More on the science of morality - baby morals.

Sam Harris deals with the massive (mostly critical) response to the TED lecture which I pointed to in my March 30 post, in which he argues for a natural and scientific basis for morality.  And,  Paul Bloom discusses observations on very young human infants that provide very strong evidence for our having an innate primitive moral capacity that is refined by individual and group interactions starting in the first year after birth .

Nasal attraction

Olsson and Laska find an exception to the generalization that women sense chemicals better than men. Men are better at detecting the lily-of-the-valley flower smell of the compound bourgeonal. This same compound is a powerful chemical attractant for male sperm cells. Because the olfactory receptors on sperm cells are also expressed in the human nose, and selective pressure for keener receptors would act on men but not on women, it makes sense that men are more sensitive to the sperm attractant.

Recent studies have shown that sperm chemotaxis critically involves the human olfactory receptor OR1D2, which is activated by the aromatic aldehyde bourgeonal. Given that both natural and sexual selection may act upon the expression of receptors, we hypothesized that human males are more sensitive than human females for bourgeonal. Using a 3-alternative forced-choice test procedure, olfactory detection thresholds were determined for a total of 500 subjects, 250 males, and 250 females between 18 and 40 years of age. We found that male subjects detected bourgeonal at significantly lower concentrations (mean value: 13 ppb) compared with female subjects (mean value: 26 ppb), whereas no such gender difference in olfactory sensitivity was found with helional, a structural analog of bourgeonal, and with n-pentyl acetate, an aliphatic ester, which were tested in parallel. Males and females did not differ in their frequency of specific anosmia for any of the 3 odorants. The frequency distributions of olfactory detection thresholds were monomodal with all 3 odorants in both genders. Olfactory detection thresholds did not differ significantly between pre- and postovulatory females with any of the 3 odorants. To the best of our knowledge, this is the first study ever to find a human male superiority in olfactory sensitivity. Single nucleotide polymorphisms and/or copy number variations in genes coding for olfactory receptors may be the proximate cause for our finding, whereas a gender difference in the behavioral relevance of bourgeonal may be the ultimate cause.

Eipgenetics and cognitive aging

Aging-related cognitive decline begins for most of us when we are in our late 40s.  Deterioration is mosty pronounced the ability to recall facts and experiences (declarative memory) and has been associated with aberrant changes in gene expression in the brain's hippocampus and frontal lobe. Peleg et al. now find support for an emerging hypothesis that changes in the epigenetic modification of chromatin in the adult central nervous system drive cognitive decline. They show that restoring a reaction that places acetyl groups on the histone proteins that regulate gene expression reinstates the expression of learning-induced genes.

As the human life span increases, the number of people suffering from cognitive decline is rising dramatically. The mechanisms underlying age-associated memory impairment are, however, not understood. Here we show that memory disturbances in the aging brain of the mouse are associated with altered hippocampal chromatin plasticity. During learning, aged mice display a specific deregulation of histone H4 lysine 12 (H4K12) acetylation and fail to initiate a hippocampal gene expression program associated with memory consolidation. Restoration of physiological H4K12 acetylation reinstates the expression of learning-induced genes and leads to the recovery of cognitive abilities. Our data suggest that deregulated H4K12 acetylation may represent an early biomarker of an impaired genome-environment interaction in the aging mouse brain.

More on creativity and the brain

This past Saturday's NYTimes had an article featuring work by Rex Jung which was the subject of last Tuesday's post. A bit facile and simplistic, but I thought I would pass on some of the eye-catching graphics supplied by researchers:

Images from brain research conducted by the Mind Research Network. While intelligence and skill are associated with the fast and efficient firing of neurons in the brain, subjects who tested high in creativity had thinner white matter and connecting axons that slow nerve traffic. In these images, the green tracks show the white matter being analyzed. The yellow and red spots show where creativity corresponds with slower nerve traffic. The blue areas show where “openness to experience,” associated with creativity, corresponds with slower nerve traffic. (from Jung).

Left, before an insight, activity drops in the visual cortex; right, in the “aha! moment,” activity in the right temporal lobe spikes. (from Ohn Kounios, Drexel University)

Chimps have tools for sex

Here is a great item from Tierney in this past Tuesday's NYTimes Science section. With the use of about 20 different tools having been documented in different groups of chimpanzees, now a 'come hither' tool for a male trying to get a female to mate has been recorded.

The male will pluck a leaf, or a set of leaves, and sit so the female can see him. He spreads his legs so the female sees the erection, and he tears the leaf bit by bit down the midvein of the leaf (making a rasping noise), dropping the pieces as he detaches them. Sometimes he’ll do half a dozen leaves until she notices.,,,And then?...Presumably she sees the erection and puts two and two together, and if she’s interested, she’ll typically approach and present her back side, and then they’ll mate.

...you might see this chimp as the equivalent of a human (wearing pants, one hopes) trying to attract women by driving around with a car thumping out 120-decibel music... But it would be fairer to compare the clipped leaf with the most popular human sex tool...the vibrator, considered taboo a few decades ago, has become one of the most common household appliances in the United States....

William's syndrome: Disappearance of racism along with social fear.

Meyer-Lindenberg and collaborators report the interesting observation that racial stereotyping, but not gender stereotyping, disappears in children with Williams syndrome (who lack social fear):

Stereotypes — often implicit attributions to an individual based on group membership categories such as race, religion, age, gender, or nationality — are ubiquitous in human interactions. Even three-year old children clearly prefer their own ethnic group and discriminate against individuals of different ethnicities. While stereotypes may enable rapid behavioural decisions with incomplete information, such biases can lead to conflicts and discrimination, especially because stereotypes can be implicit and automatic, making an understanding of the origin of stereotypes an important scientific and socio-political topic. An important process invoked by out-groups is social fear. A unique opportunity to study the contribution of this mechanism to stereotypes is afforded by individuals with the microdeletion disorder Williams syndrome (WS), in which social fear is absent, leading to an unusually friendly, high approachability behaviour, including towards strangers. Here we show that children with WS lack racial stereotyping, though they retain gender stereotyping, compared to matched typically developing children. Our data indicate that mechanisms for the emergence of gender versus racial bias are neurogenetically dissociable. Specifically, because WS is associated with reduced social fear, our data support a role of social fear processing in the emergence of racial, but not gender, stereotyping.

Our brain as a cognitive miser - where decision costs are registered.

McGuire1 and Botvinick show that lateral prefrontal cortex (LPFC) is where the costs of cognitively demanding decisions are reflected. From their introduction:

...decision-makers balance a motive to maximize gains with a motive to minimize decision costs. The concept of decision costs helps explain such behavioral phenomena as effort-accuracy tradeoffs, reliance on fast and frugal heuristics, failure to consider all available alternatives, effort discounting, the use of stereotypes, and salutary effects of monetary incentives. Amplified decision costs might play a role in clinical depression and chronic fatigue syndrome. This idea is related to the view that decision-making consumes a limited resource, and, more generally, that humans act as cognitive misers.

Their abstract: (Experiment 1 elicited repeated self-reports of experienced decision costs, measured in terms of participants’ rated desire to avoid the task. Experiment 2 sought to confirm the relevance of LPFC to the evaluation of decision costs, with costs measured directly in terms of observed avoidance behavior.)

Human choice behavior takes account of internal decision costs: people show a tendency to avoid making decisions in ways that are computationally demanding and subjectively effortful. Here, we investigate neural processes underlying the registration of decision costs. We report two functional MRI experiments that implicate lateral prefrontal cortex (LPFC) in this function. In Experiment 1, LPFC activity correlated positively with a self-report measure of costs as this measure varied over blocks of simple decisions. In Experiment 2, LPFC activity also correlated with individual differences in effort-based choice, taking on higher levels in subjects with a strong tendency to avoid cognitively demanding decisions. These relationships persisted even when effects of reaction time and error were partialled out, linking LPFC activity to subjectively experienced costs and not merely to response accuracy or time on task. In contrast to LPFC, dorsomedial frontal cortex—an area widely implicated in performance monitoring—showed no relationship to decision costs independent of overt performance. Previous work has implicated LPFC in executive control. Our results thus imply that costs may be registered based on the degree to which control mechanisms are recruited during decision-making.

Slowing down the brain may enhance creativity.

Geddes points to work by Jung et al. that suggest an inverse correlation in human subjects between brain connectivity, reflected by the amount of the cortical myelin that sheathes nerve tracts (see the illustrations here), and creativity, assayed by a "composite creativity index."  If  less myelin corresponds to slower communication between regions of the brain, this could suggest that slowing down our brains makes them more creative:

That creativity and psychopathology are somehow linked remains a popular but controversial idea in neuroscience research. Brain regions implicated in both psychosis-proneness and creative cognition include frontal projection zones and association fibers. In normal subjects, we have previously demonstrated that a composite measure of divergent thinking (DT) ability exhibited significant inverse relationships in frontal lobe areas with both cortical thickness and metabolite concentration of N-acetyl-aspartate (NAA). These findings support the idea that creativity may reside upon a continuum with psychopathology. Here we examine whether white matter integrity, assessed by Fractional Anisotropy (FA), is related to two measures of creativity (Divergent Thinking and Openness to Experience). Based on previous findings, we hypothesize inverse correlations within fronto-striatal circuits. Seventy-two healthy, young adult (18–29 years) subjects were scanned on a 3 Tesla scanner with Diffusion Tensor Imaging. DT measures were scored by four raters (α = .81) using the Consensual Assessment Technique, from which a composite creativity index (CCI) was derived. We found that the CCI was significantly inversely related to FA within the left inferior frontal white matter (t = 5.36, p = .01), and Openness was inversely related to FA within the right inferior frontal white matter (t = 4.61, p = .04). These findings demonstrate an apparent overlap in specific white matter architecture underlying the normal variance of divergent thinking, openness, and psychotic-spectrum traits, consistent with the idea of a continuum.

Emotions can persist longer than memory of their induction.

Feinstein et al. provide evidence that a feeling of emotion can endure beyond the conscious recollection for the events that initially triggered the emotion:

Can the experience of an emotion persist once the memory for what induced the emotion has been forgotten? We capitalized on a rare opportunity to study this question directly using a select group of patients with severe amnesia following circumscribed bilateral damage to the hippocampus. The amnesic patients underwent a sadness induction procedure (using affectively-laden film clips) to ascertain whether their experience of sadness would persist beyond their memory for the sadness-inducing films. The experiment showed that the patients continued to experience elevated levels of sadness well beyond the point in time at which they had lost factual memory for the film clips. A second experiment using a happiness induction procedure yielded similar results, suggesting that both positive and negative emotional experiences can persist independent of explicit memory for the inducing event. These findings provide direct evidence that a feeling of emotion can endure beyond the conscious recollection for the events that initially triggered the emotion.

Embodyment: a two-minute powerful pose raises your testosterone levels

I pass on this fascinating item from a mindblog reader who has pointed out a number of other interesting articles to me. The article by Carnay, Cuddy, and Yap is titled "Power Posing: Brief Nonverbal Displays Affect Neuroendocrine Levels and Risk Tolerance."

Hey, I tried it, puffing up my chest and letting my shoulders rest back for two minutes left me feeling way more strong and assertive (now....where can I find a cheap saliva testosterone  home test kit...).

Here is the abstract:

Humans and other animals express power through open, expansive postures, and powerlessness through closed, constrictive postures. But can these postures actually cause power? As predicted, results revealed that posing in high-power (vs. low-power) nonverbal displays caused neuroendocrine and behavioral changes for both male and female participants: High-power posers experienced elevations in testosterone, decreases in cortisol, and increased feelings of power and tolerance for risk; low-power posers exhibited the opposite pattern. In short, posing in powerful displays caused advantaged and adaptive psychological, physiological, and behavioral changes — findings that suggest that embodiment extends beyond mere thinking and feeling, to physiology and subsequent behavioral choices. That a person can, via a simple two-minute pose, embody power and instantly become more powerful has real-world, actionable implications.

Click here for PDF of article to appear in Psychological Science

Evaluating effects of genes and environment on early reading.

Work from Taylor et al. studying mono- and dizygotic twins in kindergarten through 5th grade suggests, not suprisingly, that that better teachers allow children to fulfill their genetic potential:

Children’s reading achievement is influenced by genetics as well as by family and school environments. The importance of teacher quality as a specific school environmental influence on reading achievement is unknown. We studied first- and second-grade students in Florida from schools representing diverse environments. Comparison of monozygotic and dizygotic twins, differentiating genetic similarities of 100% and 50%, provided an estimate of genetic variance in reading achievement. Teacher quality was measured by how much reading gain the non-twin classmates achieved. The magnitude of genetic variance associated with twins’ oral reading fluency increased as the quality of their teacher increased. In circumstances where the teachers are all excellent, the variability in student reading achievement may appear to be largely due to genetics. However, poor teaching impedes the ability of children to reach their potential.

When do human groups form states?

Spencer suggests that human states evolve (without contact with any preexisting states) when the area controlled by a group becomes larger than a day's round trip from the capital:

A major research problem in anthropology is the origin of the state and its bureaucratic form of governance. Of particular importance for evaluating theories of state origins are cases of primary state formation, whereby a first-generation state evolves without contact with any preexisting states. A general model of this process, the territorial-expansion model, is presented and assessed with archaeological data from six areas where primary states emerged in antiquity: Mesoamerica, Peru, Egypt, Mesopotamia, the Indus Valley, and China. In each case, the evidence shows a close correspondence in time between the first appearance of state institutions and the earliest expansion of the state's political-economic control to regions lying more than a day's round-trip from the capital. Although additional research will add detail and clarity to the empirical record, the results to date are consistent with the territorial-expansion model, which argues that the success of such long-distance expansion not only demanded the bureaucratization of central authority but also helped provide the resources necessary to underwrite this administrative transformation.

Do brain training programs work?

ScienceNow reports an interesting tussle over the effectiveness of brain training programs. BBC producers contacted Adrian Owen at the MRC Cognition and Brain Sciences Unit in Cambridge, U.K., to help design an experiment to test the efficacy of computer brain training exercises and tested them in 11,430 healthy adults who registered on a Web site set up by the BBC. One group trained on a program that emphasized reasoning and problem-solving skills, and another group trained on a program that emphasized different skills, including short-term memory and attention. A third, control group, essentially did busywork, hunting for answers to general knowledge questions on the Internet. All participants were asked to "train" for at least 10 minutes, three times a week for 6 weeks, and all received a battery of cognitive tests before and after this 6-week period....Not surprisingly, people in both training groups got better at the tasks they actually practiced. But that's as far as it went - none of the brain-training tasks transferred to other mental or cognitive abilities beyond what had been specifically practiced.

These conclusion are contested by Klingberg, who has published one of the few studies demonstrating benefits of training can generalize beyond a specific task. He notes subjects were trained only three hours in total.

I'm a bit puzzled over why the work of Jaeggi et al. showing the effects of short term memory training on general intelligence, which I have mentioned previously, was not mentioned.

Old age improves reasoning about social conflicts

Interesting observation from Grossmann et al.:

It is well documented that aging is associated with cognitive declines in many domains. Yet it is a common lay belief that some aspects of thinking improve into old age. Specifically, older people are believed to show better competencies for reasoning about social dilemmas and conflicts. Moreover, the idea of aging-related gains in wisdom is consistent with views of the aging mind in developmental psychology. However, to date research has provided little evidence corroborating this assumption. We addressed this question in two studies, using a representative community sample. We asked participants to read stories about intergroup conflicts and interpersonal conflicts and predict how these conflicts would unfold. We show that relative to young and middle-aged people, older people make more use of higher-order reasoning schemes that emphasize the need for multiple perspectives, allow for compromise, and recognize the limits of knowledge. Our coding scheme was validated by a group of professional counselors and wisdom researchers. Social reasoning improves with age despite a decline in fluid intelligence. The results suggest that it might be advisable to assign older individuals to key social roles involving legal decisions, counseling, and intergroup negotiations. Furthermore, given the abundance of research on negative effects of aging, this study may help to encourage clinicians to emphasize the inherent strengths associated with aging.

Internet enhancing, not diminishing, the public square.

Some interesting points from David Brooks, noting a study by Gentzkow and Shapiro which counters the prevailing assumption that the internet has created a collection of information cocoons which people occupy to confirm their existing prejudices:

...they tracked how people of different political views move around the Web...The study measures the people who visit sites, not the content inside...a person who visited only Fox News would have more overlap with conservatives than 99 percent of Internet news users. A person who only went to The Times’s site would have more liberal overlap than 95 percent of users....the core finding is that most Internet users do not stay within their communities. Most people spend a lot of time on a few giant sites with politically integrated audiences, like Yahoo News.

But even when they leave these integrated sites, they often go into areas where most visitors are not like themselves. People who spend a lot of time on Glenn Beck’s Web site are more likely to visit The New York Times’s Web site than average Internet users. People who spend time on the most liberal sites are more likely to go to foxnews.com than average Internet users. Even white supremacists and neo-Nazis travel far and wide across the Web....Gentzkow and Shapiro found that the Internet is actually more ideologically integrated than old-fashioned forms of face-to-face association — like meeting people at work, at church or through community groups. You’re more likely to overlap with political opponents online than in your own neighborhood.

...Looking at a site says nothing about how you process it or the character of attention you bring to it. It could be people spend a lot of time at their home sites and then go off on forays looking for things to hate. But it probably does mean they are not insecure and they are not sheltered....If this study is correct, the Internet will not produce a cocooned public square, but a free-wheeling multilayered Mad Max public square. The study also suggests that if there is increased polarization (and there is), it’s probably not the Internet that’s causing it.

How pain impairs cognition

Ji et al. use an animal model of arthritis pain to show that pain-related cognitive deficits result from amygdala-driven impairment of medial prefrontal cortical (mPFC) function.

Oxytocin enhances social learning as well as empathy.

From Hurlemann et al.:

Oxytocin (OT) is becoming increasingly established as a prosocial neuropeptide in humans with therapeutic potential in treatment of social, cognitive, and mood disorders. However, the potential of OT as a general facilitator of human learning and empathy is unclear. The current double-blind experiments on healthy adult male volunteers investigated first whether treatment with intranasal OT enhanced learning performance on a feedback-guided item–category association task where either social (smiling and angry faces) or nonsocial (green and red lights) reinforcers were used, and second whether it increased either cognitive or emotional empathy measured by the Multifaceted Empathy Test. Further experiments investigated whether OT-sensitive behavioral components required a normal functional amygdala. Results in control groups showed that learning performance was improved when social rather than nonsocial reinforcement was used. Intranasal OT potentiated this social reinforcement advantage and greatly increased emotional, but not cognitive, empathy in response to both positive and negative valence stimuli. Interestingly, after OT treatment, emotional empathy responses in men were raised to levels similar to those found in untreated women. Two patients with selective bilateral damage to the amygdala (monozygotic twins with congenital Urbach–Wiethe disease) were impaired on both OT-sensitive aspects of these learning and empathy tasks, but performed normally on nonsocially reinforced learning and cognitive empathy. Overall these findings provide the first demonstration that OT can facilitate amygdala-dependent, socially reinforced learning and emotional empathy in men.

The brain's default mode, our ego, and Freud

Carhart-Harris and Friston offer an open access article exploring the notion that Freudian constructs may have neurobiological substrates.

Specifically, we propose that Freud’s descriptions of the primary and secondary processes are consistent with self-organized activity in hierarchical cortical systems and that his descriptions of the ego are consistent with the functions of the default-mode and its reciprocal exchanges with subordinate brain systems. This neurobiological account rests on a view of the brain as a hierarchical inference or Helmholtz machine. In this view, large-scale intrinsic networks occupy supraordinate levels of hierarchical brain systems that try to optimize their representation of the sensorium. This optimization has been formulated as minimizing a free-energy; a process that is formally similar to the treatment of energy in Freudian formulations. We substantiate this synthesis by showing that Freud’s descriptions of the primary process are consistent with the phenomenology and neurophysiology of rapid eye movement sleep, the early and acute psychotic state, the aura of temporal lobe epilepsy and hallucinogenic drug states.

The best illusion of the year contest

The top ten candidates for the 2010 best Illusion of the Year context have been chosen. The site show the illusions from previous years' competitions.

Doing two things at once splits the brain.

...and we are not very good at managing more than two things at once. Here is the fascinating abstract from Charron and Koechlin:

The anterior prefrontal cortex (APC) confers on humans the ability to simultaneously pursue several goals. How does the brain’s motivational system, including the medial frontal cortex (MFC), drive the pursuit of concurrent goals? Using brain imaging, we observed that the left and right MFC, which jointly drive single-task performance according to expected rewards, divide under dual-task conditions: While the left MFC encodes the rewards driving one task, the right MFC concurrently encodes those driving the other task. The same dichotomy was observed in the lateral frontal cortex, whereas the APC combined the rewards driving both tasks. The two frontal lobes thus divide for representing simultaneously two concurrent goals coordinated by the APC. The human frontal function seems limited to driving the pursuit of two concurrent goals simultaneously.

A figure from the ScienceNow review. When tackling tasks A and B simultaneously, half of the brain handles A (red) while the other handles B (yellow).