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.