Homophobic? Maybe you're gay!

Two of the co-authors of an interesting article on homophobia in the Journal of Personality and Social Psychology summarize their work in a New York Times piece. They ask why political and religious figures who campaign against gay rights are so often implicated in sexual encounters with same-sex partners. Their:

... paper describes six studies conducted in the United States and Germany involving 784 university students. Participants rated their sexual orientation on a 10-point scale, ranging from gay to straight. Then they took a computer-administered test designed to measure their implicit sexual orientation. In the test, the participants were shown images and words indicative of hetero- and homosexuality (pictures of same-sex and straight couples, words like “homosexual” and “gay”) and were asked to sort them into the appropriate category, gay or straight, as quickly as possible. The computer measured their reaction times.

The twist was that before each word and image appeared, the word “me” or “other” was flashed on the screen for 35 milliseconds — long enough for participants to subliminally process the word but short enough that they could not consciously see it. The theory here, known as semantic association, is that when “me” precedes words or images that reflect your sexual orientation (for example, heterosexual images for a straight person), you will sort these images into the correct category faster than when “me” precedes words or images that are incongruent with your sexual orientation (for example, homosexual images for a straight person). This technique, adapted from similar tests used to assess attitudes like subconscious racial bias, reliably distinguishes between self-identified straight individuals and those who self-identify as lesbian, gay or bisexual. 

Over 20 percent of the participants who identified themselves as highly straight indicated some level of same-sex attraction (i.e., associated “me” most rapidly with gay-related words and pictures). These individuals were more likely than others to favor anti-gay policies, impose harsher penalties on petty crimes perpetrated by those thought to be gay, and were raised by parents perceived to be controlling, less accepting, and more prejudiced against homosexuals.

Structures of arousal and calm - This year's MindBlog Web Lecture

Having posted lectures that I have given for the past two years,  I thought I would pass on this year's talk. The topic of the talk derives from a scan of the  thousands of posts I have done since 2006 on Deric’s MindBlog. The scan for my favorites yielded groupings into areas that have I been most interested in, and suggested possible topics for a talk.  Some examples:

-Freud redux - The constancy of models of mind
-Can we cope with understanding out minds?
-Biology designs us for faith
-The 200 millisecond manager - it's all over in less   than a second.
-Are you breathing? - The evolution of arousal and calm
-What woke up this morning? And what can you do about it?
-The necessity of self delusion.

I decided to go with:

“Are you holding your breath?”  -  Structures of arousal and calm

You can find this talk via the MINDBLOG WEB LECTURES list in the column to your left, or HERE.

These take you to a Web techie toy (new to me) called Prezi, an idea and presentation manager.  Click on "More" in the bottom right corner of the window, go to full screen, and proceed through the presentation by clicking on the arrow at the bottom right of the screen. If you move the cursor to the left margin, zoom buttoms appear. Clicking on an area of the screen allows lets you move about on your own. Clicking on one of the URL links in the text opens that link in a new tab on your browser.  Press escape to look at that reference, then go back to the talk tab and resume the talk sequence.

From the first graphic in the presentation:

This is the web version of a talk given on Tuesday May 8, 2012, to the Tuesday noon Chaos and Complex Systems Seminar at the University of Wisconsin, Madison. It discusses some of the structures of calm and arousal - whether we are chilled out or losing it.   The material is cooked down to four sections that: (1), note some structures regulating calm and arousal  (2), list some brain and body correlates (3) consider the definition of the self that stresses or calms.  (4) discuss bottom-up and top-down regulators under some voluntary control that can alter the balance between calm and arousal. 

Analytic thinking promotes religious disbelief.

From Gervais and Norenzayan's introduction to their paper:

According to dual-process theories of human thinking, there are two distinct but interacting systems for information processing. One (System 1) relies upon frugal heuristics yielding intuitive responses, while the other (System 2) relies upon deliberative analytic processing. Although both systems can at times run in parallel, System 2 often overrides the input of system 1 when analytic tendencies are activated and cognitive resources are available. Dual-process theories have been successfully applied to diverse domains and phenomena across a wide range of fields

If religious belief emerges through a converging set of intuitive processes, and analytic processing can inhibit or override intuitive processing, then analytic thinking may undermine intuitive support for religious belief. Thus, a dual-process account predicts that analytic thinking may be one source of religious disbelief. Recent evidence is consistent with this hypothesis.

We adopted three complementary strategies to test for robustness and generality. First, study 1 tested whether individual differences in the tendency to engage analytic thinking are associated with reduced religious belief. Second, studies 2 to 5 established causation by testing whether various experimental manipulations of analytic processing, induced subtly and implicitly, encourage religious disbelief. These manipulations of analytic processing included visual priming, implicit priming, and cognitive disfluency. Third, across studies, we assessed religious belief using diverse measures that focused primarily on belief in and commitment to religiously endorsed supernatural agents. Samples consisted of participants from diverse cultural and religious backgrounds

From their abstract:

...Combined, these studies indicate that analytic processing is one factor (presumably among several) that promotes religious disbelief. Although these findings do not speak directly to conversations about the inherent rationality, value, or truth of religious beliefs, they illuminate one cognitive factor that may influence such discussions.

We don't project our visceral states onto dissimilar others.

Interesting observations from O’Brien and Ellsworth on limits to the empathy of our embodied cognition:

What people feel shapes their perceptions of others. We have examined the assimilative influence of visceral states on social judgment. Replicating prior research, we found in a first experiment that participants who were outside during winter overestimated the extent to which other people were bothered by cold, and in a second study found that participants who ate salty snacks without water thought other people were overly bothered by thirst. However, in both studies, this effect evaporated when participants believed that the other people under consideration held political views opposing their own. Participants who judged these dissimilar others were unaffected by their own strong visceral-drive states, a finding that highlights the power of dissimilarity in social judgment. Dissimilarity may thus represent a boundary condition for embodied cognition and inhibit an empathic understanding of shared out-group pain. Our findings reveal the need for a better understanding of how people’s internal experiences influence their perceptions of the feelings and experiences of those who may hold values different from their own.

Facial theory of politics

I wanted to pass on this piece by Leonard Mlodinow to continue the thread started in previous posts (also, click on 'faces' in the blog categories in the left column).  He points to work suggesting that voters, regardless of issues and ideology, unconsciously favor the candidate that seems to radiate competence and most 'looks the part.'

Better brains through exercise

Reynolds points to some fascinating work by Justin Rhodes that upends previous assumptions about the importance of a rich environment leading to increased brain power (in mice). Apparently physical exercise alone is the sine qua non. Rhodes:

...gathered four groups of mice and set them into four distinct living arrangements. One group lived in a world of sensual and gustatory plenty, dining on nuts, fruits and cheeses, their food occasionally dusted with cinnamon, all of it washed down with variously flavored waters. Their “beds” were colorful plastic igloos occupying one corner of the cage. Neon-hued balls, plastic tunnels, nibble-able blocks, mirrors and seesaws filled other parts of the cage. Group 2 had access to all of these pleasures, plus they had small disc-shaped running wheels in their cages. A third group’s cages held no embellishments, and they received standard, dull kibble. And the fourth group’s homes contained the running wheels but no other toys or treats. All the animals completed a series of cognitive tests at the start of the study and were injected with a substance that allows scientists to track changes in their brain structures. Then they ran, played or, if their environment was unenriched, lolled about in their cages for several months. Afterward, Rhodes’s team put the mice through the same cognitive tests and examined brain tissues. It turned out that the toys and tastes, no matter how stimulating, had not improved the animals’ brains...Animals that didn’t run, no matter how enriched their world was otherwise, did not improve their brainpower in complex, lasting ways...

Both human and animal studies have shown that exercise increases levels of brain-derived neurotropic factor, or B.D.N.F., that stimulates growth of the hippocampus as well as some other brain areas, and also improves performance on cognitive tests.

We're talking mice, not humans, and studies on human children and adults continue to suggest that mental exercises like the n-back test to enhance working memory that I've mentioned in several posts can increase fluid intelligence in a long term, but still reversible, way (use it or loose it.)

Walking on air.

I thought I would pass on this nifty video. Calming, but at the same time sobering to see how people are down there.

Physical exertion can impair recall and recognition.

Some interesting observations from Hope et al.:

Understanding memory performance under different operational conditions is critical in many occupational settings. To examine the effect of physical exertion on memory for a witnessed event, we placed two groups of law-enforcement officers in a live, occupationally relevant scenario. One group had previously completed a high-intensity physical-assault exercise, and the other had not. Participants who completed the assault exercise showed impaired recall and recognition performance compared with the control group. Specifically, they provided significantly less accurate information concerning critical and incidental target individuals encountered during the scenario, recalled less briefing information, and provided fewer briefing updates than control participants did. Exertion was also associated with reduced accuracy in identifying the critical target from a lineup. These results support arousal-based competition accounts proposing differential allocation of resources under physiological arousal. These novel findings relating to eyewitness memory performance have important implications for victims, ordinary citizens who become witnesses, and witnesses in policing, military, and related operational contexts.

Increases in stress and amygdala volume reversed by mindfulness meditation.

Davidson and McEwen offer a nice review of stress induced changes in the amygdala and hippocampus, and also describe experiments showing that mindfulness meditation can decrease both stress behavior and amygdala size. Here is their abstract, followed by two figures from the paper:

Experiential factors shape the neural circuits underlying social and emotional behavior from the prenatal period to the end of life. These factors include both incidental influences, such as early adversity, and intentional influences that can be produced in humans through specific interventions designed to promote prosocial behavior and well-being. Here we review important extant evidence in animal models and humans. Although the precise mechanisms of plasticity are still not fully understood, moderate to severe stress appears to increase the growth of several sectors of the amygdala, whereas the effects in the hippocampus and prefrontal cortex tend to be opposite. Structural and functional changes in the brain have been observed with cognitive therapy and certain forms of meditation and lead to the suggestion that well-being and other prosocial characteristics might be enhanced through training.

Figure - Chronic stress causes neurons to shrink or grow, but not necessarily to die. Representation of the chronic stress effects detected in animal models on growth or retraction of dendrites in the basolateral amygdala and orbitofrontal cortex (growth) and in the CA3 hippocampus, dentate gyrus and medial prefrontal cortex (shrinkage). These effects are largely reversible in young adult animals, although aging appears to compromise resilience and medial prefrontal cortex recovery.

Figure - Change in gray matter volume in the right basolateral amygdala from pre to post 8 weeks of mindfulness based stress reduction was associated with decreases in perceived stress over this same time period (see Hölzel et al.). Individuals undergoing MBSR who showed the largest decreases in perceived stress also showed the largest decreases in basolateral amygdala gray matter volume.

Both mental and physical effort rise from deep sub-cortical structures.

Schmidt et al. show that a common motivational system within the basala ganglia underlies performance of both mental and physical efforts.

Mental and physical efforts, such as paying attention and lifting weights, have been shown to involve different brain systems. These cognitive and motor systems, respectively, include cortical networks (prefronto-parietal and precentral regions) as well as subregions of the dorsal basal ganglia (caudate and putamen). Both systems appeared sensitive to incentive motivation: their activity increases when we work for higher rewards. Another brain system, including the ventral prefrontal cortex and the ventral basal ganglia, has been implicated in encoding expected rewards. How this motivational system drives the cognitive and motor systems remains poorly understood. More specifically, it is unclear whether cognitive and motor systems can be driven by a common motivational center or if they are driven by distinct, dedicated motivational modules. To address this issue, we used functional MRI to scan healthy participants while performing a task in which incentive motivation, cognitive, and motor demands were varied independently. We reasoned that a common motivational node should (1) represent the reward expected from effort exertion, (2) correlate with the performance attained, and (3) switch effective connectivity between cognitive and motor regions depending on task demand.

The ventral striatum fulfilled all three criteria and therefore qualified as a common motivational node capable of driving both cognitive and motor regions of the dorsal striatum. Thus, we suggest that the interaction between a common motivational system and the different task-specific systems underpinning behavioral performance might occur within the basal ganglia.

Liljeholm and O'Doherty also offer context and perspective on this work.

Young blood enhances repair of old brains.

In a Neuroscience perspective in Science Redmond and Chan summarize work of Ruckh et al. showing that factors present in the blood of younger mice (introduced by joining the circulatory systems of a young and old mouse) enhance repair of the myelin sheath around neuronal axons in the older mice. Here is a graphic from the summary:

Legend - The circulatory system of an “old” mouse (gray) with a demyelinated lesion was surgically joined with that of a healthy “young” mouse (white. The old mouse exhibited enhanced remyelination relative to the control, an old-old mouse pair. Remyelination depended on the recruitment of circulatory factors from the young mouse, including macrophages. Resident “old” oligodendroglia retain remyelination potential even as they age, but macrophage-mediated clearance of inhibitory myelin debris from the lesion may become impaired.

John Cleese on creativity

For the second time, I've come across some engaging comments by the British actor John Cleese, and I though I would pass them on. Cleese's model for creativity centers on the interplay of two modes of operating – open, where we take a wide-angle, abstract view of the problem and allow the mind to ponder possible solutions, and closed, where we zoom in on implementing a specific solution with narrow precision.  In the 10 minute video, he stresses the role of the unconscious. 

-Space ("You can't become playful, and therefore creative, if you're under your usual pressures.")

-Time ("It's not enough to create space; you have to create your space for a specific period of time.")


-Time ("Giving your mind as long as possible to come up with something original," and learning to tolerate the discomfort of pondering time and indecision.)

-Confidence ("Nothing will stop you being creative so effectively as the fear of making a mistake.")
 -Humor ("The main evolutionary significance of humor is that it gets us from the closed mode to the open mode quicker than anything else.")

Further points:

Creativity is not a talent. It is a way of operating.

We need to be in the open mode when pondering a problem – but! – once we come up with a solution, we must then switch to the closed mode to implement it. Because once we've made a decision, we are efficient only if we go through with it decisively, undistracted by doubts about its correctness.

To be at our most efficient, we need to be able to switch backwards and forward between the two modes. But – here's the problem – we too often get stuck in the closed mode. Under the pressures which are all too familiar to us, we tend to maintain tunnel vision at times when we really need to step back and contemplate the wider view. This is particularly true, for example, of politicians. The main complaint about them from their nonpolitical colleagues is that they've become so addicted to the adrenaline that they get from reacting to events on an hour-by-hour basis that they almost completely lose the desire or the ability to ponder problems in the open mode. Cleese concludes with a beautiful articulation of the premise and promise of his recipe for creativity:

This is the extraordinary thing about creativity: If just you keep your mind resting against the subject in a friendly but persistent way, sooner or later you will get a reward from your unconscious.

Swarm Intelligence - The Simpleton Ant and the Intelligent Ants

Another posting from my scan of responses to the edge.org annual question "What is your favorite deep elegant or beautiful explanation?" In his essay, Robert Sapolsky does a curious stroll through several candidate beautiful stories he considered (the double helix, the work of Hubel and Wiesel on how the visual brain extracts features, how the GI tract moves stuff along…) and comes to rest on this selection:

...emergence and complexity, as represented by "swarm intelligence."

Observe a single ant, and it doesn't make much sense, walking in one direction, suddenly careening in another for no obvious reason, doubling back on itself. Thoroughly unpredictable.

The same happens with two ants, a handful of ants. But a colony of ants makes fantastic sense. Specialized jobs, efficient means of exploiting new food sources, complex underground nests with temperature regulated within a few degrees. And critically, there's no blueprint or central source of command—each individual ants has algorithms for their behaviors. But this is not wisdom of the crowd, where a bunch of reasonably informed individuals outperform a single expert. The ants aren't reasonably informed about the big picture. Instead, the behavior algorithms of each ant consist of a few simple rules for interacting with the local environment and local ants. And out of this emerges a highly efficient colony.

Ant colonies excel at generating trails that connect locations in the shortest possible way, accomplished with simple rules about when to lay down a pheromone trail and what to do when encountering someone else's trail—approximations of optimal solutions to the Traveling Salesman problem. This has useful applications. In "ant-based routing," simulations using virtual ants with similar rules can generate optimal ways of connecting the nodes in a network, something of great interest to telecommunications companies. It applies to the developing brain, which must wire up vast numbers of neurons with vaster numbers of connections without constructing millions of miles of connecting axons. And migrating fetal neurons generate an efficient solution with a different version of ant-based routine.

A wonderful example is how local rules about attraction and repulsion (i.e., positive and negative charges) allow simple molecules in an organic soup to occasionally form more complex ones. Life may have originated this way without the requirement of bolts of lightening to catalyze the formation of complex molecules

. And why is self-organization so beautiful to my atheistic self? Because if complex, adaptive systems don't require a blue print, they don't require a blue print maker. If they don't require lightening bolts, they don't require Someone hurtling lightening bolts. 

Two different ways of making choices in two brain areas.

Kolling et al. note brain correlates of two different ways of making decisions. They use fMRI of humans to examine neural correlates of foraging, which involves a choice of whether or not to engage with options as they are encountered (which is different from the sort of binary choice between currently available options studied by behavioral economics.) Here is their abstract:

Behavioral economic studies involving limited numbers of choices have provided key insights into neural decision-making mechanisms. By contrast, animals’ foraging choices arise in the context of sequences of encounters with prey or food. On each encounter, the animal chooses whether to engage or, if the environment is sufficiently rich, to search elsewhere. The cost of foraging is also critical. We demonstrate that humans can alternate between two modes of choice, comparative decision-making and foraging, depending on distinct neural mechanisms in ventromedial prefrontal cortex (vmPFC) and anterior cingulate cortex (ACC) using distinct reference frames; in ACC, choice variables are represented in invariant reference to foraging or searching for alternatives. Whereas vmPFC encodes values of specific well-defined options, ACC encodes the average value of the foraging environment and cost of foraging.

More on why exercise is so good for us...

Many studies show that egular physical activity confers enormous fitness benefits. Exercise training enhances muscular endurance and strength, expends calories, and combats the development of common diseases such as obesity and type 2 diabetes. The effects of exercise are systemic and seemingly cannot be explained solely by the expenditure of calories in muscle.  Daniel Kelly writes a perspective on recent work showing how a new protein messenger named irisin (after Iris, the Greek messenger goddess) is released during muscle activity and triggers remodeling and energy expenditure in distant subcutaneous fat tissue deposits. Here is a summary figure of the muscle cell (myocyte) - fat cell (adipocyte) connection. 

Figure: The proposed irisin messenger system is depicted for humans [but was characterized in mice]. Exercise and energy expenditure induces the transcriptional regulator PGC-1α in the skeletal myocyte, which in turn drives the production of the membrane protein FNDC5. The circulating factor irisin, cleaved from FNDC5, activates thermogenic programs in white adipose tissue (“browning”), including mitochondrial biogenesis and the expression of uncoupling protein 1 (UCP1), leading to mitochondrial heat production and energy expenditure.

Seeing the whole reduces access to its parts.

The content of our conscious experience is automatically dictated by higher level stages of visual processing, which are associated with the representation of more abstract and meaningful interpretations. Poljac et. al. show that the ability to form a more abstract representation of a given visual input (in terms of a particular object) does not simply mean that the details of this stimulus are not immediately or automatically accessible to conscious perception, but that these details become fundamentally less accessible. The whole decreases access to the parts.

The experiments used computer generated walking dot figures of humans, both upright (easy to form the gestalt as human walking), and upside-down (more difficult to form the gestalt), as well as random stationary or moving dots. The rates of changes in dot colors were not perceived as well in the upright walking figures which generated the clearest gestalts.

They suggest that the rapid extraction of a perceptual Gestalt, and the inaccessibility of the parts that make up that Gestalt, may in fact reflect two sides of the same coin whereby human vision provides only the most useful level of abstraction to conscious awareness. This whole point is explained very beautifully in Metzinger's book, "The Ego Tunnel." (I did a series of five daily posts on this post, starting on 6/30/09)

Clothes can invade our body and brain...

Adam and Galinsky offer an interesting variant of studies on embodied cognition, a topic that MindBlog has frequently visited (35 postings, see left column) - showing that clothing can invade our body and brain, putting us into a different psychological state. After citing numerous studies of how clothes we wear have power over others, they do a discrete experiment to demonstrate a power of clothing over ourselves, specifically the power and accuracy of our attention:

We introduce the term “enclothed cognition” to describe the systematic influence that clothes have on the wearer's psychological processes. We offer a potentially unifying framework to integrate past findings and capture the diverse impact that clothes can have on the wearer by proposing that enclothed cognition involves the co-occurrence of two independent factors—the symbolic meaning of the clothes and the physical experience of wearing them. As a first test of our enclothed cognition perspective, the current research explored the effects of wearing a lab coat. A pretest found that a lab coat is generally associated with attentiveness and carefulness. We therefore predicted that wearing a lab coat would increase performance on attention-related tasks. In Experiment 1, physically wearing a lab coat increased selective attention compared to not wearing a lab coat. In Experiments 2 and 3, wearing a lab coat described as a doctor's coat increased sustained attention compared to wearing a lab coat described as a painter's coat, and compared to simply seeing or even identifying with a lab coat described as a doctor's coat. Thus, the current research suggests a basic principle of enclothed cognition—it depends on both the symbolic meaning and the physical experience of wearing the clothes.

When two heads are worse than one - the cost of collaboration

An interesting bit in Psychological Science from Minson and Mueller, who demonstrate that joint decision making exacerbates rejection of outside information and lowers accuracy of the effort:

Prior investigators have asserted that certain group characteristics cause group members to disregard outside information and that this behavior leads to diminished performance. We demonstrate that the very process of making a judgment collaboratively rather than individually also contributes to such myopic underweighting of external viewpoints. Dyad members exposed to numerical judgments made by peers gave significantly less weight to those judgments than did individuals working alone. This difference in willingness to use peer input was mediated by the greater confidence that the dyad members reported in the accuracy of their own estimates. Furthermore, dyads were no better at judging the relative accuracy of their own estimates and the advisor’s estimates than individuals were. Our analyses demonstrate that, relative to individuals, dyads suffered an accuracy cost. Specifically, if dyad members had given as much weight to peer input as individuals working alone did, then their revised estimates would have been significantly more accurate.

Why Curry, Wine And Coffee Cure Most Ails

A nice brief essay from Murali Doriaswamy:

What makes an explanation beautiful? Many elegant explanations in science are those that have been vetted fully but there are just as many beautiful wildly popular explanations where the beauty is just skin deep. I want to give two examples from the field of brain health.

When preliminary mice studies showed that an ingredient in dietary curry spice may have anti-Alzheimer effects, I suspect every vindaloo lover thought that was a beautiful explanation for why India had a low rate of Alzheimer's. But does India really have a low Alzheimer's rate after adjusting for life span and genetic differences? No one really knows..Likewise when an observational study in the 1990s reported wine drinkers in Bordeaux had lower rates of Alzheimer's, there was a collective "I knew it" from oenophiles...The latest observational findings now link coffee drinking with lower risk for Alzheimer's, much to the delight of the millions of caffeine addicts.

In reality, neither coffee nor wine nor curry spice have been proven in controlled trials to have any benefits against Alzheimer's. Regardless, the cognitive resonance these "remedies" find with the reader far exceeds the available evidence. One can find similar examples in virtually every field of medicine and science.

I would like to suggest two conditions that might render an explanation unusually beautiful: 1) a ring of truth, 2) confirmation biases. We all favor explanations and test them in a manner that confirms our own beliefs (confirmation bias). A small amount of factual data can be magnified into a beautiful fully proven explanation in one's mind if the right circumstance exist—thus, beauty is in the eye of the beholder. This may occur less often in one's own specialized fields, but we are all vulnerable in fields in which we are less expert in.

Given how often leading scientific explanations are proven wrong in subsequent years, one would do well to bear in mind Santayana's quote that "almost every wise saying has an opposite one, no less wise, to balance it". As for me, I love my curry, coffee and wine but am not yet counting on them to stop Alzheimer's.

How curriculum reform can decrease learning.

In the Editor's choice section of Science Magazine, McCartney reviews an interesting article in the Physics Education Journal:

Since 1975, the same Prior Knowledge Test (PKT) has been given to incoming students studying physics at the University of Bristol, UK. Designed to identify areas of math and physics that might need extra attention in the curriculum, PKT scores remained constant through 1991, decreased dramatically between 1992 and 2000, and stabilized after 2001, suggesting a clear change in the ability of students in the tested subjects. Barham argues that the decrease in scores was caused by modularization of the secondary education curriculum, which resulted in students learning the material required for each module examination and failing to retain it afterward. This highlights the dangers of a “learn and forget” approach to physics and math, and the author suggests that university faculty adapt their teaching methods to allow for the changes in preparedness of incoming students, particularly in math, where large parts of multistage calculations should not be skipped over. Furthermore, he argues for encouraging the understanding that physics and math are coherent disciplines, wherein material taught at all levels must be retained for a complete understanding of the subject.

Our brain structure changes after two hours of learning.

Sagi and colleagues have provided the first evidence that rapid structural plasticity can be detected in humans after just 2 hr of playing a video game. To assess brain structure they used diffusion magnetic resonance imaging, a technique sensitive to the self-diffusion of water molecules that depends on tissue architecture (how freely water diffuses depends on the space between the objects such as neurons, glia, and blood vessels, that it is moving through). They showd that only two hours of learning can cause a mean diffusivity reduction in the human hippocampus. In a similar supporting study on rats, the authors were able to show that changes in brain derived neurotropic growth (BDNF) factor correlated with the structural change measured by MRI. I'm passing on the abstract, and for those of you who like data, one of the figures from their paper.

The timescale of structural remodeling that accompanies functional neuroplasticity is largely unknown. Although structural remodeling of human brain tissue is known to occur following long-term (weeks) acquisition of a new skill, little is known as to what happens structurally when the brain needs to adopt new sequences of procedural rules or memorize a cascade of events within minutes or hours. Using diffusion tensor imaging (DTI), an MRI-based framework, we examined subjects before and after a spatial learning and memory task. Microstructural changes (as reflected by DTI measures) of limbic system structures (hippocampus and parahippocampus) were significant after only 2 hr of training. This observation was also found in a supporting rat study. We conclude that cellular rearrangement of neural tissue can be detected by DTI, and that this modality may allow neuroplasticity to be localized over short timescales.

Figure (Click on figure to enlarge it) - Structural Remodeling of Brain Tissue, Measured by DTI as Changes in MD after 2 hr of Training on a Spatial Learning and Memory TaskThe following statistical analyses were employed: paired t tests between the MD maps before and after the task in the learning group (A and F); planned comparisons analysis of the learning versus control groups with respect to scan time with predicated effect in the learning group only (B and G); and linear effect between groups (C and H) as well as a group by time interaction following ANOVA (D and I). The effects were found in the left hippocampus (A–D) and right parahippocampus (F–I). The parametric maps in these images were generated at a significance level of p less than 0.005 (uncorrected). The enlarged subset in those images indicates the significant voxels following correction for multiple comparisons (p less than 0.05, corrected). In the enlarged subset the corrected p value color scale is between 0.005 and 0.05. L indicates the left side of the brain. (E) and (J) show the MD values in the clusters in the subset of (A) and (F) (mean ± SEM). (K) shows the correlation analysis between subjects' improvement rates (see Figure 1) and decrease in MD in the right parahippocampus (of the cluster in F).

The happiest countries? I'm confused.

Having just done a post on March 2 on an article in the Economist reporting most happiness in poor and middle income countries (most Europeans less happy than rest of world), now appears a "World Happiness Report" (PDF here, Summary by lead author Helliwell here) prepared for a United Nations conference on happiness, that rates developed Northern European countries as having highest happiness. Compare the graphic below with the one in the March 2 post.  Helliwell: "the richest countries are a lot happier than the poorest."  The Economist: "the highest levels of self-reported happiness is not in rich countries."  I guess the way you ask the questions is rather crucial, and also sample size,  but at the moment I'm not patient enough to figure out what is going on.  Maybe a helpful reader will resolve all in a comment on this post.

Homophobic? Maybe you're Gay!

Two of the authors of an interesting study of homophobia summarize their article in the Journal of Personality and Social Psychology in a New York Times piece. They ask why political and religious figures who campaign against gay rights so often implicated in sexual encounters with same-sex partners and find solid evidence that homophobia can result from suppression of same-sex desires. Their:

...paper describes six studies conducted in the United States and Germany involving 784 university students. Participants rated their sexual orientation on a 10-point scale, ranging from gay to straight. Then they took a computer-administered test designed to measure their implicit sexual orientation. In the test, the participants were shown images and words indicative of hetero- and homosexuality (pictures of same-sex and straight couples, words like “homosexual” and “gay”) and were asked to sort them into the appropriate category, gay or straight, as quickly as possible. The computer measured their reaction times.

The twist was that before each word and image appeared, the word “me” or “other” was flashed on the screen for 35 milliseconds — long enough for participants to subliminally process the word but short enough that they could not consciously see it. The theory here, known as semantic association, is that when “me” precedes words or images that reflect your sexual orientation (for example, heterosexual images for a straight person), you will sort these images into the correct category faster than when “me” precedes words or images that are incongruent with your sexual orientation (for example, homosexual images for a straight person). This technique, adapted from similar tests used to assess attitudes like subconscious racial bias, reliably distinguishes between self-identified straight individuals and those who self-identify as lesbian, gay or bisexual. 

Individuals who self identified as highly straight but indicated some same sex attraction (i.e. 'me' with gay related words most rapidly) were more likely than other participants to favor anti-gay policies,  assign harsher punishments to petty crimes though to be perpetrated by gay people, and be raised by parents perceived to be controlling, less accepting and more prejudiced against homosexuals.

Colored brains carpet bomb the web.

I got very excited by two articles in the current issue of science, was about to do a long writeup,  and then realized such an effort would be incredibly redundant, because descriptions of the work were sprouting like mushrooms all over the blogosphere.   It reminds me of driving through small Texas towns with my grandmother when I was very young, and on asking "what do the people do here?" Her response: "They take in each other's laundry."

Anyway, Chen et al. do an analysis of the genetic topography of the cortex, and Wedeen et al. show fiber pathways in the brain. The studies find unifying hierarchical and geometric rules behind the organizational details that demonstrate overlapping grid structures. Here are just a few of the reviews, from Science, from Discover Magazine, from Time, from Medical News Today.

Innovation relies on the obscure.

McCaffrey suggests that a "generic-parts technique" enhances creative problem solving. He uses a toy insight problem - the two rings problem - as an example. The participant has to fasten together two weighty steel rings using only a long candle, a match, and a 2-in. cube of steel. Melted wax is not strong enough to bond the rings, so the solution relies on noticing that the wick is a string, which can be used to tie the rings together. Once people notice this, they easily devise a way to extricate the wick from the wax (e.g., scrape away the wax on the edge of the cube). Here is his abstract, followed by his description of the generic-parts technique:

A recent analysis of real-world problems that led to historic inventions and insight problems that are used in psychology experiments suggests that during innovative problem solving, individuals discover at least one infrequently noticed or new (i.e., obscure) feature of the problem that can be used to reach a solution. This observation suggests that research uncovering aspects of the human semantic, perceptual, and motor systems that inhibit the noticing of obscure features would enable researchers to identify effective techniques to overcome those obstacles. As a critical step in this research program, this study showed that the generic-parts technique can help people unearth the types of obscure features that can be used to overcome functional fixedness, which is a classic inhibitor to problem solving. Subjects trained on this technique solved on average 67% more problems than a control group did. By devising techniques that facilitate the noticing of obscure features in order to overcome impediments to problem solving (e.g., design fixation), researchers can systematically create a tool kit of innovation-enhancing techniques.

Here is his description of the generic parts technique (GPT)

...two questions are continually asked as a person creates a parts diagram (see figure below). For each description a participant creates, he or she should ask, “Can this be decomposed further?” If so, the participant should break that part into its subparts and create another hierarchy level in the diagram. The second question to ask is “Does this description imply a use?” If so, the participant should create a more generic description based on material and shape. This procedure results in a tree, in which the description in each leaf (i.e., the bottom level of the tree’s hierarchy) does not imply a use and involves the material and shape of the part under consideration. Further, because the parts become smaller as the hierarchy levels progress, this process also calls attention to the size of each of the parts. In essence, the GPT helps subjects think beyond the common functions associated with an object and its parts.

Feeling the moves - motor empathy with expert performance

Jola et al. make the interesting observation that experienced viewers of ballet, even without physical training, covertly simulate the movements for which they have acquired visual experience, their empathic abilities heighten motor resonance during dance observation - activating the same brain motor pathways actually being used by the dancers:

The human “mirror-system” is suggested to play a crucial role in action observation and execution, and is characterized by activity in the premotor and parietal cortices during the passive observation of movements. The previous motor experience of the observer has been shown to enhance the activity in this network. Yet visual experience could also have a determinant influence when watching more complex actions, as in dance performances. Here we tested the impact visual experience has on motor simulation when watching dance, by measuring changes in corticospinal excitability. We also tested the effects of empathic abilities. To fully match the participants' long-term visual experience with the present experimental setting, we used three live solo dance performances: ballet, Indian dance, and non-dance. Participants were either frequent dance spectators of ballet or Indian dance, or “novices” who never watched dance. None of the spectators had been physically trained in these dance styles. Transcranial magnetic stimulation was used to measure corticospinal excitability by means of motor-evoked potentials (MEPs) in both the hand and the arm, because the hand is specifically used in Indian dance and the arm is frequently engaged in ballet dance movements. We observed that frequent ballet spectators showed larger MEP amplitudes in the arm muscles when watching ballet compared to when they watched other performances. We also found that the higher Indian dance spectators scored on the fantasy subscale of the Interpersonal Reactivity Index, the larger their MEPs were in the arms when watching Indian dance. Our results show that even without physical training, corticospinal excitability can be enhanced as a function of either visual experience or the tendency to imaginatively transpose oneself into fictional characters. We suggest that spectators covertly simulate the movements for which they have acquired visual experience, and that empathic abilities heighten motor resonance during dance observation.

The Righteous Mind

I want to point to two reviews of Jonathan Haidt's new book, which has the title of this post. It brings exceptional clarity to the definition of contemporary liberals and conservatives, and argues that it is the liberals who are not getting the point. First, some clips from Kristof's comments:

Jonathan Haidt, a University of Virginia psychology professor, argues that, for liberals, morality is largely a matter of three values: caring for the weak, fairness and liberty. Conservatives share those concerns (although they think of fairness and liberty differently) and add three others: loyalty, respect for authority and sanctity...Those latter values bind groups together with a shared respect for symbols and institutions such as the flag or the military...This year’s Republican primaries have been a kaleidoscope of loyalty, authority and sanctity issues...Americans speak about values in six languages, from care to sanctity. Conservatives speak all six, but liberals are fluent in only three...Moral psychology can help to explain why the Democratic Party has had so much difficulty connecting with voters.

From Saletan's review:

Haidt argues that people are fundamentally intuitive, not rational. If you want to persuade others, you have to appeal to their sentiments...We were never designed to listen to reason. When you ask people moral questions, time their responses and scan their brains, their answers and brain activation patterns indicate that they reach conclusions quickly and produce reasons later only to justify what they’ve decided...The problem isn’t that people don’t reason. They do reason. But their arguments aim to support their conclusions, not yours. Reason doesn’t work like a judge or teacher, impartially weighing evidence or guiding us to wisdom. It works more like a lawyer or press secretary, justifying our acts and judgments to others...Haidt invokes an evolutionary hypothesis: We compete for social status, and the key advantage in this struggle is the ability to influence others. Reason, in this view, evolved to help us spin, not to help us learn. So if you want to change people’s minds, Haidt concludes, don’t appeal to their reason. Appeal to reason’s boss: the underlying moral intuitions whose conclusions reason defends.

We acquire morality the same way we acquire food preferences: we start with what we’re given. If it tastes good, we stick with it. If it doesn’t, we reject it. People accept God, authority and karma because these ideas suit their moral taste buds. Haidt points to research showing that people punish cheaters, accept many hierarchies and don’t support equal distribution of benefits when contributions are unequal...You don’t have to go abroad to see these ideas. You can find them in the Republican Party. Social conservatives see welfare and feminism as threats to responsibility and family stability. The Tea Party hates redistribution because it interferes with letting people reap what they earn. Faith, patriotism, valor, chastity, law and order — these Republican themes touch all six moral foundations, whereas Democrats, in Haidt’s analysis, focus almost entirely on care and fighting oppression. This is Haidt’s startling message to the left: When it comes to morality, conservatives are more broad-minded than liberals. They serve a more varied diet.

Is income inequality immoral? Should government favor religion? Can we tolerate cultures of female subjugation? And how far should we trust our instincts? Should people who find homosexuality repugnant overcome that reaction?..Haidt’s faith in moral taste receptors may not survive this scrutiny. Our taste for sanctity or authority, like our taste for sugar, could turn out to be a dangerous relic. But Haidt is right that we must learn what we have been, even if our nature is to transcend it.

Haidt's book references a number of experiments noted in MindBlog posts, on differences in the psychologies and autonomic nervous system reactivities of conservatives and liberals.

By the way, in this same vein, I might point to Chris Money's comments on his book "The Republican Brain," which he almost called "The Science of Truthiness," which asks why very intelligent Republicans deny scientific realities such as evolution and climate change.

Everything Is The Way It Is Because It Got That Way

An interesting summary of some core ideas in developmental psychology by Paul Bloom:

This aphorism is attributed to the biologist and classicist D'Arcy Thompson, and it's an elegant summary of how Thompson sought to explain the shapes of things, from jellyfish to sand dunes to elephant tusks....this insight applies to explanation more generally—all sciences are, to at least some extent, historical sciences. 

I think it's a perfect motto for my own field of developmental psychology. Every adult mind has two histories. There is evolution. Few would doubt that some of the most elegant and persuasive explanations in psychology appeal to the constructive process of natural selection. And there is development—how our minds unfold over time, the processes of maturation and learning. 

While evolutionary explanations work best for explaining what humans share, development can sometimes capture how we differ. This can be obvious: Nobody is surprised to hear that adults who are fluent in Korean have usually been exposed to Korean when they were children or that adults who practice Judaism have usually been raised as Jews. But other developmental explanations are rather interesting.

There is evidence that an adult's inability to see in stereo is due to poor vision during a critical period in childhood. Some have argued that the self-confidence of adult males is influenced by how young they were when they reached puberty (because of the boost in status caused by being bigger, even if temporarily, than their peers). It's been claimed that smarter adults are more likely to be firstborns (because later children find themselves in environments that are, on average, less intellectually sophisticated). Creative adults are more likely to be later-borns (because they were forced to find their own distinctive niches.) Romantic attachments in adults are influenced by their relationships as children with their parents. A man's pain-sensitivity later in life is influenced by whether or not he was circumcised as a baby.

With the exception of the stereo-vision example, I don't know if any of these explanations are true. But they are elegant and non-obvious, and some of them verge on beautiful.

Handedness affects the coding of affective information.

Interesting correlates from Brunyé et al.:

The body specificity hypothesis posits that the way in which people interact with the world affects their mental representation of information. For instance, right- versus left-handedness affects the mental representation of affective valence, with right-handers categorically associating good with rightward areas and bad with leftward areas, and left-handers doing the opposite. In two experiments we have tested whether this hypothesis can: extend to spatial memory, be measured in a continuous manner, be predicted by extent of handedness, and how the application of such a heuristic might vary as a function of informational specificity. A first experiment demonstrated systematic and continuous spatial location memory biases as a function of associated affective information; right-handed individuals misremembered positively- and negatively-valenced locations as further right and left, respectively, relative to their original locations. Left-handed individuals did the opposite, and in general those with stronger right- or left-handedness showed greater spatial memory biases. A second experiment tested whether participants would show similar effects when studying a map with high visual specificity (i.e., zoomed in); they did not. Overall we support the hypothesis that handedness affects the coding of affective information, and better specify the scope and nature of body-specific effects on spatial memory.

Emotion in Eastern and Western Music Mirrors Vocalization

Further interesting work from Purves and his colleagues:

In Western music, the major mode is typically used to convey excited, happy, bright or martial emotions, whereas the minor mode typically conveys subdued, sad or dark emotions. Recent studies indicate that the differences between these modes parallel differences between the prosodic and spectral characteristics of voiced speech sounds uttered in corresponding emotional states. Here we ask whether tonality and emotion are similarly linked in an Eastern musical tradition. The results show that the tonal relationships used to express positive/excited and negative/subdued emotions in classical South Indian music are much the same as those used in Western music. Moreover, tonal variations in the prosody of English and Tamil speech uttered in different emotional states are parallel to the tonal trends in music. These results are consistent with the hypothesis that the association between musical tonality and emotion is based on universal vocal characteristics of different affective states.

Eyes as location of the self.

Starmans and Bloom do an interesting nugget of work showing how children and adults see the eyes as the location of the self. In three experiments they:

...explore preschoolers’ and adults’ intuitions about the location of the self using a novel method that asks when an object is closet to a person. Children and adults judge objects near a person’s eyes to be closer to her than objects near other parts of her body. This holds even when considering an alien character whose eyes are located on its chest. Objects located near the eyes but out of sight are also judged to be close, suggesting that participants are not using what a person can see as a proxy for what is close to her. These findings suggest that children and adults intuitively think of the self as occupying a precise location within the body, at or near the eyes.

The importance of epigenetics in understanding nature/nurture interactions

I'm vaguely aware of the vast new field of epigenetics, defined in various ways, but all definitions are based in the central concept that environmental forces can affect gene behavior, either turning genes on or off. I thought this recent summary by Helen Fisher was a nice statement of the importance of this new field:

..two basic mechanisms are known: one involves molecules known as methyl-groups that latch on to DNA to suppress and silence gene expression; the other involves molecules known as acetyl-groups which activate and enhance gene expression...Moroccan Amazighs or Berbers, people with highly similar genetic profiles reside in three different environments: some roam the deserts as nomads; some farm the mountain slopes; some live in the towns and cities along the Moroccan coast. Depending on where they live, up to one-third of their genes are differentially expressed.

...Genes hold the instructions; epigenetic factors direct how those instructions are carried out. As we age, these epigenetic processes continue to modify and build who we are. Fifty-year-old twins, for example, show three times more epigenetic modifications than do three-year-old twins; and twins reared apart show more epigenetic alterations than those who grow up together. Genes are not destiny; but neither is the environment...some epigenetic instructions are passed from one generation to the next. Trans-generational epigenetic modifications are now documented in plants and fungi, and have been suggested in mice.

The 18^th century philosopher, John Locke, was convinced that the human mind is an empty slate upon which the environment inscribes personality. With equal self-assurance, others have been convinced that genes orchestrate our development, illnesses and life styles. Yet social scientists had failed for decades to explain the mechanisms governing behavioral variations between twins, family members and culture groups. And biological scientists had failed to pinpoint the genetic foundations of many mental illnesses and complex diseases. The central mechanism to explain these complex issues has been found...to me as an anthropologist long trying to take a middle road in a scientific discipline intractably immersed in nature-versus-nurture warfare, epigenetics is the missing link. 

Belief in and memory for an event can be independent constructs.

From Clark et al.:

Recent studies have shown that many people spontaneously report vivid memories of events that they do not believe to have occurred. In the present experiment we tested for the first time whether, after powerful false memories have been created, debriefing might leave behind nonbelieved memories for the fake events. In a first session participants imitated simple actions, and in Session two they saw doctored video-recordings containing clips that falsely suggested they had performed additional (fake) actions. As in earlier studies, this procedure created powerful false memories. Finally, participants were debriefed and told that specific actions in the video were not truly performed. Beliefs and memories for all critical actions were tested before and after the debriefing. Results showed that debriefing undermined participants' beliefs in fake actions, but left behind residual memory-like content. These results indicate that debriefing can leave behind vivid false memories which are no longer believed, and thus we demonstrate for the first time that the memory of an event can be experimentally dissociated from the belief in the event's occurrence. These results also confirm that belief in and memory for an event can be independently-occurring constructs.

Beyond mirror neurons - the neuroscience of real social encounters

A recent draft manuscript by Schilbach et al (PDF) has a nice summary of what a second-person neuroscience would be like, moving beyond spectator theories of knowledge:

Two neuroanatomically distinct large-scale networks have gained center stage as the neural substrates of social cognition: the so-called “mirror neuron system” and the “mentalizing network” . both of these paradigms are investigating actual, but limited domains of social cognition. Both are, in effect, committed to spectator theories of knowledge. They have focused on the use of isolation paradigms in which participants are required to merely observe others or think about their mental states rather than participate in social interaction with them. Consequently, it has remained unclear whether and how activity in the large-scale neural networks described above is modulated by the degree to which a person does or does not feel actively involved in an ongoing interaction and whether the networks might subserve complementary or mutually exclusive roles in this case

The article outlines work from his and other laboratories on brain imaging done during real time human interactions, noting in particular a ground-breaking study by Saito et al., who have devised a setup in which they not only use hyper-scanning, but also allow participants to interact in real-time by exchanging gaze behavior. Two MRI scanners were equipped with infrared eyetracking systems and video cameras. A live video image of the respective interaction partner’s face could be broadcast into the respective other scanner to generate a mediated face-to-face situation.

Here is the summary from Saito et al.:

Eye contact provides a communicative link between humans, prompting joint attention. As spontaneous brain activity might have an important role in the coordination of neuronal processing within the brain, their inter-subject synchronization might occur during eye contact. To test this, we conducted simultaneous functional MRI in pairs of adults. Eye contact was maintained at baseline while the subjects engaged in real-time gaze exchange in a joint attention task. Averted gaze activated the bilateral occipital pole extending to the right posterior superior temporal sulcus, the dorso-medial prefrontal cortex, and the bilateral inferior frontal gyrus. Following a partner’s gaze toward an object activated the left intraparietal sulcus. After all the task-related effects were modeled out, inter-individual correlation analysis of residual time-courses was performed. Paired subjects showed more prominent correlations than non-paired subjects in the right inferior frontal gyrus, suggesting that this region is involved in sharing intention during eye contact that provides the context for joint attention.

Our brains lengthen perceptions of biological motions.

Wang and Jiang show that the inherent temporal properties of life motion signals spontaneously engage more intricate brain processings compared with those of nonbiological motions, and consequentially induce subjective time dilation. They thus suggest that the temporal encoding of biological motions relies upon a specialized brain mechanism intrinsically tuned to life motion signals irrespective of their configurations, and is essentially an automatic process operating without a person's awareness.

Point-light biological motions, conveying various different attributes of biological entities, have particular spatiotemporal properties that enable them to be processed with remarkable efficiency in the human visual system. Here we demonstrate that such signals automatically lengthen their perceived temporal duration independent of global configuration and without observers’ subjective awareness of their biological nature. By using a duration discrimination paradigm, we showed that an upright biological motion sequence was perceived significantly longer than an inverted but otherwise identical sequence of the same duration. Furthermore, this temporal dilation effect could be extended to spatially scrambled biological motion signals, whose global configurations were completely disrupted, regardless of whether observers were aware of the nature of the stimuli. However, such an effect completely disappeared when critical biological characteristics were removed. Taken together, our findings suggest a special mechanism of time perception tuned to life motion signals and shed new light on the temporal encoding of biological motion.

Meditation practice increases brain size and gyrification

Luders and her colleagues (PDF here) have examined 44 people — 22 control subjects and 22 who had practiced various forms of meditation, including Zazen, Samatha and Vipassana, among others. The amount of time they had practiced ranged from five to 46 years, with an average of 24 years. More than half of all the meditators said that deep concentration was an essential part of their practice, and most meditated between 10 and 90 minutes every day. The MRI measurements found significantly larger cerebral measurements in meditators compared with controls: larger volumes of the right hippocampus and increased gray matter in the right orbito-frontal cortex, the right thalamus and the left inferior temporal lobe. Increases in the left and right anterior dorsal insula - which is a hub for internal autonomic, affective, and cognitive integration - were most pronounced. There were no regions where controls had significantly larger volumes or more gray matter than meditators. The enlarged brain areas are linked to emotions, making one wonder whether this reflects the increased 'emotional muscles' of meditators,i.e. their ability to regulate their emotions.

 Cortical Surface Shown is the lateral view of the right cortical surface. The red circle indicates where the maximum effect occurred. Top: Larger gyrification in 50 long-term meditators compared to 50 well-matched controls. Bottom: Positive correlations between gyrification and the number of meditation years within the 50 meditators. (Credit: Image courtesy of University of California - Los Angeles)

Serotonin and reaction to unfairness.

How should one deal with line cutters? Or, more generally, what would you do if you faced unfair or wrong behavior? Studies have shown that machiavellian individuals accept unfair offers more often in ultimatum games (UG), using realism and opportunism to maximize their self-interest. 5-HT (serotonin) transmission, for which the dorsal raphe nucleus (DRN) is a major source, is important in brain regions such as the dorsal lateral prefrontal cortex that are recruited for this kind of cognitive control. Honest and trustful persons who cannot easily separate themselves from moral precepts tend to adhere to a norm of fairness and thus show lower tolerance of unfairness. Takahashi et al. have now used positron emission tomography to directly measure 5-HT transporters (5-HTT) and 5-HT1A receptors and find that low 5-HTT in the DRN is associated with straightforwardness and trust personality traits and predicts higher rejection rates of unfair offers in the ultimatum game. Here is their abstract:

How does one deal with unfair behaviors? This subject has long been investigated by various disciplines including philosophy, psychology, economics, and biology. However, our reactions to unfairness differ from one individual to another. Experimental economics studies using the ultimatum game (UG), in which players must decide whether to accept or reject fair or unfair offers, have also shown that there are substantial individual differences in reaction to unfairness. However, little is known about psychological as well as neurobiological mechanisms of this observation. We combined a molecular imaging technique, an economics game, and a personality inventory to elucidate the neurobiological mechanism of heterogeneous reactions to unfairness. Contrary to the common belief that aggressive personalities (impulsivity or hostility) are related to the high rejection rate of unfair offers in UG, we found that individuals with apparently peaceful personalities (straightforwardness and trust) rejected more often and were engaged in personally costly forms of retaliation. Furthermore, individuals with a low level of serotonin transporters in the dorsal raphe nucleus (DRN) are honest and trustful, and thus cannot tolerate unfairness, being candid in expressing their frustrations. In other words, higher central serotonin transmission might allow us to behave adroitly and opportunistically, being good at playing games while pursuing self-interest. We provide unique neurobiological evidence to account for individual differences of reaction to unfairness.

Correlation between rejection rate of unfair offers in UG and 5-HTT binding in DRN. (A) SPM image showing regions of negative correlation between rejection rate of unfair offers and 5-HTT binding in DRN. (B) Plots and regression line of correlation between rejection rate of unfair offers and 5-HTT binding in DRN (R = −0.50, P = 0.026). Dashed lines are 95% confidence interval boundaries.

Elegance of our brain lies in its inelegance.

I want to pass on this nice brief essay by David Eagleman:

For centuries, neuroscience attempted to neatly assign labels to the various parts of the brain: this is the area for language, this one for morality, this for tool use, color detection, face recognition, and so on. This search for an orderly brain map started off as a viable endeavor, but turned out to be misguided.

The deep and beautiful trick of the brain is more interesting: it possesses multiple, overlapping ways of dealing with the world. It is a machine built of conflicting parts. It is a representative democracy that functions by competition among parties who all believe they know the right way to solve the problem.

As a result, we can get mad at ourselves, argue with ourselves, curse at ourselves and contract with ourselves. We can feel conflicted. These sorts of neural battles lie behind marital infidelity, relapses into addiction, cheating on diets, breaking of New Year's resolutions—all situations in which some parts of a person want one thing and other parts another.

These are things which modern machines simply do not do. Your car cannot be conflicted about which way to turn: it has one steering wheel commanded by only one driver, and it follows directions without complaint. Brains, on the other hand, can be of two minds, and often many more. We don't know whether to turn toward the cake or away from it, because there are several sets of hands on the steering wheel of behavior.

Take memory. Under normal circumstances, memories of daily events are consolidated by an area of the brain called the hippocampus. But in frightening situations—such as a car accident or a robbery—another area, the amygdala, also lays down memories along an independent, secondary memory track. Amygdala memories have a different quality to them: they are difficult to erase and they can return in "flash-bulb" fashion—a common description of rape victims and war veterans. In other words, there is more than one way to lay down memory. We're not talking about memories of different events, but different memories of the same event. The unfolding story appears to be that there may be even more than two factions involved, all writing down information and later competing to tell the story. The unity of memory is an illusion.

And consider the different systems involved in decision making: some are fast, automatic and below the surface of conscious awareness; others are slow, cognitive, and conscious. And there's no reason to assume there are only two systems; there may well be a spectrum. Some networks in the brain are implicated in long-term decisions, others in short-term impulses (and there may be a fleet of medium-term biases as well).

Attention, also, has also recently come to be understood as the end result of multiple, competing networks, some for focused, dedicated attention to a specific task, and others for monitoring broadly (vigilance). They are always locked in competition to steer the actions of the organism.

Even basic sensory functions—like the detection of motion—appear now to have been reinvented multiple times by evolution. This provides the perfect substrate for a neural democracy.

On a larger anatomical scale, the two hemispheres of the brain, left and right, can be understood as overlapping systems that compete. We know this from patients whose hemispheres are disconnected: they essentially function with two independent brains. For example, put a pencil in each hand, and they can simultaneously draw incompatible figures such as a circle and a triangle. The two hemispheres function differently in the domains of language, abstract thinking, story construction, inference, memory, gambling strategies, and so on. The two halves constitute a team of rivals: agents with the same goals but slightly different ways of going about it.

To my mind, this elegant solution to the mysteries of the brain should change the goal for aspiring neuroscientists. Instead of spending years advocating for one's favorite solution, the mission should evolve into elucidating the different overlapping solutions: how they compete, how the union is held together, and what happens when things fall apart.
Part of the importance of discovering elegant solutions is capitalizing on them. The neural democracy model may be just the thing to dislodge artificial intelligence. We human programmers still approach a problem by assuming there's a best way to solve it, or that there's a way it should be solved. But evolution does not solve a problem and then check it off the list. Instead, it ceaselessly reinvents programs, each with overlapping and competing approaches. The lesson is to abandon the question "what's the most clever way to solve that problem?" in favor of "are there multiple, overlapping ways to solve that problem?" This will be the starting point in ushering in a fruitful new age of elegantly inelegant computational devices.

Cognitive enhancement is in our futures.

I want to point to three articles on brain enhancement that have accumulated in my queue of potential items for posting:

Benedict Carey discusses work showing that deep brain stimulation delivered through electrodes inserted into the brains of epilepsy patients being prepared for surgery sharply improved performance on a virtual driving game that tests spatial memory, the neural mapping ability that allows people to navigate a new city without a GPS:

Ross Andersen does an article in The Atlantic that describes ethical debates that have risen over the use of transcranial direct current stimulation (TDCS) to improve cognition in human beings.

Recent years have seen some encouraging, if preliminary, lab results involving TDCS, a deep brain stimulation technique that uses electrodes placed outside the head to direct tiny painless currents across the brain. The currents are thought to increase neuroplasticity, making it easier for neurons to fire and form the connections that enable learning. There are signs that the technology could improve language acumen, math ability, and even memory.

Finally in PloS Biology Knafo et al. note that a pharmacological cognitive enhancer that improves spatial learning and memory (in rats) by enhancing synaptic transmission in the hippocampus.

The debate over the evolution of altruism.

Jonah Lehrer does a fascinating article in the March 5 issue of The New Yorker titled "Kind and Kind - a fight about the genetics of altruism". He gives the history of that debate starting by describing the work of William Hamilton and his successors, but centers on the contributions of E.O. Wilson. The last few paragraphs of Lehrer's article, which outline Wilson's current views, are a nice summary that I want to pass on here:

Wilson's current explanation for altruism has returned to a hypothesis first proposed by Darwin.. that human generosity might have evolved as an emergent property not of the individual but of the group…While acts of altruism can be costly for the individual, Darwin argued that they helped sustain the colony, which made individuals within the colony more likely to survive.

The idea is know as group selection, and it's an explanation that most evolutionary biologists now dismiss [inserted note: with the exception of David Sloan Wilson, not mentioned by Lehrer, but whose work is referenced in about 6 mindblog posts.], because the advantages of generosity are much less tangible than the benefits of selfishness. A tribe full of nice guys would be easy prey for a cheater, who would quickly spread his genes through the population. But Wilson believes that it may hold the key to understanding altruism. To make his case, he cites recent studies of "cooperating" microbes, plants, and even female lions. In all these studies, many of which have been conducted in the controlled conditions of the lab, clumps of cooperators thrive and replicate, while selfish groups wither and die. In a 2007 paper that he co-authored, he summarizes his new view in three terse sentences: "selfishness beats altruism within groups. Altruistic groups beat selfish groups. Everything else is commentary."

Wilson's larger point is that, to the extent that altruism exists, is isn't an illusion. Instead, goodness might actually be an adaptive trait, allowing more cooperative groups to outcompete their conniving cousins. In a field defined by the cruel logic of natural selection, group selection appears to be the rare hint of virtue, the one biological force pushing back against the obvious advantages of greed and deceit. "I see human nature as hung in the balance between these two extremes," Wilson says. "If our behavior was driven entirely by group selection, then we'd be robotic cooperators, like ants. But, if individual-level selection was the only thing that mattered, then we'd be entirely selfish. What makes us human is that our history has been shaped by both forces. We're stuck in between."

Why humans made it, and chimps didn’t

Fascinating work on the comparative cognitive and social behavior of humans and chimpanzees continues to pour out, highlighting behaviors that made us human. Yamamoto et al. show that Chimpanzees can understand conspecifics’ goals and demonstrate cognitively advanced targeted helping as long as they are able to visually evaluate their conspecifics’ predicament. However, they will seldom help others without direct request for help. And, Dean et al. compare higher-level problem solving behaviors in Capuchin Monkeys, Chimpanzees, and human infants, finding that a package of sociocognitive processes are found only in humans:

The remarkable ecological and demographic success of humanity is largely attributed to our capacity for cumulative culture, with knowledge and technology accumulating over time, yet the social and cognitive capabilities that have enabled cumulative culture remain unclear. In a comparative study of sequential problem solving, we provided groups of capuchin monkeys, chimpanzees, and children with an experimental puzzlebox that could be solved in three stages to retrieve rewards of increasing desirability. The success of the children, but not of the chimpanzees or capuchins, in reaching higher-level solutions was strongly associated with a package of sociocognitive processes—including teaching through verbal instruction, imitation, and prosociality—that were observed only in the children and covaried with performance.

Recurring patterns in music from Bach to Scott Joplin

More amazing stuff from Daniel Levitan on music...first an except from the introduction to his latest paper in PNAS:

Musical behaviors—singing, dancing, and playing instruments—date back to Neanderthals, and have been a part of every human culture as far back as we know. People experience great enjoyment and pleasure from music, and music theorists have argued that this enjoyment stems in part from the structural features of music, such as the generation and violation of expectations... Mathematics has often been used to characterize, model, and understand music, from Schenkerian analysis to neural topography; and geometric models of tonality. One particular mathematical relation that has received attention in music is the 1/f distribution, which Mandelbrot termed “fractal.” 1/f distributions have been found to be a key feature of a number of natural and sensory phenomena. Analyzing the frequency of several natural disasters, including earthquakes, landslides, floods, and terrestrial meteor impacts,  reveals an inverse log-log linear (fractal) relation between the frequency and the intensity of the events.

Here is the abstract:

Much of our enjoyment of music comes from its balance of predictability and surprise. Musical pitch fluctuations follow a 1/f power law that precisely achieves this balance. Musical rhythms, especially those of Western classical music, are considered highly regular and predictable, and this predictability has been hypothesized to underlie rhythm's contribution to our enjoyment of music. Are musical rhythms indeed entirely predictable and how do they vary with genre and composer? To answer this question, we analyzed the rhythm spectra of 1,788 movements from 558 compositions of Western classical music. We found that an overwhelming majority of rhythms obeyed a 1/f^β power law across 16 subgenres and 40 composers, with β ranging from ∼0.5–1. Notably, classical composers, whose compositions are known to exhibit nearly identical 1/f pitch spectra, demonstrated distinctive 1/f rhythm spectra: Beethoven's rhythms were among the most predictable, and Mozart's among the least. Our finding of the ubiquity of 1/f rhythm spectra in compositions spanning nearly four centuries demonstrates that, as with musical pitch, musical rhythms also exhibit a balance of predictability and surprise that could contribute in a fundamental way to our aesthetic experience of music. Although music compositions are intended to be performed, the fact that the notated rhythms follow a 1/f spectrum indicates that such structure is no mere artifact of performance or perception, but rather, exists within the written composition before the music is performed. Furthermore, composers systematically manipulate (consciously or otherwise) the predictability in 1/f rhythms to give their compositions unique identities. 

The rich behaving badly

No big surprise, I guess, but here is a gem from Piff et al. that shows in a variety of different experimental settings that higher social class predicts increased unethical behavior. The authors agree with Plato and Aristotle, who deemed greed to be at the root of personal immorality.

Seven studies using experimental and naturalistic methods reveal that upper-class individuals behave more unethically than lower-class individuals. In studies 1 and 2, upper-class individuals were more likely to break the law while driving, relative to lower-class individuals. In follow-up laboratory studies, upper-class individuals were more likely to exhibit unethical decision-making tendencies (study 3), take valued goods from others (study 4), lie in a negotiation (study 5), cheat to increase their chances of winning a prize (study 6), and endorse unethical behavior at work (study 7) than were lower-class individuals. Mediator and moderator data demonstrated that upper-class individuals’ unethical tendencies are accounted for, in part, by their more favorable attitudes toward greed.

Some details on the first four studies: Studies 1 and 2 were naturalistic field studies that used observers’ codes of vehicle status (make, age, and appearance,known to be reliable indicators of a person’s social rank and wealth) to index drivers’ social class. Observers stood near the intersection, coded the status of approaching vehicles, and recorded whether the driver cut off other vehicles by crossing the intersection before waiting their turn, a behavior that defies the California Vehicle Code. In study 3 participants who reported their social class using the MacArthur scale of subjective socioeconomic status read eight different scenarios that implicated an actor in unrightfully taking or benefiting from something, and reported the likelihood that they would engage in the behavior described. In study 4 participants were primed to activate higher or lower social-class mindsets. The experimenter then presented participants with a jar of individually wrapped candies, ostensibly for children in a nearby laboratory, but informed them that they could take some if they wanted. This task was adapted from prior research on entitlement, and served as our measure of unethical behavior because taking candy would reduce the amount that would otherwise be given to children. Participants completed unrelated tasks and then reported the number of candies they had taken.

Our brain connectivity predicts perceptual task performance.

An MRI scan may soon be part of the interview process for jobs requiring skill at learning and performing novel tasks...Baldassarre et al. do fMRI measurements showing that certain patterns of resting state functional connectivity within visual cortex, and between visual cortex and higher-order cortical regions - before exposure to a novel perceptual task - represent neural predictors of individual differences in performing that task. Further, the topography of the prior connectivity coincides with the areas subsequently recruited by task performance. Here is their abstract:

People differ in their ability to perform novel perceptual tasks, both during initial exposure and in the rate of improvement with practice. It is also known that regions of the brain recruited by particular tasks change their activity during learning. Here we investigate neural signals predictive of individual variability in performance. We used resting-state functional MRI to assess functional connectivity before training on a novel visual discrimination task. Subsequent task performance was related to functional connectivity measures within portions of visual cortex and between visual cortex and prefrontal association areas. Our results indicate that individual differences in performing novel perceptual tasks can be related to individual differences in spontaneous cortical activity.

Childhood maltreatment reduces brain volume.

Shortly after putting up this post on maternal nurturing correlating with larger hippocampal volumes, I can across the flip side of the story from Teicher et al. Comparing 193 subjects of average age 22 who showed high vs. low scores on the Childhood Trauma Questionnaire and Adverse Childhood Experience study showed volume reductions in several areas of the hippocampus:

Childhood maltreatment or abuse is a major risk factor for mood, anxiety, substance abuse, psychotic, and personality disorders, and it is associated with reduced adult hippocampal volume, particularly on the left side. Translational studies show that the key consequences of stress exposure on the hippocampus are suppression of neurogenesis in the dentate gyrus (DG) and dendritic remodeling in the cornu ammonis (CA), particularly the CA3 subfield... The sample consisted of 193 unmedicated right-handed subjects (38% male, 21.9 ± 2.1 y of age) selected from the community. Maltreatment was quantified using the Adverse Childhood Experience study and Childhood Trauma Questionnaire scores. The strongest associations between maltreatment and volume were observed in the left CA2-CA3 and CA4-DG subfields, and were not mediated by histories of major depression or posttraumatic stress disorder. Comparing subjects with high vs. low scores on the Childhood Trauma Questionnaire and Adverse Childhood Experience study showed an average volume reduction of 6.3% and 6.1% in the left CA2-CA3 and CA4-DG, respectively. Volume reductions in the CA1 and fimbria were 44% and 60% smaller than in the CA2-CA3. Interestingly, maltreatment was associated with 4.2% and 4.3% reductions in the left presubiculum and subiculum, respectively. These findings support the hypothesis that exposure to early stress in humans, as in other animals, affects hippocampal subfield development.

Added note: Relevant to the subject of this post, I just got an email from a children's metal health advocacy group, The Child Mind Institute, that is sponsoring an annual public education campaign called "Speak Up For Kids".