Our cooperative behavior is innate.

Nicholas Wade notes Tomasello's new book "Why We Cooperate." Helping behavior is observed in children and seems to be innate because it appears very early and before many parents start teaching children the rules of polite behavior. (The pictures shows a young child responding when an adult has dropped something.) Helping behavior can also be seen in infant chimpanzees under the right experimental conditions. Some clips:

Shared intentionality, in Dr. Tomasello’s view, is close to the essence of what distinguishes people from chimpanzees. A group of human children will use all kinds of words and gestures to form goals and coordinate activities, but young chimps seem to have little interest in what may be their companions’ minds...The shared intentionality lies at the basis of human society, Dr. Tomasello argues. From it flow ideas of norms, of punishing those who violate the norms and of shame and guilt for punishing oneself. Shared intentionality evolved very early in the human lineage, he believes, and its probable purpose was for cooperation in gathering food. Anthropologists report that when men cooperate in hunting, they can take down large game, which single hunters generally cannot do. Chimpanzees gather to hunt colobus monkeys, but Dr. Tomasello argues this is far less of a cooperative endeavor because the participants act on an ad hoc basis and do not really share their catch.

An interesting bodily reflection of humans’ shared intentionality is the sclera, or whites, of the eyes. All 200 or so species of primates have dark eyes and a barely visible sclera. All, that is, except humans, whose sclera is three times as large, a feature that makes it much easier to follow the direction of someone else’s gaze. Chimps will follow a person’s gaze, but by looking at his head, even if his eyes are closed. Babies follow a person’s eyes, even if the experimenter keeps his head still...Advertising what one is looking at could be a risk. Dr. Tomasello argues that the behavior evolved “in cooperative social groups in which monitoring one another’s focus was to everyone’s benefit in completing joint tasks.”..This could have happened at some point early in human evolution, when in order to survive, people were forced to cooperate in hunting game or gathering fruit. The path to obligatory cooperation — one that other primates did not take — led to social rules and their enforcement, to human altruism and to language.

Pre-natal androgens and risk taking...

Coates and Page follow up on a study I mentioned in an earlier post, this time examining risk taking as well as long-term profitability of traders in the City of London exchange:

Traders in the financial world are assessed by the amount of money they make and, increasingly, by the amount of money they make per unit of risk taken, a measure known as the Sharpe Ratio. Little is known about the average Sharpe Ratio among traders, but the Efficient Market Hypothesis suggests that traders, like asset managers, should not outperform the broad market. Here we report the findings of a study conducted in the City of London which shows that a population of experienced traders attain Sharpe Ratios significantly higher than the broad market. To explain this anomaly we examine a surrogate marker of prenatal androgen exposure, the second-to-fourth finger length ratio (2D:4D), which has previously been identified as predicting a trader's long term profitability. We find that it predicts the amount of risk taken by traders but not their Sharpe Ratios. We do, however, find that the traders' Sharpe Ratios increase markedly with the number of years they have traded, a result suggesting that learning plays a role in increasing the returns of traders. Our findings present anomalous data for the Efficient Markets Hypothesis.

How fear versus disgust regulate our attention.

Vermeulen et al. do a nice experiment demonstrating emotional effects on our attention, using the attentional blink to show that our noticing a rapidly presented second irrelevant input after seeing a fearful face is inhibited more than after we have seen a disgusting face.

It is well known that facial expressions represent important social cues. In humans expressing facial emotion, fear may be configured to maximize sensory exposure (e.g., increases visual input) whereas disgust can reduce sensory exposure (e.g., decreases visual input). To investigate whether such effects also extend to the attentional system, we used the “attentional blink” (AB) paradigm. Many studies have documented that the second target (T2) of a pair is typically missed when presented within a time window of about 200–500 ms from the first to-be-detected target (T1; i.e., the AB effect). It has recently been proposed that the AB effect depends on the efficiency of a gating system which facilitates the entrance of relevant input into working memory, while inhibiting irrelevant input. Following the inhibitory response on post T1 distractors, prolonged inhibition of the subsequent T2 is observed. We hypothesized that processing facial expressions of emotion would influence this attentional gating. Fearful faces would increase but disgust faces would decrease inhibition of the second target...We found that processing fear faces impaired the detection of T2 to a greater extent than did the processing disgust faces. This finding implies emotion-specific modulation of attention.

A dopamine receptor gene and emotional control

Blasi et al. note that variation of the Dopamine D₂ receptor gene is associated with emotional control as well as brain activity and connectivity during human emotion processing:

Personality traits related to emotion processing are, at least in part, heritable and genetically determined. Dopamine D₂ receptor signaling is involved in modulation of emotional behavior and activity of associated brain regions such as the amygdala and the prefrontal cortex. An intronic single nucleotide polymorphism within the D₂ receptor gene (DRD2) (rs1076560, guanine > thymine or G > T) shifts splicing of the two protein isoforms (D₂ short, mainly presynaptic, and D₂ long) and has been associated with modulation of memory performance and brain activity. Here, our aim was to investigate the association of DRD2 rs1076560 genotype with personality traits of emotional stability and with brain physiology during processing of emotionally relevant stimuli. DRD2 genotype and Big Five Questionnaire scores were evaluated in 134 healthy subjects demonstrating that GG subjects have reduced "emotion control" compared with GT subjects. Functional magnetic resonance imaging in a sample of 24 individuals indicated greater amygdala activity during implicit processing and greater dorsolateral prefrontal cortex (DLPFC) response during explicit processing of facial emotional stimuli in GG subjects compared with GT. Other results also demonstrate an interaction between DRD2 genotype and facial emotional expression on functional connectivity of both amygdala and dorsolateral prefrontal regions with overlapping medial prefrontal areas. Moreover, rs1076560 genotype is associated with differential relationships between amygdala/DLPFC functional connectivity and emotion control scores. These results suggest that genetically determined D₂ signaling may explain part of personality traits related to emotion processing and individual variability in specific brain responses to emotionally relevant inputs.

Psyche is back.

I've been meaning to mention that the official journal of the ASSC ( the Association for the Scientific Study of Consciousness), Psyche, is now back in a new form with its articles available for free PDF download.

Ongoing Victim Suffering Increases Prejudice

Imhoff and Banse empirically test the secondary-anti-Semitism theory, which suggests that every reminder of the German atrocities and the victims' suffering still evokes aversive feelings of guilt and thus increases a defensive anti-Semitism—even in Germans born decades after 1945. (Hence the famous quip from Israeli psychoanalyst Zvi Rex that "The Germans will never forgive the Jews for Auschwitz.") The bogus pipeline (BPL) mentioned is a classic approach for revealing socially undesirable attitudes or behavior in which participants are led to believe that they are being monitored by a psychophysiological apparatus that can detect untruthful responses. Previous research has shown that individuals disclose more socially undesirable behaviors and attitudes under BPL conditions than when the BPL is not employed. Here is the abstract:

Some people have postulated that the perception of Jews' ongoing suffering from past atrocities can result in an increase in anti-Semitism. This postulated secondary anti-Semitism is compatible with a number of psychological theories, but until now there has been no empirical evidence in support of this notion. The present study provides the first evidence that ongoing suffering evokes an increase in prejudice against the victims. However, this effect became apparent only if respondents felt obliged to respond truthfully because of a bogus pipeline (BPL); without this constraint, the perception of ongoing victim suffering led to a socially desirable reduction in self-reported prejudice. The validity of the BPL manipulation was confirmed by the finding that it moderated the relation between explicit and implicit anti-Semitism, as measured with an affect misattribution procedure.

Universality in distinguishing natural from artificial, and in color naming.

Interesting observations by Biederman et al.:

Many of the phenomena underlying shape recognition can be derived from the greater sensitivity to nonaccidental properties of an image (e.g., whether a contour is straight or curved), which are invariant to orientation in depth, than to the metric properties of an image (e.g., a contour's degree of curvature), which can vary with orientation. What enables this sensitivity? One explanation is that it derives from people's immersion in a manufactured world in which simple, regular shapes distinguished by nonaccidental properties abound (e.g., a can, a brick), and toddlers are encouraged to play with toy shape sorters. This report provides evidence against this explanation. The Himba, a seminomadic people living in a remote region of northwestern Namibia where there is little exposure to regular, simple artifacts, were virtually identical to Western observers in their greater sensitivity to nonaccidental properties than to metric properties of simple shapes.

Also, on the subject of human universals, Lindsey and Brown note universal motifs in color naming.

Obama, Afganistan, and the emotional brain

David Eagleman does a nice essay on how Obama's withdrawal timetable decisions relate to the psychology of uncertainty, expectation, and reward.

Watch the live dissection of a famous brain.

See Benedict's Carey's article on Henry Molaison — known during his lifetime only as H.M., to protect his privacy — who lost the ability to form new memories after a brain operation in 1953, and over the next half century became the most studied patient in brain science. Here is the dissection in progress:

We have reached the corpus callosum. The team is resting for the night. The brain will be safe surrounded by our chillers until tomorrow morning. The cutting will resume again at 8AM PST.

Tomorrow will be a big day - We will try to cover the medial temporal lobes and the area surrounding the hippocampus.

Hearing with both your skin and your ears

Gick and Derrick offer a fascinating example of cross modal sensory perception, demonstrating 'aero-tactile' integration in speech perception:

...we show that perceivers integrate naturalistic tactile information during auditory speech perception without previous training. Drawing on the observation that some speech sounds produce tiny bursts of aspiration (such as English 'p'), we applied slight, inaudible air puffs on participants' skin at one of two locations: the right hand or the neck. Syllables heard simultaneously with cutaneous air puffs were more likely to be heard as aspirated (for example, causing participants to mishear 'b' as 'p'). These results demonstrate that perceivers integrate event-relevant tactile information in auditory perception in much the same way as they do visual information.

The syllables included “pa” and “ta,” which produce a brief puff from the mouth when spoken, and “da” and “ba,” which do not produce puffs. When listeners heard “da” or “ba” while a puff of air was blown onto their skin, they perceived the sound as “ta” or “pa.” It seems likely that this integration of different sensory cues is innate, for subjects were completely unaware that they were doing it.

Buttress self esteem - reduce aggression

Here is a fascinating study from Thomaes et al. They conducted a randomized field trial in the Netherlands to assess the efficacy of a brief affirmation exercise designed to buttress self-esteem. Before the intervention, aggressive behavior was prevalent among the individuals who scored high on the narcissism scale and low on self-esteem. Afterward, acts of aggression decreased even though the individual levels of self-esteem (both high and low) were unchanged. Here is the abstract:

Narcissistic individuals are prone to become aggressive when their egos are threatened. We report a randomized field experiment that tested whether a social-psychological intervention designed to lessen the impact of ego threat reduces narcissistic aggression. A sample of 405 young adolescents (mean age = 13.9 years) were randomly assigned to complete either a short self-affirmation writing assignment (which allowed them to reflect on their personally important values) or a control writing assignment. We expected that the self-affirmation would temporarily attenuate the ego-protective motivations that normally drive narcissists' aggression. As expected, the self-affirmation writing assignment reduced narcissistic aggression for a period of a school week, that is, for a period up to 400 times the duration of the intervention itself. These results provide the first empirical demonstration that buttressing self-esteem (as opposed to boosting self-esteem) can be effective at reducing aggression in at-risk youth.

How's Your Gaydar?

From the random samples section of the Nov. 27 issue of Science:

Can you guess a woman's sexual orientation just from her face? Surprisingly, your guess would be better than flipping a coin....Psychologist Nicholas Rule of Tufts University in Medford, Massachusetts, and colleagues asked 21 college students the same question about 192 photos—cropped to eliminate hair and ears—of gay and straight women from dating Web sites. The undergraduates guessed right 64% of the time and scored better than chance—53%—even when they saw only the women's eyes, the researchers report this month in the Journal of Experimental Social Psychology. In 2008, Rule reported similar results with male faces.

The process appears to be unconscious, Rule says. Subjects were more accurate when told to make snap judgments than when they pondered their decisions. Rule believes subtle differences in facial muscles caused by habitual expressions may be the clue. Previous work has shown that homosexuals tend to adopt facial expressions more typical of the opposite sex. The results show that we know much more about others from snippets of information than we realize, says psychologist David Kenny of the University of Connecticut, Storrs.

Here is the abstract from Rule et al.

Whereas previous work has shown that male sexual orientation can be accurately and rapidly perceived from the human face and its individual features, no study has examined the judgment of female sexual orientation. To fill this gap, the current work examined the accuracy, speed, and automaticity of judgments of female sexual orientation from the face and from facial features. Study 1 showed that female sexual orientation could be accurately judged from the face and from just eyes without brows and limited to the outer canthi. Study 2 then examined the speed and efficiency of these judgments, showing that judgments of the faces following very brief, near subliminal (40 ms) exposures were significantly better than chance guessing. Finally, Study 3 tested the automaticity of judgments of female sexual orientation by examining the effects of deliberation on accuracy. Participants who made snap judgments of female sexual orientation were significantly more accurate than participants who made thoughtful and deliberated judgments. These data therefore evidence a robust, reliable, and automatic capacity for extracting information about female sexual orientation from nonverbal cues in the face.

Dietary specialization: man-eating lions

I thought this fascinating bit of work was a hoot. Two famous man-eating lions in the Tsavo region of Kenya were identified and shot in 1989, and these guys analyzed their diet from studies of the isotopes in their bones:

Cooperation is the cornerstone of lion social behavior. In a notorious case, a coalition of two adult male lions from Tsavo, southern Kenya, cooperatively killed dozens of railway workers in 1898. The “man-eaters of Tsavo” have since become the subject of numerous popular accounts, including three Hollywood films. Yet the full extent of the lions' man-eating behavior is unknown; estimates range widely from 28 to 135 victims. Here we use stable isotope ratios to quantify increasing dietary specialization on novel prey during a time of food limitation. For one lion, the δ¹³C and δ¹⁵N values of bone collagen and hair keratin (which reflect dietary inputs over years and months, respectively) reveal isotopic changes that are consistent with a progressive dietary specialization on humans. These findings not only support the hypothesis that prey scarcity drives individual dietary specialization, but also demonstrate that sustained dietary individuality can exist within a cooperative framework. The intensity of human predation (up to 30% reliance during the final months of 1898) is also associated with severe craniodental infirmities, which may have further promoted the inclusion of unconventional prey under perturbed environmental conditions.



The man-eaters of Tsavo and a Taita ancestral shrine. (A) Lieutenant Colonel J. H. Patterson and lion FMNH 23970 shot December 9, 1898 (16) (FMNH photo archives no. z93658, Field Museum of Natural History). (B) Articulated jaws of FMNH 23970 revealing a fractured lower right canine (and subsequent root-tip abscess), missing lower incisors, supererupted upper right incisors, and rotation and malocclusion of the upper right canine. Cranial asymmetry of 23970 occurred after injury and before death. (C) Lion FMNH 23969 shot December 29, 1898. (D) Articulated jaws of FMNH 23969, revealing a fractured upper left carnassial with a double pulp exposure. (E) A Taita ancestral shrine photographed in 1929 by L. S. B. Leakey. Such a shrine results from the unusual funerary practices of the Taita; after approximately 1 year of burial in a seated position, skulls are exhumed, severed, and enshrined in ancestral caves or rock shelters.

Facial plus vocal emotion - watching the brain's enhanced response

From Hagan et al:

An influential neural model of face perception suggests that the posterior superior temporal sulcus (STS) is sensitive to those aspects of faces that produce transient visual changes, including facial expression. Other researchers note that recognition of expression involves multiple sensory modalities and suggest that the STS also may respond to crossmodal facial signals that change transiently. Indeed, many studies of audiovisual (AV) speech perception show STS involvement in AV speech integration. Here we examine whether these findings extend to AV emotion. We used magnetoencephalography to measure the neural responses of participants as they viewed and heard emotionally congruent fear and minimally congruent neutral face and voice stimuli. We demonstrate significant supra-additive responses (i.e., where AV > [unimodal auditory + unimodal visual]) in the posterior STS within the first 250 ms for emotionally congruent AV stimuli. These findings show a role for the STS in processing crossmodal emotive signals.

Dieting, compulsive eating, and brain stress.

An interesting piece from Cottone et al:

Dieting to control body weight involves cycles of deprivation from palatable food that can promote compulsive eating. The present study shows that rats withdrawn from intermittent access to palatable food exhibit overeating of palatable food upon renewed access and an affective withdrawal-like state characterized by corticotropin-releasing factor-1 (CRF1) receptor antagonist-reversible behaviors, including hypophagia, motivational deficits to obtain less palatable food, and anxiogenic-like behavior. Withdrawal was accompanied by increased CRF expression and CRF1 electrophysiological responsiveness in the central nucleus of the amygdala. We propose that recruitment of anti-reward extrahypothalamic CRF-CRF1 systems during withdrawal from palatable food, analogous to abstinence from abused drugs, may promote compulsive selection of palatable food, undereating of healthier alternatives, and a negative emotional state when intake of palatable food is prevented.

Neural architecture of music-evoked autobiographical memories

Interesting work (open access article) from Janata:

The medial prefrontal cortex (MPFC) is regarded as a region of the brain that supports self-referential processes, including the integration of sensory information with self-knowledge and the retrieval of autobiographical information. I used functional magnetic resonance imaging and a novel procedure for eliciting autobiographical memories with excerpts of popular music dating to one's extended childhood to test the hypothesis that music and autobiographical memories are integrated in the MPFC. Dorsal regions of the MPFC (Brodmann area 8/9) were shown to respond parametrically to the degree of autobiographical salience experienced over the course of individual 30 s excerpts. Moreover, the dorsal MPFC also responded on a second, faster timescale corresponding to the signature movements of the musical excerpts through tonal space. These results suggest that the dorsal MPFC associates music and memories when we experience emotionally salient episodic memories that are triggered by familiar songs from our personal past. MPFC acted in concert with lateral prefrontal and posterior cortices both in terms of tonality tracking and overall responsiveness to familiar and autobiographically salient songs. These findings extend the results of previous autobiographical memory research by demonstrating the spontaneous activation of an autobiographical memory network in a naturalistic task with low retrieval demands.

Neural correlates of detecting wrong notes in advance.

I'm always fascinating by studies on the brains of pianists (like myself). This from Ruiz et al:

Music performance is an extremely rapid process with low incidence of errors even at the fast rates of production required. This is possible only due to the fast functioning of the self-monitoring system. Surprisingly, no specific data about error monitoring have been published in the music domain. Consequently, the present study investigated the electrophysiological correlates of executive control mechanisms, in particular error detection, during piano performance. Our target was to extend the previous research efforts on understanding of the human action-monitoring system by selecting a highly skilled multimodal task. Pianists had to retrieve memorized music pieces at a fast tempo in the presence or absence of auditory feedback. Our main interest was to study the interplay between auditory and sensorimotor information in the processes triggered by an erroneous action, considering only wrong pitches as errors. We found that around 70 ms prior to errors a negative component is elicited in the event-related potentials and is generated by the anterior cingulate cortex. Interestingly, this component was independent of the auditory feedback. However, the auditory information did modulate the processing of the errors after their execution, as reflected in a larger error positivity (Pe). Our data are interpreted within the context of feedforward models and the auditory–motor coupling.

Nutrition, brain aging, and neurodegeneration

Joseph et al. offer a review of recent work showing that dietary changes favoring berry fruit, nut, fish oil, and curcumin intake, as well as and caloric restriction mimetics (such as resveratrol) may provide beneficial effects in aging and prevent or delay the onset of neurodegenerative diseases such as Alzheimer disease. While many of the mechanisms for the beneficial effects of these nutritional interventions have yet to be discerned, it is clear that they involve decreases in oxidative/inflammatory stress signaling, increases in protective signaling, and may even involve hormetic effects to protect against the two major villains of aging, oxidative and inflammatory stressors. (Hormetic is a term used to describe generally-favorable biological responses to low exposures to toxins and other stressors.)

The fMRI of understanding others' regret.

Rizzolatti and colleagues carry the mirror neuron story to an even higher level in a study of regret:

Previous studies showed that the understanding of others' basic emotional experiences is based on a “resonant” mechanism, i.e., on the reactivation, in the observer's brain, of the cerebral areas associated with those experiences. The present study aimed to investigate whether the same neural mechanism is activated both when experiencing and attending complex, cognitively-generated, emotions. A gambling task and functional-Magnetic-Resonance-Imaging (fMRI) were used to test this hypothesis using regret, the negative cognitively-based emotion resulting from an unfavorable counterfactual comparison between the outcomes of chosen and discarded options. Do the same brain structures that mediate the experience of regret become active in the observation of situations eliciting regret in another individual? Here we show that observing the regretful outcomes of someone else's choices activates the same regions that are activated during a first-person experience of regret, i.e. the ventromedial prefrontal cortex, anterior cingulate cortex and hippocampus. These results extend the possible role of a mirror-like mechanism beyond basic emotions.

The religious wars

In a NYTimes OpEd piece appropriate to yesterday's Thanksgiving rituals Kristof notes a new crop of books on religion that that he feels are less combative and more thoughtful than extreme fundamentalist (The "Left Behind" novels) or atheist (Dawkins, Harris, Hitchens) efforts.

One of these is “The Evolution of God,” by Robert Wright, who explores how religions have changed — improved — over the millennia. He notes that God, as perceived by humans, has mellowed from the capricious warlord sometimes depicted in the Old Testament who periodically orders genocides...Karen Armstrong’s “The Case for God,” likewise doesn’t posit a Grandpa-in-the-Sky; rather, she sees God in terms of an ineffable presence that can be neither proven nor disproven in any rational sense. To Ms. Armstrong, faith belongs to the realm of life’s mysteries, beyond the world of reason, and people on both sides of the “God gap” make the mistake of interpreting religious traditions too literally...“The Faith Instinct,” by...Nicholas Wade, suggests a reason for the durability of faith: humans may be programmed for religious belief, because faith conferred evolutionary advantages in primitive times. That doesn’t go to the question of whether God exists, but it suggests that religion in some form may be with us for eons to come.