animal species. If it is simply this combinatorial promiscuity that lies at the heart of human language, making “infinite use of finite means,” then Chater et al.'s claim that human language is an exaptation rather than a selected-for adaptation becomes not only much more likely but very nearly inescapable.

Thursday, February 26, 2009

Envy and Schadenfreude in the brain.

Takahasi et al. show that experiencing envy at another person's success activates pain-related neural circuitry, whereas experiencing schadenfreude--delight at someone else's misfortune--activates reward-related neural circuitry. A graphic from the perspectives article by Lieberman and Eisenberger:


The pain and pleasure systems. The pain network consists of the dorsal anterior cingulate cortex (dACC), insula (Ins), somatosensory cortex (SSC), thalamus (Thal), and periaqueductal gray (PAG). This network is implicated in physical and social pain processes. The reward or pleasure network consists of the ventral tegmental area (VTA), ventral striatum (VS), ventromedial prefrontal cortex (VMPFC), and the amygdala (Amyg). This network is implicated in physical and social rewards.

Fetal testosterone predicts male-typical play.

In a survey of several hundred births (112 male, 100 female), Auyeung et al. have found a significant relationship between fetal testosterone and sexually differentiated play behavior in both boys and girls.

Mammals, including humans, show sex differences in juvenile play behavior. In rodents and nonhuman primates, these behavioral sex differences result, in part, from sex differences in androgens during early development. Girls exposed to high levels of androgen prenatally, because of the genetic disorder congenital adrenal hyperplasia, show increased male-typical play, suggesting similar hormonal influences on human development, at least in females. Here, we report that fetal testosterone measured from amniotic fluid relates positively to male-typical scores on a standardized questionnaire measure of sex-typical play in both boys and girls. These results show, for the first time, a link between fetal testosterone and the development of sex-typical play in children from the general population, and are the first data linking high levels of prenatal testosterone to increased male-typical play behavior in boys.

Wednesday, February 25, 2009

Monoamine oxidase A gene predicts aggression following provocation

From McDermott et al. :

Monoamine oxidase A gene (MAOA) has earned the nickname “warrior gene” because it has been linked to aggression in observational and survey-based studies. However, no controlled experimental studies have tested whether the warrior gene actually drives behavioral manifestations of these tendencies. We report an experiment, synthesizing work in psychology and behavioral economics, which demonstrates that aggression occurs with greater intensity and frequency as provocation is experimentally manipulated upwards, especially among low activity MAOA (MAOA-L) subjects. In this study, subjects paid to punish those they believed had taken money from them by administering varying amounts of unpleasantly hot (spicy) sauce to their opponent. There is some evidence of a main effect for genotype and some evidence for a gene by environment interaction, such that MAOA is less associated with the occurrence of aggression in a low provocation condition, but significantly predicts such behavior in a high provocation situation. This new evidence for genetic influences on aggression and punishment behavior complicates characterizations of humans as “altruistic” punishers and supports theories of cooperation that propose mixed strategies in the population. It also suggests important implications for the role of individual variance in genetic factors contributing to everyday behaviors and decisions.

Musical training enhances linguistic abilities in children

An interesting report from Moreno et al. in the journal Cerebral Cortex. They:

...conducted a longitudinal study with 32 nonmusician children over 9 months to determine 1) whether functional differences between musician and nonmusician children reflect specific predispositions for music or result from musical training and 2) whether musical training improves nonmusical brain functions such as reading and linguistic pitch processing. Event-related brain potentials were recorded while 8-year-old children performed tasks designed to test the hypothesis that musical training improves pitch processing not only in music but also in speech. Following the first testing sessions nonmusician children were pseudorandomly assigned to music or to painting training for 6 months and were tested again after training using the same tests. After musical (but not painting) training, children showed enhanced reading and pitch discrimination abilities in speech. Remarkably, 6 months of musical training thus suffices to significantly improve behavior and to influence the development of neural processes as reflected in specific pattern of brain waves. These results reveal positive transfer from music to speech and highlight the influence of musical training. Finally, they demonstrate brain plasticity in showing that relatively short periods of training have strong consequences on the functional organization of the children's brain.

Tuesday, February 24, 2009

Training your working memory increases your cortical Dopamine D1 receptors

McNab et al demonstrate training-induced brain changes that indicate an unexpectedly high level of plasticity of our cortical dopamine D1 system and illustrate the mutual interdependence of our behavior and the underlying brain biochemistry. The training included a visuo-spatial working memory task, a backwards digit span task and a letter span task. These are similar to the n-back tests that I have mentioned in previous posts. The authors had previously shown increased prefrontal and parietal activity after training of working memory. Their abstract:

Working memory is a key function for human cognition, dependent on adequate dopamine neurotransmission. Here we show that the training of working memory, which improves working memory capacity, is associated with changes in the density of cortical dopamine D1 receptors. Fourteen hours of training over 5 weeks was associated with changes in both prefrontal and parietal D1 binding potential. This plasticity of the dopamine D1 receptor system demonstrates a reciprocal interplay between mental activity and brain biochemistry in vivo.
A clip from their methods description:
Participants performed working memory (WM) tasks with a difficulty level close to their individual capacity limit for about 35 min per day over a period of 5 weeks (8–10). Thirteen volunteers (healthy males 20 to 28 years old) performed the 5-week WM training. Five computer-based WM tests (three visuospatial and two verbal) were used to measure each participant's WM capacity before and after training, and they showed a significant improvement of overall WM capacity (paired t test, t = 11.1, P less than 0.001). The binding potential (BP) of D1 and D2 receptors was measured with positron emission tomography (PET) while the participants were resting, before and after training, using the radioligands [11C]SCH23390 and [11C]Raclopride, respectively.

Malthusian information famine

A view of our information future from Charles Seife:

...Vast amounts of digital memory will change the relationship that humans have with information....For the first time, we as a species have the ability to remember everything that ever happens to us. For millennia, we were starving for information to act as raw material for ideas. Now, we are about to have a surfeit.

Alas, there will be famine in the midst of all that plenty. There are some hundred million blogs, and the number is roughly doubling every year. The vast majority are unreadable. Several hundred billion e-mail messages are sent every day; most of it—current estimates run around 70%—is spam. There seems to be a Malthusian principle at work: information grows exponentially, but useful information grows only linearly. Noise will drown out signal. The moment that we, as a species, finally have the memory to store our every thought, etch our every experience into a digital medium, it will be hard to avoid slipping into a Borgesian nightmare where we are engulfed by our own mental refuse.

Monday, February 23, 2009

Some Chopin for a Monday morning.

This is Chopin's Nocture Op. 9 No. 1, which I recorded last May. I miss my Steinway B grand piano back in Wisconsin during my current snowbird period in Fort Lauderdale Florida. I will probably do a burst of pent-up recordings when I get back in April.

How we decide how big a reward is...

Furlong and Opfer do a nice set of experiments showing that we can be lured into making decisions by numbers that seem bigger than they really are. We apparently go with numerical values rather than real economic values. They asked volunteers to take part in the prisoner’s dilemma behavioral test, in which two partners are offered various rewards to either work together or defect. The idea is that in the long term, the participants earn the most money by cooperating. But in any given round of play, they make the most if they decide to turn against their partner while he stays loyal. (The reward is lowest when both partners defect.) When the reward for cooperation was increased to 300 cents from 3 cents, the researchers found, the level of cooperation went up. But when the reward went from 3 cents to $3, it did not. Here is their abstract:

Cooperation often fails to spread in proportion to its potential benefits. This phenomenon is captured by prisoner's dilemma games, in which cooperation rates appear to be determined by the distinctive structure of economic incentives (e.g., $3 for mutual cooperation vs. $5 for unilateral defection). Rather than comparing economic values of cooperating versus not ($3 vs. $5), we tested the hypothesis that players simply compare numeric values (3 vs. 5), such that subjective numbers (mental magnitudes) are logarithmically scaled. Supporting our hypothesis, increasing only numeric values of rewards (from $3 to 300¢) increased cooperation, whereas increasing economic values increased cooperation only when there were also numeric increases. Thus, changing rewards from 3¢ to 300¢ increased cooperation rates, but an economically identical change from 3¢ to $3 elicited no gains. Finally, logarithmically scaled reward values predicted 97% of variation in cooperation, whereas the face value of economic rewards predicted none. We conclude that representations of numeric value constrain how economic rewards affect cooperation.

Similar risk assessment in man and mouse.

In an open access article Balci et al. devise a simple and clever timing task which captures the essence of temporal decision making that confronts human and nonhuman animal subjects in everyday life, and show that men are no better than mice in assessing a simple kind of uncertainty. This suggests that mechanisms for near-optimal risk assessment in many everyday contexts evolved long ago. Their abstract:

Human and mouse subjects tried to anticipate at which of 2 locations a reward would appear. On a randomly scheduled fraction of the trials, it appeared with a short latency at one location; on the complementary fraction, it appeared after a longer latency at the other location. Subjects of both species accurately assessed the exogenous uncertainty (the probability of a short versus a long trial) and the endogenous uncertainty (from the scalar variability in their estimates of an elapsed duration) to compute the optimal target latency for a switch from the short- to the long-latency location. The optimal latency was arrived at so rapidly that there was no reliably discernible improvement over trials. Under these nonverbal conditions, humans and mice accurately assess risks and behave nearly optimally. That this capacity is well-developed in the mouse opens up the possibility of a genetic approach to the neurobiological mechanisms underlying risk assessment.

Friday, February 20, 2009

How cute is that baby's face - hormones regulate the answer.

Sprengelmeyer et al. make some interesting observations suggesting that female reproductive hormones increase sensitivity to variations in the cuteness of baby faces. Their abstract:

We used computer image manipulation to develop a test of perception of subtle gradations in cuteness between infant faces. We found that young women (19–26 years old) were more sensitive to differences in infant cuteness than were men (19–26 and 53–60 years old). Women aged 45 to 51 years performed at the level of the young women, whereas cuteness sensitivity in women aged 53 to 60 years was not different from that of men (19–26 and 53–60 years old). Because average age at menopause is 51 years in Britain, these findings suggest the possible involvement of reproductive hormones in cuteness sensitivity. Therefore, we compared cuteness discrimination in pre- and postmenopausal women matched for age and in women taking and not taking oral contraceptives (progestogen and estrogen). Premenopausal women and young women taking oral contraceptives (which raise hormone levels artificially) were more sensitive to variations of cuteness than their respective comparison groups. We suggest that cuteness sensitivity is modulated by female reproductive hormones.

Modulation of the brain's emotion circuits by facial muscle feedback

Several studies have shown that facial muscle contractions associated with various emotions can induce or enhance the correlated emotional feelings, or counter them if the facial movements and central feelings are in opposition (as in forcing a smile while angry.) The late senator Proxmire of Wisconsin wrote a self help book that included instruction for making a 'happy face' to improve your mood. Hennenlotter et al. now do an interesting bit of work in which they observe that blocking the feedback of frown muscles to the brain lowers the level of amygdala activation during a subject's imitiation of an angry facial expression:

Afferent feedback from muscles and skin has been suggested to influence our emotions during the control of facial expressions. Recent imaging studies have shown that imitation of facial expressions is associated with activation in limbic regions such as the amygdala. Yet, the physiological interaction between this limbic activation and facial feedback remains unclear. To study if facial feedback effects on limbic brain responses during intentional imitation of facial expressions, we applied botulinum toxin (BTX)–induced denervation of frown muscles in combination with functional magnetic resonance imaging as a reversible lesion model to minimize the occurrence of afferent muscular and cutaneous input. We show that, during imitation of angry facial expressions, reduced feedback due to BTX treatment attenuates activation of the left amygdala and its functional coupling with brain stem regions implicated in autonomic manifestations of emotional states. These findings demonstrate that facial feedback modulates neural activity within central circuitries of emotion during intentional imitation of facial expressions. Given that people tend to mimic the emotional expressions of others, this could provide a potential physiological basis for the social transfer of emotion.

Thursday, February 19, 2009

The smell of fear modulates our perception of threat in faces

This is kind of neat: Zhou and Chen collected gauze pads that had absorbed sweat from the armpit apocrine glands of men (because they sweat more) watching a horror movie or a happy or neutral movie. Women sniffed the extracted smells (versus neutral controls) while watching a face morph from happy to frightened (women have more sensitive sense of smell and sensitivity to emotional signals). The chemosignal of fearful sweat biased the women toward interpreting ambiguous expressions as more fearful, but had no effect when the facial emotion was more discernible. This shows that fear-related chemosignals modulate humans' visual emotion perception in an emotion-specific way

Men tolerate their peers better than women

This study by Benenson et al. was conducted to examine the often-cited conclusion that human females are more sociable than males. Its results certainly correlate with my own university experience. In studying students at a Northeastern university they concluded that:

Males were more likely than females to be satisfied with their roommates and were less bothered by their roommates' style of social interaction, types of interests, values, and hygiene, regardless of whether or not the roommates were selected for study because they were experiencing conflicts. Furthermore, males were less likely than females to switch roommates over the course of a year at three collegiate institutions. Finally, violation of a friendship norm produced a smaller negative effect on friendship belief in males than in females.
They authors maintain (this surprises me, if true) that their studies are the first to demonstrate that males, compared with females, display higher levels of tolerance for genetically unrelated same-sex individuals.

Wednesday, February 18, 2009

When losing control can be useful.

Apfelbaum and Sommers do a simple experiment that suggests that diminished executive control can facilitate positive outcomes in contentious intergroup interactions. Here is their abstract, followed by a description of how the subject's sense of executive control was manipulated:

Across numerous domains, research has consistently linked decreased capacity for executive control to negative outcomes. Under some conditions, however, this deficit may translate into gains: When individuals' regulatory strategies are maladaptive, depletion of the resource fueling such strategies may facilitate positive outcomes, both intra- and interpersonally. We tested this prediction in the context of contentious intergroup interaction, a domain characterized by regulatory practices of questionable utility. White participants discussed approaches to campus diversity with a White or Black partner immediately after performing a depleting or control computer task. In intergroup encounters, depleted participants enjoyed the interaction more, exhibited less inhibited behavior, and seemed less prejudiced to Black observers than did control participants—converging evidence of beneficial effects. Although executive capacity typically sustains optimal functioning, these results indicate that, in some cases, it also can obstruct positive outcomes, not to mention the potential for open dialogue regarding divisive social issues.
Now, the following dinking with executive control to generate 'depleted' participants sort of makes sense to me, but I'm not sure I really get it...
The Attention Network Test is a computer-based measure of attention. We modified the ANT component typically used to gauge executive control into a manipulation of executive capacity. Across multiple trials, participants were presented with a string of five arrows and instructed to quickly and accurately indicate the direction of the center arrow (i.e., whether the arrow was pointing left or right). The center arrow was either congruent (i.e., ←←←←←, →→→→→) or incongruent (i.e., →→←→→, ←←→←←) with its flankers; correct responses to incongruent trials thus required executive control to override the natural tendency to follow the flankers. Participants in the depletion condition were presented with congruent and incongruent stimuli, whereas participants in the control condition viewed congruent stimuli only.

If it is difficult to pronounce, it must be risky.

Song and Schwartz make the observation that low processing fluency (as with names that are difficult to pronounce) fosters the impression that a stimulus is unfamiliar, which in turn results in perceptions of higher risk. Ostensible food additives were rated as more harmful when their names were difficult to pronounce than when their names were easy to pronounce, and amusement-park rides were rated as more likely to make one sick (an undesirable risk) and also as more exciting and adventurous (a desirable risk) when their names were difficult to pronounce than when their names were easy to pronounce.

Tuesday, February 17, 2009

Brain imaging can reflect expected, rather than actual, nerve activity

Work by Sirotin and Das illustrates how the brain thinks ahead. Electrical signalling among brain cells summons the local delivery of extra blood — the basis of functional brain imaging. And the usual assumption is that an increase in blood flow means an increase in electrical activity. The experiments by Sirotin and Das show that blood can be sent to the brain's visual cortex in the absence of any stimulus, priming the neural tissue in apparent anticipation of future events. (They observed this mismatch in alert rhesus monkeys by simultaneously measuring vascular and neural responses in the same region of the visual cortex. Changes in the blood supply were monitored by a sensitive video camera peering at the surface of the brain through a transparent window in the animal's skull, and local electrical responses of neurons were measured with a microelectrode.) Their results show that cortical blood flow can depart wildly from what is expected on the basis of local neural activity. Blood can be sent in anticipation of neural events that never take place.

Knowledge about how we know changes everything.

The essay by Boroditsky in the Edge series has the following interesting comments:

In the past ten years, research in cognitive science has started uncovering the neural and psychological substrates of abstract thought, tracing the acquisition and consolidation of information from motor movements to abstract notions like mathematics and time. These studies have discovered that human cognition, even in its most abstract and sophisticated form, is deeply embodied, deeply dependent on the processes and representations underlying perception and motor action. We invent all kinds of complex abstract ideas, but we have to do it with old hardware: machinery that evolved for moving around, eating, and mating, not for playing chess, composing symphonies, inventing particle colliders, or engaging in epistemology for that matter. Being able to re-use this old machinery for new purposes has allowed us to build tremendously rich knowledge repertoires. But it also means that the evolutionary adaptations made for basic perception and motor action have inadvertently shaped and constrained even our most sophisticated mental efforts. Understanding how our evolved machinery both helps and constrains us in creating knowledge, will allow us to create new knowledge, either by using our old mental machinery in yet new ways, or by using new and different machinery for knowledge-making, augmenting our normal cognition.

So why will knowing more about how we know change everything? Because everything in our world is based on knowledge. Humans, leaps and bounds beyond any other creatures, acquire, create, share, and pass on vast quantities of knowledge. All scientific advances, inventions, and discoveries are acts of knowledge creation. We owe civilization, culture, science, art, and technology all to our ability to acquire and create knowledge. When we study the mechanics of knowledge building, we are approaching an understanding of what it means to be human—the very nature of the human essence. Understanding the building blocks and the limitations of the normal human knowledge building mechanisms will allow us to get beyond them. And what lies beyond is, well, yet unknown...

Monday, February 16, 2009

Robocop and cello scrotum

I thought these two items in the Random Samples section of the Feb. 6 Science Magazine were a hoot:

FIDDLE WITHOUT FEAR:

Elaine Murphy was just starting her medical career in 1974 when she and her husband, John, pulled a fast one on the editors of the British Medical Journal (BMJ). The joke's long run ended last week when the Murphys confessed that a medical condition, "cello scrotum," they coined in a letter to the journal 35 years ago doesn't exist.

Now a baroness and member of the British House of Lords, Murphy and her partner in crime admitted the hoax in a letter published 27 January in BMJ. The couple came up with the prank after reading a letter to BMJ in April 1974 on "guitar nipple," an alleged chest inflammation that the couple assumed was fake. In the spirit of one-upmanship, the pair wrote a short note on "cello scrotum," an inflammation on a fabricated patient who played the cello for hours each day. "We never expected our spoof letter to be published," Murphy says. "We probably wrote it after a glass of wine or two."

The Murphys came clean after finding a reference to cello scrotum in a December 2008 issue of the journal. Although journal editors disapprove of dishonesty in science, Tony Delamothe, a deputy editor at BMJ, says that the Murphys' joke was harmless. "All of my colleagues, from the editor down, think it's a hoot," Delamothe says. Murphy adds that she's received no negative fallout. "I was worried the House of Lords would think I was bringing them into disrepute," she says, "but so far, everyone wants to enjoy the joke."

NEW SHERIFF IN TOWN:

It's not RoboCop, but Japanese robotmaker Tmsuk believes its T-34 security robot can fight crime by snaring intruders in an entangling net. The 60-centimeter-tall robot sends real-time video of its surroundings to a remote operator's mobile phone over Japan's advanced mobile phone service, eliminating the need for cables or wireless networks. On command, the T-34 fires a weighted net capable of enveloping a human target up to 3.5 meters away, holding the suspected criminal until security officers arrive. Tmsuk, which worked with security service provider Alacom in developing the T-34, says the robot could confront dangerous intruders while keeping human guards at a safe distance. "We think this could serve the needs of the security industry," says company spokesperson Mariko Ishikawa. The company recently demonstrated a working prototype and says a commercial model could be on the market in a few years for about $5000.

Brain correlates of dealing with risk versus ambiguity

Because it is relevant to last friday's post on the economic situation, I thought I would bring forward this bit of work which I had been planning to mention soon. It is yet another interesting study from the group at Wellcome Center group at University College associated with Ray Dolan - cognitive neuroscience that is directly relevant to our current economic and political reality:

In economic decision making, outcomes are described in terms of risk (uncertain outcomes with certain probabilities) and ambiguity (uncertain outcomes with uncertain probabilities). Humans are more averse to ambiguity than to risk, with a distinct neural system suggested as mediating this effect. However, there has been no clear disambiguation of activity related to decisions themselves from perceptual processing of ambiguity. In a functional magnetic resonance imaging (fMRI) experiment, we contrasted ambiguity, defined as a lack of information about outcome probabilities, to risk, where outcome probabilities are known, or ignorance, where outcomes are completely unknown and unknowable. We modified previously learned pavlovian CS+ stimuli such that they became an ambiguous cue and contrasted evoked brain activity both with an unmodified predictive CS+ (risky cue), and a cue that conveyed no information about outcome probabilities (ignorance cue). Compared with risk, ambiguous cues elicited activity in posterior inferior frontal gyrus and posterior parietal cortex during outcome anticipation. Furthermore, a similar set of regions was activated when ambiguous cues were compared with ignorance cues. Thus, regions previously shown to be engaged by decisions about ambiguous rewarding outcomes are also engaged by ambiguous outcome prediction in the context of aversive outcomes. Moreover, activation in these regions was seen even when no actual decision is made. Our findings suggest that these regions subserve a general function of contextual analysis when search for hidden information during outcome anticipation is both necessary and meaningful.
The authors also comment on previous work emphasizing the amygdala:
In contrast to the present experiment, a previous fMRI study has suggested that the amygdala and dorsomedial prefrontal and orbitofrontal cortex underlie decision making under ambiguity (Hsu et al., 2005). ... Although it is obvious that the amygdala responds to some kinds of uncertainty [e.g., temporal unpredictability], different forms of uncertainty have not been formally compared with regard to such responses. The kind of outcome uncertainty described in the aforementioned work is likely to be different from the economic definition applied in the present study (e.g., the lack of knowledge about CS–UCS contingencies in fear conditioning paradigms corresponds to the ignorance and not the ambiguity condition in the present study). The study by Hsu et al. (2005), although concerned with an economic definition of ambiguity, in fact collapsed different kinds of "ambiguous" situations for analysis of fMRI data, that is, monetary gambles following a strict economic definition, but also quizzes, and uninformed gambles against an informed opponent. Together, the data indicate that there is no entirely convincing empirical evidence that the amygdala responds to ambiguity as defined in a strict economic sense, an inference upheld by our present findings, although such a role of the amygdala cannot be discounted entirely (Seymour and Dolan, 2008).

Placebos, curing within...

I wanted to pass on two pieces on self curing and the placebo effect pointed out to me by a mindblog reader. Amanda Schaffer offers a review in Slate on Anne Harrington's new book "The Cure Within", which maps the history of mind-body medicine. Also, a recent study testing pain relief from analgesics shows that merely telling people that a novel form of codeine they were taking (actually a placebo) was worth $2.50 rather than 10 cents increased the proportion of people who reported pain relief from 61% to 85.4%.1 When the "price" of the placebo was reduced, so was the pain relief.

Friday, February 13, 2009

Run for the hills.....

Three items in today's New York Times are sufficienly pungent to warrant mention. Lohr's article gives a clear exposition of the fact that the nation's banking system is effectively insolvent, it's debts being greater than its assets. Krugman again notes the futility of current plans which avoid shutting down the bad banks (and wiping out their investors) and saving the solvent ones. And Brooks, in an OpEd piece that motivated me to go ahead with this post, paints a pessimistic imagined future scenario for 2010 influenced by his reading of current cognitive neuroscience (Here, for example, is a relevant article, more recent than the work that Brooks was aware of, showing structures that appear to be more important than the amygdala in dealing with uncertainty). From Brooks' piece:

The problem was this: The policy makers knew how to pull economic levers, but they did not know how to use those levers to affect social psychology.

The crisis was labeled an economic crisis, but it was really a psychological crisis. It was caused by a mood of fear and uncertainty, which led consumers to not spend, bankers to not lend and entrepreneurs to not risk. No amount of federal spending could change this psychology because uncertainty about the future remained acute.

Essentially, Americans had migrated from one society to another — from a society of high trust to a society of low trust, from a society of optimism to a society of foreboding, from a society in which certain financial habits applied to a society in which they did not. In the new world, investors had no basis from which to calculate risk. Families slowly deleveraged. Bankers had no way to measure the future value of assets.

Cognitive scientists distinguish between normal risk-assessment decisions, which activate the reward-prediction regions of the brain, and decisions made amid extreme uncertainty, which generate activity in the amygdala. These are different mental processes using different strategies and producing different results. Americans were suddenly forced to cope with this second category, extreme uncertainty.

Economists and policy makers had no way to peer into this darkness. Their methods were largely based on the assumption that people are rational, predictable and pretty much the same. Their models work best in times of equilibrium. But in this moment of disequilibrium, behavior was nonlinear, unpredictable, emergent and stubbornly resistant to Keynesian rationalism.

...The nation had essentially bet its future on economic models with primitive views of human behavior. The government had tried to change social psychology using the equivalent of leeches and bleeding.

(A friend of mine claims to know a former hedge fund manager who has converted his assets to gold coins, and bought a safe, and a shotgun!)

Faster evolution means more ethnic differences.

Some interesting thoughts from Jonathan Haidt:

...a betting person would have to predict that as we decode the genomes of people around the world, we're going to find deeper differences than most scientists now expect...A wall has long protected respectable evolutionary inquiry from accusations of aiding and abetting racism. That wall is the belief that genetic change happens at such a glacial pace that there simply was not time, in the 50,000 years since humans spread out from Africa, for selection pressures to have altered the genome in anything but the most trivial way (e.g., changes in skin color and nose shape were adaptive responses to cold climates). ...But the writing is on the wall. Russian scientists showed in the 1990s that a strong selection pressure (picking out and breeding only the tamest fox pups in each generation) created what was — in behavior as well as body — essentially a new species in just 30 generations. That would correspond to about 750 years for humans.

Humans may never have experienced such a strong selection pressure for such a long period, but they surely experienced many weaker selection pressures that lasted far longer, and for which some heritable personality traits were more adaptive than others. It stands to reason that local populations (not continent-wide "races") adapted to local circumstances by a process known as "co-evolution" in which genes and cultural elements change over time and mutually influence each other. The best documented example of this process is the co-evolution of genetic mutations that maintain the ability to fully digest lactose in adulthood with the cultural innovation of keeping cattle and drinking their milk. This process has happened several times in the last 10,000 years, not to whole "races" but to tribes or larger groups that domesticated cattle.

...traits that led to Darwinian success in one of the many new niches and occupations of Holocene life — traits such as collectivism, clannishness, aggressiveness, docility, or the ability to delay gratification — are often seen as virtues or vices. Virtues are acquired slowly, by practice within a cultural context, but the discovery that there might be ethnically-linked genetic variations in the ease with which people can acquire specific virtues is — and this is my prediction — going to be a "game changing" scientific event. (By "ethnic" I mean any group of people who believe they share common descent, actually do share common descent, and that descent involved at least 500 years of a sustained selection pressure, such as sheep herding, rice farming, exposure to malaria, or a caste-based social order, which favored some heritable behavioral predispositions and not others.)

I believe that the "Bell Curve" wars of the 1990s, over race differences in intelligence, will seem genteel and short-lived compared to the coming arguments over ethnic differences in moralized traits. I predict that this "war" will break out between 2012 and 2017...There are reasons to hope that we'll ultimately reach a consensus that does not aid and abet racism. I expect that dozens or hundreds of ethnic differences will be found, so that any group — like any person — can be said to have many strengths and a few weaknesses, all of which are context-dependent. Furthermore, these cross-group differences are likely to be small when compared to the enormous variation within ethnic groups and the enormous and obvious effects of cultural learning. But whatever consensus we ultimately reach, the ways in which we now think about genes, groups, evolution and ethnicity will be radically changed by the unstoppable progress of the human genome project.

Caloric restriction improves memory

From Witte et al:

Animal studies suggest that diets low in calories and rich in unsaturated fatty acids (UFA) are beneficial for cognitive function in age. Here, we tested in a prospective interventional design whether the same effects can be induced in humans. Fifty healthy, normal- to overweight elderly subjects (29 females, mean age 60.5 years, mean body mass index 28 kg/m2) were stratified into 3 groups: (i) caloric restriction (30% reduction), (ii) relative increased intake of UFAs (20% increase, unchanged total fat), and (iii) control. Before and after 3 months of intervention, memory performance was assessed under standardized conditions. We found a significant increase in verbal memory scores after caloric restriction (mean increase 20%; P less than 0.001), which was correlated with decreases in fasting plasma levels of insulin and high sensitive C-reactive protein, most pronounced in subjects with best adherence to the diet (all r values less than −0.8; all P values less than 0.05). Levels of brain-derived neurotrophic factor remained unchanged. No significant memory changes were observed in the other 2 groups. This interventional trial demonstrates beneficial effects of caloric restriction on memory performance in healthy elderly subjects. Mechanisms underlying this improvement might include higher synaptic plasticity and stimulation of neurofacilitatory pathways in the brain because of improved insulin sensitivity and reduced inflammatory activity. Our study may help to generate novel prevention strategies to maintain cognitive functions into old age.

Thursday, February 12, 2009

Pavlovian conditioning can transfer from the virtual world to the real world

McCabe et al. offer an intriguing experiment showing that conditioning-dependent motivational properties can transfer from a computer game to the real world and also be expressed in terms of brain responses measured using functional magnetic resonance imaging (fMRI). They studied healthy participants conditioned with aversive and appetitive drinks in the context of a virtual cycling race. Three days after conditioning, participants returned for a fMRI session. They used this opportunity to observe the impact of incidental presentation of conditioned stimuli on a real-world decision (seat choice, see the figures below). They found a significant influence of conditioning on seat choice and, moreover, noted that individual susceptibility to this influence was reflected in differential insula cortex responses during subsequent scanning. Thus a stimulus in a virtual environment can acquire motivational properties that persist and modify behavior in the real world.



Figure - Day 1: Pavlovian conditioning in virtual environment. Participants in the virtual cycle race were overtaken by competitors. The stimuli on the competitors' jerseys acted as CSs predicting the delivery of either pleasant or unpleasant juice. The stimulus-to-juice assignment was counterbalanced across participants.


Figure - Day 4: Real-world decision when asked to take a seat in an unoccupied waiting room before scanning. Sixteen participants chose the seat bearing a towel with the CS+app.

Language evolved to fit the human brain, rather than the reverse.

I thought this PNAS article from Chater et al. on language evolution was interesting. Here are a few excerpts from their introduction, followed by their abstract (and here is a commentary in a following issue of PNAS):

...the default prediction from a Darwinian perspective on human psychological abilities is the adaptationist view, that genes for language coevolved with human language itself for the purpose of communication...A challenge for the adaptationists is to pinpoint an evolutionary mechanism by which a language module could become genetically encoded. The problem is that many of the linguistic properties purported to be included in the language module are highly abstract and have no obvious functional basis—they cannot be explained in terms of communicative effectiveness or cognitive constraints—and have even been suggested to hinder communication...

A shift from initially learned linguistic conventions to genetically encoded principles necessary to evolve a language module may appear to require Lamarckian inheritance. The Baldwin effect provides a possible Darwinian solution to this challenge, however. Baldwin proposed that characteristics that are initially learned or developed over the lifespan can become gradually encoded in the genome over many generations, because organisms with a stronger predisposition to acquire a trait have a selective advantage. Over generations, the amount of environmental exposure required to develop the trait decreases, and eventually no environmental exposure may be needed—the trait is genetically encoded.
Chater et al. modeled several different simulations of the circumstances under which a similar evolutionary mechanism could genetically assimilate properties of language in a domain-specific module. Here is their abstract:
Language acquisition and processing are governed by genetic constraints. A crucial unresolved question is how far these genetic constraints have coevolved with language, perhaps resulting in a highly specialized and species-specific language “module,” and how much language acquisition and processing redeploy preexisting cognitive machinery. In the present work, we explored the circumstances under which genes encoding language-specific properties could have coevolved with language itself. We present a theoretical model, implemented in computer simulations, of key aspects of the interaction of genes and language. Our results show that genes for language could have coevolved only with highly stable aspects of the linguistic environment; a rapidly changing linguistic environment does not provide a stable target for natural selection. Thus, a biological endowment could not coevolve with properties of language that began as learned cultural conventions, because cultural conventions change much more rapidly than genes. We argue that this rules out the possibility that arbitrary properties of language, including abstract syntactic principles governing phrase structure, case marking, and agreement, have been built into a “language module” by natural selection. The genetic basis of human language acquisition and processing did not coevolve with language, but primarily predates the emergence of language. As suggested by Darwin, the fit between language and its underlying mechanisms arose because language has evolved to fit the human brain, rather than the reverse.

Happy 200th birthday to Charles Darwin!

Wednesday, February 11, 2009

MindBlog's third Podcast - Mindstuff: A user's guide

This podcast (here is the mp3, 30 min., 13.8 MB download) builds on the description of the nature and evolutionary history of our "I" that is developed in the first two Podcasts, "The I-Illusion" and "The Beast Within." In this podcast, which I am calling Mindstuff: A user's guide, I address a not-so-hidden agenda for many of us trying to understand our minds and brains: wanting to find insights or tools that bring more ease to the living of our daily lives, tools that might also enhance our effectiveness in tasks we wish to accomplish. I am adding some material to, and abstracting from, writing on my website, dericbownds.net. This is as close as I will get to offering my own version of a self-help manual that is based on our limited knowledge of how our minds actually work.

Worldwide human energy networking

In the last article of the Nature Magazine "Being Human" series, Melanie Moses discusses humanity's greatest challenge: how to reduce the demand for energy in increasingly complex, networked and energy-dependent societies. A few excerpts:

To manage our impact on the environment and understand the ramifications of our actions in an increasingly interconnected world, we need a macroscopic view as well as a detailed understanding of the structure of the networks we have created. The bigger picture is beginning to emerge from theoretical approaches that reveal the structure and dynamics of networks, how networks change as they grow, and how networks constrain individual behaviour.

The Metabolic Theory of Ecology (MTE) offers one way to understand the dynamics of flow through networks. The mathematical foundation of MTE was developed a decade ago by a group of biologists and physicists who wanted to explain why so many characteristics of plants and animals systematically depend on their mass in a very peculiar way. The theory posits that much of the life history of an animal (such as how long it lives, how often it reproduces and how much it eats) is determined by geometric and dynamic properties of the cardiovascular network that controls its metabolism.

According to the theory, the larger the animal, the longer its cardiovascular system (its network of arteries and capillaries) takes to deliver resources to its cells. That delivery time, which in turn dictates the animal's metabolic rate, is proportional to the animal's mass raised to the power of ¼. Thus, because its circulatory system works less efficiently, an elephant grows systematically more slowly than a mouse, with a slower heart rate, a lower reproductive rate and a longer lifespan

... the implications of this basic idea — that networks become predictably less efficient as they grow — are profound. Indeed, MTE offers insights that could revolutionize the way we understand, predict and manage large networked systems. As well as suggesting that larger systems process energy proportionally more slowly than smaller ones, it implies that the rate at which a system processes energy drives much of its broad-scale behaviour, whether that system is an organism, society or technology.

Several crucial messages are emerging from early work on human-engineered networks. Human societies are complex systems that persist by consuming energy, but energy consumption cannot be lessened simply by reducing individual demand. Any one person's consumption and, possibly, fertility rate, is affected by structures at higher levels. Relating the behaviour of individuals to global-scale problems will require understanding those individuals as nodes in a network, in which the behaviour of one affects the whole society and where the collective behaviour of the society constrains the behaviour of individuals.

...potentially more efficient ways to design infrastructure are emerging. My colleagues and I recently showed that some at least partially decentralized networks, such as computer networks and urban roads in cities (where half the world's population now resides), can increase in size more efficiently than purely centralized ones. For example, our models show that traffic, and so oil consumption, can be proportionally reduced as cities expand, as long as multiple recreational and commercial centres are placed near residential areas. Moreover, Luís Bettencourt and his colleagues recently showed that certain factors, such as innovation and wealth creation, increase super-linearly with city population. In this instance, the more people in a city, the more each person benefits from the collective ability to interact.

...we need to understand how social and infrastructure networks constrain individual behaviour, and structure cities and societies in ways that increase innovation-inducing interactions but reduce transport and travel distances. By doing so, we'll stand a better chance of meeting the needs of a large, voracious and growing human population without decimating the resources available to future generations.

Fingerprints enhance the sense of touch.

Here is a curious factoid, or near factoid. From Miller's review of Scheibert et al.:

After a series of experiments with a sensor designed to mimic a small patch of skin on a human fingertip, Alexis Prevost, Georges Debrégeas, and their colleagues at the École Normale Supérieure in Paris conclude that fingerprints likely enhance the perception of texture by increasing vibrations in the skin as fingers rub across a textured surface. In particular, fingerprints amplify vibrations in the frequency range that best stimulates Pacinian corpuscles, mechanoreceptors in the skin important for texture perception...The ridges made the vibrations picked up by the underlying sensor up to 100 times stronger...The new results leave open why human fingerprints are arranged in elliptical swirls....the amplification effect was strongest when the textured glass slid perpendicular to the ridges, so it's possible that the loops ensure that no matter how the fingers move, some ridges are always optimally oriented.

Tuesday, February 10, 2009

God needn't actually exist to have evolved

Here are some clips from a brief essay by Jesse Bering, who is director of The Institute of Cognition and Culture, Queens University, Belfast.

What if I were to tell you that God were all in your mind? That God, like a tiny spec floating at the edge of your cornea producing the image of a hazy, out-of-reach orb accompanying your every turn, were in fact an illusion, a psychological blemish etched onto the core cognitive substrate of your brain?...Consider, briefly, the implications of seeing God this way, as a sort of scratch on our psychological lenses rather than the enigmatic figure out there in the heavenly world most people believe him to be. Subjectively, God would still be present in our lives. In fact rather annoyingly so. As a way of perceiving, he would continue to suffuse our experiences with an elusive meaning and give the sense that the universe is communicating with us in various ways.

...in the natural sciences, the concept of God as a causal force tends to be an unpalatable lump of gristle. Although treating God as an illusion may not be entirely philosophically warranted, therefore, it is in fact a scientifically valid treatment. Because the human brain, like any physical organ, is a product of evolution, and since natural selection works without recourse to intelligent forethought, this mental apparatus of ours evolved to think about God quite without need of the latter's consultation, let alone his being real.

...the human brain has many such odd quips that systematically alter, obscure, or misrepresent entirely the world outside our heads. That's not a bad thing necessarily; nor does it imply poor adaptive design. You have undoubtedly seen your share of optical illusions before, such as the famous Müller-Lyer image where a set of arrows of equal length with their tails in opposite directions creates the subjective impression that one line is actually longer than the other. You know, factually, the lines are of equal length, yet despite this knowledge your mind does not allow you to perceive the image this way. There are also well-documented social cognitive illusions that you may not be so familiar with. For example, David Bjorklund, a developmental psychologist, reasons that young children's overconfidence in their own abilities keeps them engaging in challenging tasks rather than simply giving up when they fail. Ultimately, with practice and over time, children's actual skills can ironically begin to more closely approximate these earlier, favorably warped self-judgments. Similarly, evolutionary psychologists David Buss and Martie Haselton argue that men's tendency to over-interpret women's smiles as sexual overtures prompts them to pursue courtship tactics more often, sometimes leading to real reproductive opportunities with friendly women.

...from both a well-being and a biological perspective, whether our beliefs about the world 'out there' are true and accurate matters little. Rather, psychologically speaking, it's whether they work for us—or for our genes—that counts. As you read this, cognitive scientists are inching their way towards a more complete understanding of the human mind as a reality-bending prism. What will change everything? The looming consensus among those who take Occam's Razor seriously that the existence of God is a question for psychologists and not physicists.

For memory enhancement, the kind of sleep you get is important

Van Der Werf et al. have recorded electroencephalograms from people as they slept, setting off a beeping sound when the electroencephalograms were consistent with slow-wave (deeper) sleep, thus causing subjects to move into a shallower sleep stage without awakening. Although the total amount of sleep that subjects got was unchanged, these people did worse on a later test of scene recall than subjects who had slept normally. When the subjects were later scanned in a functional magnetic resonance imaging scanner, they also showed reduced hippocampal activation while they were encoding the to-be-remembered scenes. Thus the hippocampus appears to be particularly sensitive to shallow, but intact, sleep.

Monday, February 09, 2009

The unconscious psychology of color.

When I first started the vision research laboratory I ran for 30 years at the University of Wisconsin, I experimented with the color spectrum of the fluorescent lights used over the laboratory benches. Those that had more blue and green, more like natural sunlight, clearly made my students feel more relaxed and creative. This was consonant with psychological studies that had shown reds to have more arousing and blue more calming effects humans as well as other animals. Mehta and Zhu have made some fascinating further observations reported in Science and noted in a NY Times article by Belluck which gives examples of similar studies. Work done against the background color red is relatively more accurate, while with blue it is more creative. Here is a clip from the Mehta and Zhu abstract, followed by a graphic from the NY Times article.

We demonstrate that red (versus blue) color induces primarily an avoidance (versus approach) motivation and that red enhances performance on a detail-oriented task, whereas blue enhances performance on a creative task. Further, we replicate these results in domains of product design and persuasive message evaluation, and illustrate that these effects occur outside of individuals’ consciousness . We also provide process evidence suggesting that the activation of alternative motivations mediates the effect of color on cognitive task performances.




Supersizing the Mind

Supersizing the Mind: Embodiment, Action, and Cognitive Extension, a recent book by philosopher Andy Clark is reviewed by Melvyn Goodale in Nature, and I pass on some clips from his review, because Clark's views exactly mirror the sentiments expressed in my Biology of Mind Book:

In Supersizing the Mind, philosopher Andy Clark makes the compelling argument that the mind extends beyond the body to include the tools, symbols and other artefacts we deploy to engage the world. According to Clark and other proponents of the 'extended mind' hypothesis, the laptop on which I am writing this review is coupled to my brain and has become part of my mind. Manipulating sentences on the screen can prompt new insights and new ways of conveying ideas, a reiterative cognitive process that would be difficult to achieve without such a tool. The same argument applies to my BlackBerry, to the white board in my office, and even to the conversations I might have with my colleagues. Cognition, Clark argues, is not 'brain-bound' but a dynamic interaction between the neural circuits inside our skulls, our bodies and the objects and events in the outside world.

Clark explores in detail the consequences of embodied and extended cognition for our conscious perception of the world. He acknowledges that the "intimacy of brain, body, world, and action" must have implications for our perceptual experience, but ultimately rejects the idea of enactive perception championed by philosopher Alva Noë, in which our experience is seen as nothing more than the sensorimotor routines that we use to interact with the world. For Clark, perception is shaped by the way in which we explore this world. But at the same time, he argues, our conscious experience of objects and events is not bound to the details of the sensorimotor routines that mediate that exploration. These routines, he suggests, are controlled by encapsulated systems with operating characteristics that are not privy to conscious, or even unconscious, scrutiny and whose activity is removed from the information they convey. In rejecting Noë's sensorimotor model, Clark argues that conscious perception does not depend on a "common sensorimotor currency" but arises from a subtle interplay between brain, body and environment, "replete with special-purpose streaming and with multiple, quasi-independent forms of internal, and external, representation and processing".

If Clark is right, and I think he is, then simply studying what goes on in the brain will tell us only part of what happens as cognitive activity unfolds. To capture the richness of thought, we have to step outside the box and embrace the world beyond the skull.

Friday, February 06, 2009

MindBlog's third birthday.

This Sunday will be Mindblog's 3rd birthday, the first posting was on Feb. 8, 2006. I started it after reading an article on blogging in the New York Times, and decided that I might as well pass on some of the reading and thinking that I was doing anyway. I had no idea that by now (~1,450 posts later) it would be reaching ~10,000 people a month, of which half are in the United States. I want to thank readers who have commented on the posts or sent sent me emails with further ideas.

Apply mild electric current to your head, improve your motor skills

Balakar describes experiments of Reis et al. , who

...trained two groups of 12 volunteers each to use a joystick to move a cursor as quickly and accurately as possible through an obstacle course on a computer screen. The task was difficult enough to ensure that performance would improve over five days of practice.

During the practice sessions, all participants had electrodes connected over the primary motor cortex, the part of the brain that plans and executes movements. One group was stimulated with a mild current through the connection and the other was not. After five days of practice, the group that received the current was significantly better at the task, both in speed and accuracy.

Never ending childhood...

Alison Gopnik suggests that our new scientific understanding of neural plasticity and gene regulation, along with the global spread of schooling, will let us remain children forever — or at least for much longer.

Across species, a long childhood is correlated with an evolutionary strategy that depends on flexibility, intelligence and learning. There is a developmental division of labor. Children get to learn freely about their particular environment without worrying about their own survival — caregivers look after that...We grown-ups are production and marketing. We start out as brilliantly flexible but helpless and dependent babies, great at learning everything but terrible at doing just about anything. We end up as much less flexible but much more efficient and effective adults, not so good at learning but terrific at planning and acting.

For most of human history babies and toddlers used their spectacular, freewheeling, unconstrained learning abilities to understand fundamental facts about the objects, people and language around them — the human core curriculum. At about 6 children also began to be apprentices. Through a gradual process of imitation, guidance and practice they began to master the particular adult skills of their particular culture...School, a very recent human invention, completely alters this program. Schooling replaces apprenticeship. School lets us all continue to be brilliant but helpless babies...school is also an extension of the period of infant dependence — since we don't actually do anything useful in school, other people need to take care of us — all the way up to a Ph.D. School doesn't include the gradual control and mastery of specific adult skills that we once experienced in apprenticeship. Universal and extended schooling means that the period of flexible learning and dependence can continue until we are in our thirties, while independent active mastery is increasingly delayed.

...there may be an intrinsic trade-off between flexibility and effectiveness, between the openness that we require for learning and the focus that we need to act. Child-like brains are great for learning, but not so good for effective decision-making or productive action. There is some evidence that adolescents even now have increasing difficulty making decisions and acting independently, and pathologies of adolescent action like impulsivity and anxiety are at all-time historical highs. Fundamental grown-up human skills we once mastered through apprenticeship, like cooking and caregiving itself, just can't be acquired through schooling. (Think of all those neurotic new parents who have never taken care of a child and try to make up for it with parenting books). When we are all babies for ever, who will be the parents? When we're all children who will be the grown-ups?

Thursday, February 05, 2009

Psychosocial stress inhibits prefrontal function

Wow, this piece of work is both sobering and optimistic. These imaging studies by Liston, McEwen, and Casey (full access article) show that diminished performance in an attention shifting task induced by stress correlates with reduction of functional connectivity within a frontoparietal network. These changes, however, are reversed if stress is removed. Here is their abstract:

Relatively little is known about the long-term neurobiological sequelae of chronic stress, which predisposes susceptible patients to neuropsychiatric conditions affecting the prefrontal cortex (PFC). Animal models and human neuroimaging experiments provide complementary insights, yet efforts to integrate the two are often complicated by limitations inherent in drawing comparisons between unrelated studies with disparate designs. Translating from a rodent model of chronic stress where we have shown reversible disruption of PFC function, we show that psychosocial stress induces long-lasting but reversible impairments in behavioral and functional magnetic resonance imaging (fMRI) measures of PFC function in humans. Twenty healthy adults, exposed to 1 month of psychosocial stress, confirmed by a validated rating scale, were scanned while performing a PFC-dependent attention-shifting task. One month later, they returned for a second scanning session after a period of reduced stress, and their performance was compared with a twice-scanned, matched group of low-stress controls. Psychosocial stress selectively impaired attentional control and disrupted functional connectivity within a frontoparietal network that mediates attention shifts. These effects were reversible: after one month of reduced stress, the same subjects showed no significant differences from controls. These results highlight the plasticity of PFC networks in healthy human subjects and suggest one mechanism by which disrupted plasticity may contribute to cognitive impairments characteristic of stress-related neuropsychiatric conditions in susceptible individuals.

Drinking coffee lowers dementia

A reassuring note for those of us who are coffee drinkers.

Wednesday, February 04, 2009

Synchrony and Cooperation

From Wiltermuth and Heath, slightly edited:

The decline of the bayonet and the advent of the machine gun have made marching in step a terrible, if not suicidal, combat tactic; yet armies still train by marching in step. Similarly, religions around the world incorporate synchronous singing and chanting into their rituals. Why? We suggest that acting in synchrony with others can foster cooperation within groups by strengthening group cohesion. The widespread presence of cultural rituals involving synchrony may have evolved as partial solutions to the free-rider problem, the tendency for some individuals to shoulder less than their share of the burden of producing public goods and participating in collective action.
Their abstract:
Armies, churches, organizations, and communities often engage in activities—for example, marching, singing, and dancing—that lead group members to act in synchrony with each other. Anthropologists and sociologists have speculated that rituals involving synchronous activity may produce positive emotions that weaken the psychological boundaries between the self and the group. This article explores whether synchronous activity may serve as a partial solution to the free-rider problem facing groups that need to motivate their members to contribute toward the collective good. Across three experiments, people acting in synchrony with others cooperated more in subsequent group economic exercises, even in situations requiring personal sacrifice. Our results also showed that positive emotions need not be generated for synchrony to foster cooperation. In total, the results suggest that acting in synchrony with others can increase cooperation by strengthening social attachment among group members.

Some description of the experiments:

In the first experiment an experimenter led 30 participants (60% female; mean age = 20, SD= 2.0) in groups of 3 on walks around campus. In the synchronous condition, participants walked in step. In the control condition, they walked normally. After their walk, participants completed a questionnaire designed to convince participants that they had finished the experiment....In an ostensibly separate experiment, a second experimenter conducted the Weak Link Coordination Exercise, which models situations in which group productivity is a function of the lowest level of input...the game measures expectations of cooperation.

In a second experiment groups were randomly assigned to one of four conditions: In the control condition (i.e., the no-singing, no-moving condition), participants (American students) listened to "O Canada," held a plastic cup above the table, and silently read the lyrics to the anthem. In the synchronous-singing condition, participants listened to the anthem, held the cup, and sang the words "O Canada" at the appropriate times. In the synchronous-singing-and-moving condition, participants listened to the anthem, sang the words "O Canada," and moved cups from side to side in time with the music. In the asynchronous condition, participants sang and moved cups, but participants each listened to the anthem at a different tempo, causing them to move their cups at different rates and sing "O Canada" at different times. Participants in all conditions were told that they might hear the same or different versions of "O Canada," but only participants in the asynchronous condition actually heard different versions. Participants in the two synchrony conditions cooperated more in the subsequent Weak Link Coordination Exercise described in Study 1 than did participants in the control or asynchronous conditions.

The third experiment used the same synchrony, asynchrony, and control groups as the second to show that after behaving in synchrony with others, people contribued more to a public account in a commons dilemma known as a public-goods game. Moving in synchrony boosted cooperation even when behaving cooperatively conflicted with personal self-interest.

Conceptual similarity of biological and cultural development

I found this brief essay by Brian Goodwin fascinating. I tried to reduce it to a few excerpts, but end up wanting to pass on the entire piece:

I anticipate that biology will go through a transforming revelation/revolution that is like the revolution that happened in physics with the development of quantum mechanics nearly 100 years ago. In biology this will involve the realisation that to make sense of the complexity of gene activity in development, the prevailing model of local mechanical causality will have to be abandoned. In its place we will have a model of interactive relationships within gene transcription networks that is like the pattern of interactions between words in a language, where ambiguity is essential to the creation of emergent meaning that is sensitive to cultural history and to context. The organism itself is the emergent meaning of the developmental process as embodied form, sensitive to both historical constraint within the genome and to environmental context, as we see in the adaptive creativity of evolution. What contemporary studies have revealed is that genes are not independent units of information that can be transferred between organisms to alter phenotypes, but elements of complex networks that act together in a morphogenetic process that produces coherent form and function as embodied meaning.

A major consequence that I see of this revelation in biology is the realisation that the separation we have made between human creativity as expressed in culture, and natural creativity as expressed in evolution, is mistaken. The two are much more deeply related than we have previously recognised. That humans are embedded in and dependent on nature is something that no-one can deny. This has become dramatically evident recently as our economic system has collapsed, along with the collapse of many crucial ecosystems, due to our failure to integrate human economic activity as a sustainable part of Gaian regulatory networks. We now face dramatic changes in the climate that require equally dramatic changes in our technologies connected with energy generation, farming, travel, and human life-style in general.

On the other hand, the recognition that culture is embedded in nature is not so evident but will, I believe, emerge as part of the biological revelation/revolution. Biologists will realise that all life, from bacteria to humans, involves a creative process that is grounded in natural languages as the foundation of their capacity for self-generation and continuous adaptive transformation. The complexity of the molecular networks regulating gene activity in organisms reveals a structure and a dynamic that has the self-similar characteristics and long-range order of languages. The coherent form of an organism emerges during its development as the embodied meaning of the historical genetic text, created through the process of resolving ambiguity and multiple possibilities of form into appropriate functional order that reflects sensitivity to context. Such use of language in all its manifestations in the arts and the sciences is the essence of cultural creativity.

In conclusion, I see the deep conceptual changes that are currently happening in biology as a prelude and accompaniment to the cultural changes that are occurring in culture, facilitating these and ushering in a new age of sustainable living on the planet.

Tuesday, February 03, 2009

MindBlog's second PodCast - "The Beast Within"

This second podcast (39 minutes, 17.9 MB, .mp3 format), like the first, is a reduced form of an essay on my website. It talks about those components of our human actions, feelings, and mental lives that are more similar to those of other animals than most of us realize, and notes the introspective access we have to these more simple levels of our mind. I am going to attempt to keep future podcasts in the 10-30 minute length range.

Note: I am very grateful for the feedback on my first podcast attempt last Wednesday ("The I-Illusion"). I am generating these in the .mp3 audio format using the Apple Garage Band Program. I don't want to get too immersed in the techie side of this, but would ask if any of you have a problem with this presentation, or would like to suggest a different presentation. I think I may have managed to make the podcasts available on iTunes via the Feedburner service.

I don't believe in atheists

The title of this post is the title of a new book by Chris Hedges. A reader pointed out this interesting interview with Hedges at Salon.com. He takes on "The New Atheists," who he accuses of preaching a fundamentalism as dangerous as the religious fundamentalist belief systems they attack, nudging the secular left to embrace the same kind of bigotry and chauvinism and intolerance that marks the radical Christian right. Both divide the world into "us" and "them" and fail to have empathy. One Hedges comment from the interview:

I write in the book that not believing in God is not dangerous. Not believing in sin is very dangerous. I think both the Christian right and the New Atheists in essence don't believe in their own sin, because they externalize evil. Evil is always something out there that can be eradicated. For the New Atheists, it's the irrational religious hordes. I mean, Sam Harris, at the end of his first book, asks us to consider a nuclear first strike on the Arab world. Both Hitchens and Harris defend the use of torture. Of course, they're great supporters of preemptive war, and I don't think this is accidental that their political agendas coalesce completely with the Christian right.

Incorporation of misinformation during memory reconsolidation

Chan et al. report a counter-intuitive finding. You would think that because memory retrieval is a powerful memory enhancer, recalling a witnessed event prior to receiving misinformation about it should reduce eyewitness suggestibility. They report just the opposite:

People's later memory of an event can be altered by exposure to misinformation about that event. The typical misinformation paradigm, however, does not include a recall test prior to the introduction of misinformation, contrary to what real-life eyewitnesses encounter when they report to a 911 operator or crime-scene officer. Because retrieval is a powerful memory enhancer (the testing effect), recalling a witnessed event prior to receiving misinformation about it should reduce eyewitness suggestibility. We show, however, that immediate cued recall actually exacerbates the later misinformation effect for both younger and older adults. The reversed testing effect we observed was based on two mechanisms: First, immediate cued recall enhanced learning of the misinformation; second, the initially recalled details became particularly susceptible to interference from later misinformation, a finding suggesting that even human episodic memory may undergo a reconsolidation process. These results show that real-life eyewitness memory may be even more susceptible to misinformation than is currently envisioned.

Monday, February 02, 2009

It's hard to be dignified when your name is....


The figure is from Sarah Lyall's New York Times article.

Some monday morning music

A comment on the mindblog podcast I posted last week reminded me that I haven't been posted much of my music lately. I did pass on one recording made on the Steinway upright in my snowbird condo here in Fort Lauderdale last January, but this year I've decided to wait for more recordings until I get back to Madison and my Steinway B, which has a gorgeous sound. Here is a Debussy's first Arabesque done on that instrument.

The epistemology of everything

I thought this essay was so striking that I want to pass it on in its entirety (I started to excerpt chunks, but found every sentence worthwhile, and so stopped). It is completely consonant with the ideas in my "I-Illusion" lecture and podcast.

Understanding that the outside world is really inside us and the inside world is really outside us will change everything. Both inside and outside. Why?.."There is no out there out there", physicist John Wheeler said in his attempt to explain quantum physics. All we know is how we correlate with the world. We do not really know what the world is really like, uncorrelated with us. When we seem to experience an external world that is out there, independent of us, it is something we dream up...Modern neurobiology has reached the exact same conclusion. The visual world, what we see, is an illusion, but then a very sophisticated one. There are no colours, no tones, no constancy in the "real" world, it is all something we make up. We do so for good reasons and with great survival value. Because colors, tones and constancy are expressions of how we correlate with the world...The merging of the epistemological lesson from quantum mechanics with the epistemological lesson from neurobiology attest to a very simple fact: What we percieve as being outside of us is indeed a fancy and elegant projection of what we have inside. We do make this projection as as result of interacting with something not inside, but everything we experience is inside...Is it not real? It embodies a correlation that is very real. As physicist N. David Mermin has argued, we do have correlations, but we do not know what it is that correlates, or if any correlata exists at all. It is a modern formulation of quantum pioneer Niels Bohr's view: "Physics is not about nature, it is about what we can say about nature."

So what is real, then? Inside us humans a lot of relational emotions exists. We feel affection, awe, warmth, glow, mania, belonging and refusal towards other humans and to the world as a whole. We relate and it provokes deep inner emotional states. These are real and true, inside our bodies and percieved not as "real states" of the outside world, but more like a kind of weather phenomena inside us...That raises the simple question: Where do these internal states come from? Are they an effect of us? Did we make them or did they make us? Love exists before us (most of us were conceived in an act of love). Friendship, family bonds, hate, anger, trust, distrust, all of these entities exist before the individual. They are primary. The illusion of the ego denies the fact that they are there before the ego consciously decided to love or hate or care or not. But the inner states predate the conscious ego. And they predate the bodily individual...The emotional states inside us are very, very real and the product of biological evolution. They are helpful to us in our attempt to survive. Experimental economics and behavioral sciences have recently shown us how important they are to us as social creatures: To cooperate you have to trust the other party, even though a rational analysis will tell you that both the likelihood and the cost of being cheated is very high. When you trust, you experience a physiologically detectable inner glow of pleasure. So the inner emotional state says yes. However, if you rationally consider the objects in the outside world, the other parties, and consider their trade-offs and motives, you ought to choose not to cooperate. Analyzing the outside world makes you say no. Human cooperation is dependent on our giving weight to what we experience as the inner world compared to what we experience as the outer world.

Traditionally, the culture of science has denied the relevance of the inner states. Now, they become increasingly important to understanding humans. And highly relevant when we want to build artefacts that mimic us...Soon we will be building not only Artificial Intelligence. We will be building Artificial Will. Systems with an ability to convert internal decisions and values into external change. They will be able to decide that they want to change the world. A plan inside becomes an action on the outside. So they will have to know what is inside and outside...In building these machines we ourselves will learn something that will change everything: The trick of perception is the trick of mistaking an inner world for the outside world. The emotions inside are the evolutionary reality. The things we see and hear outside are just elegant ways of imagining correlata that can explain our emotions, our correlations. We don't hear the croak, we hear the frog.

When we understand that the inner emotional states are more real than what we experience as the outside world, cooperation becomes easier. The epoch of insane mania for rational control will be over...What really changes is they way we see things, the way we experience everything. For anything to change out there you have to change everything in here. That is the epistemological situation. All spiritual traditions have been talking about it. But now it grows from the epistemology of quantum physics, neurobiology and the building of robots...We will be sitting there, building those Artificial Will-robots. Suddenly we will start laughing. There is no out there out there. It is in here. There is no in here in here. It is out there. The outside is in here. Who is there?

That laughter will change everything.