Friday, June 22, 2012

How depressives surf the web.

A brief piece with the title of this post recently appeared in the NYTimes, and is an example of annoying phenomenon: advertising by advance announcement in popular media with reference made to a "forthcoming" article. The points raised are interesting enough that the reader deserves access to what might be more thorough analysis and discussion. I'm thinking the correlations indicated might be quite spurious. For what it is worth, in a study involving the usual gaggle of undergraduate volunteers, the authors claim to have:
...identified several features of Internet usage that correlated with depression. In other words, we found a trend: in general, the more a participant’s score on the survey indicated depression, the more his or her Internet usage included these (rather technical-sounding) features — for instance, “p2p packets,” which indicate high levels of sharing files (like movies and music).
Our second major discovery was that there were patterns of Internet usage that were statistically high among participants with depressive symptoms compared with those without symptoms. That is, we found indicators: styles of Internet behavior that were signs of depressive people. For example, participants with depressive symptoms tended to engage in very high e-mail usage. This perhaps was to be expected: research by the psychologists Janet Morahan-Martin and Phyllis Schumacher has shown that frequent checking of e-mail may relate to high levels of anxiety, which itself correlates with depressive symptoms.
Another example: the Internet usage of depressive people tended to exhibit high “flow duration entropy” — which often occurs when there is frequent switching among Internet applications like e-mail, chat rooms and games. This may indicate difficulty concentrating. This finding, too, is consistent with the psychological literature: according to the National Institute of Mental Health, difficulty concentrating is also a sign of depressive symptoms among students... OTHER characteristic features of “depressive” Internet behavior included increased amounts of video watching, gaming and chatting.

Thursday, June 21, 2012

Highjacked brain fallacy, and free will illusion going mainstream.

In a series of previous posts on MindBlog I have enjoyed following the continuing back and forth over free will and neuroscience,and my own sentiments are clearly revealed in my introductory web/lecture listed in the column to your left ("The I Illusion"). A raft of books on this subject has recently appeared, an example being Eagleman's "Incognito: Secret Lives of the Brain" as well as several mentioned in a recent Huffington Post essay by Victor Strenger. An interesting variation on the free will question is provided by O'Connor's discussion of a popular analogy that clouds our discussion of addiction, i.e. the portrayal of addition as a disease (not subject to our willful control, thus not the responsibility of the victim) rather than a choice.
In the “hijacked” view of addiction, the brain is the innocent victim of certain substances — alcohol, cocaine, nicotine or heroin, for example — as well as certain behaviors like eating, gambling or sexual activity...drugs like alcohol and cocaine and behaviors like gambling light up the brain’s pleasure circuitry, often bringing a burst of euphoria. Other studies indicate that people who are addicted have lower dopamine and serotonin levels in their brains, which means that it takes more of a particular substance or behavior for them to experience pleasure or to reach a certain threshold of pleasure.
However,
"A hijacker comes from outside and takes control by violent means. A hijacker takes a vehicle that is not his; hijacking is always a form of stealing and kidnapping...The analogy of addiction and hijacking involves the same category mistake as the money switched from hand to hand...It might be tempting to claim that in an addiction scenario, the drugs or behaviors are the hijackers. However, those drugs and behaviors need to be done by the person herself...In the usual cases, an individual is the one putting chemicals into her body or engaging in certain behaviors in the hopes of getting high...There is a kind of intentionality to hijacking that clearly is absent in addiction...Addiction develops over time and requires repeated and worsening use...If we think, however, of addiction as involving both choice and disease, our outlook is likely to become more nuanced.
Linking choice and responsibility is right in many ways, so long as we acknowledge that choice can be constrained in ways other than by force or overt coercion. There is no doubt that the choices of people progressing to addiction are constrained; compulsion and impulsiveness constrain choices. Many addicts will say that they choose to take that first drink or drug and that once they start they cannot stop. A classic binge drinker is a prime example; his choices are constrained with the first drink. He both has and does not have a choice. (That moment before the first drink or drug is what the philosopher Owen Flanagan describes as a “zone of control.”) But he still bears some degree of responsibility to others and to himself...Addicts are neither hijackers nor victims. It is time to retire this analogy.

Wednesday, June 20, 2012

Exercise bad for you?

My almost religious devotion to exercise has been slightly nudged by this piece by Gina Kolata pointing to a study by Bouchard et al., who do a rather thorough exercise study involving 1,687 people to find that
...about 10 percent actually got worse on at least one of the measures related to heart disease: blood pressure and levels of insulin, HDL cholesterol or triglycerides....But counterbalancing the 10 percent who got worse were about the same proportion who had an exaggeratedly good response on at least one measure. Others had responses ranging from little or no change up to big changes, seen in about 10 percent, where risk factor measurements improved anywhere from 20 percent to 50 percent.

Tuesday, June 19, 2012

The burdens of being a biped

Given my current preoccupation with my failing 70 year old knee joints, I was drawn to a brief piece by Elizabeth Pennisi with the title of this post.  Here I give a summary graphic and a few clips of her discussion:


...a number of musculoskeletal issues are traceable to our past, in particular to the switch to walking upright more than 7 million years ago…Shifting from a four-legged support system to a two-legged one put extra stress on the legs and vertebrae. Adaptations in the feet, knees, hips, pelvis, and spine accommodate these forces, but at a cost…vertebrae that break more easily, weaker bones, and feet prone to heel spurs and sprained ankles…A brief tour of the body reveals a number of design flaws, the legacy of our past…

Spine. Back pain is the leading health complaint in the United States. In dogs, horses, and even chimpanzees, the backbone is a series of vertebrae neatly stacked and evenly spaced to form a relatively stiff, gently curving beam…the human spine… is highly flexible and can even bend backward..this flexibility creates wear and tear on joint surfaces and predisposes us to osteoarthritis…One type of break, called spondylolysis, affects about 6% of the U.S. population and is a leading cause of lower-back pain in teenage athletes. In this condition, the neural arch - a triangle of bone that surrounds the spinal cord - detaches from the rest of its vertebra, allowing the spine to slip forward relative to the back of the pelvis, pinching nerves and causing pain…the problem lies in inadequate spacing between the joints connecting the vertebrae.

Feet. To cope with the added load on just two feet, the foot evolved a shock-absorbing arch by bringing what was a grasping big toe into line with the other toes. When that arch fails to form fully, as in people with flat feet, fatigue fractures can result.

Fragile bones. The added load on two feet also caused knee and hip joints to expand, creating more surface area to absorb foot-fall forces. But the joints—and vertebrae as well—evolved to be bigger by enlarging the spongy, inner bone and thinning the hard, outer bone. As a result, human bones are less dense than those of other primates. Bone...loses mass during adulthood. With humans having ever longer life spans, bones, particularly vertebrae, may become fragile and break spontaneously.

Bipedality leaves its mark in other parts of our bodies, too, for example in the difficulty of childbirth and in our vulnerability to rotator cuff injuries of the shoulder. loses mass during adulthood. With humans having ever longer life spans, bones, particularly vertebrae, may become fragile and break spontaneously.

Monday, June 18, 2012

A musical offering.

As has been my custom, I post on this blog piano video-recordings that I have recently made, this being the Chopin Nocturne in C# Minor that I played at a house concert on May 27, and subsequently recorded on June 10.

Friday, June 15, 2012

Skin Pics

One frequently comes across amazing images in cell biology. This time I felt like passing some on to readers.

Thursday, June 14, 2012

The science of gaydar

Yet another study suggesting that we have an ability (if not a proficiency) to correctly judge the sexual orientation of others about 60% of the time, significantly great than chance. This piece in the New York Times points to work by Tabak and Zayas:
Research has shown that people are able to judge sexual orientation from faces with above-chance accuracy, but little is known about how these judgments are formed. Here, we investigated the importance of well-established face processing mechanisms in such judgments: featural processing (e.g., an eye) and configural processing (e.g., spatial distance between eyes). Participants judged sexual orientation from faces presented for 50 milliseconds either upright, which recruits both configural and featural processing, or upside-down, when configural processing is strongly impaired and featural processing remains relatively intact. Although participants judged women’s and men’s sexual orientation with above-chance accuracy for upright faces and for upside-down faces, accuracy for upside-down faces was significantly reduced. The reduced judgment accuracy for upside-down faces indicates that configural face processing significantly contributes to accurate snap judgments of sexual orientation.

Wednesday, June 13, 2012

Brain correlates of resting, alert, and meditation states.

Posner and colleagues do a nice review of neural correlates of establishing, maintaining, and switching brain states.  I thought I would pass on a few chunks from their article describing the alert state and the meditation state:

The three brain states are compared in Table 1.


The meditation state differs from the alert state induced by a warning signal in several crucial ways. First, the alert state can be induced by the simple instruction to expect a target, without requiring any practice, whereas the meditation state requires specific instruction and practice. Second, the alert state requires an external target, whereas the meditation state may not involve a target event. Third, the alert state involves primarily the neuromodulator NE, whereas dopamine (DA) has often been shown to be important to the meditation state. Finally, the alert state involves a reduction in ACC activity, likely in order to keep the mind clear to perceive and respond quickly to the target. The meditation state, however, shows increased ACC activity that serves to regulate mind wandering. As mentioned previously, Five days of integrative mind-body training (IBMT) increases brain activity in the ACC, insula, and striatum. One month of IBMT improves white matter connectivity between the ACC, striatum, and other regions. Based on these results and related work, we propose the insula, ACC, and stiatum (IAS) as key neural correlates of changing brain states (Figure 2).


Because of its role in attention and self-regulation, we hypothesize that the ACC is involved in maintaining a state by reducing conflict with other states; the insula serves a primary role in switching between states, and the striatum is linked to the reward experience and formation of habits needed to make maintenance easier. The insula and ACC work together to support the role of the autonomic nervous system in maintaining the meditation state.

Tuesday, June 12, 2012

Your great grandparent's experience might have altered your stress response.

This fascinating nugget from Crews et a. (open access) adds to accumulating evidence on the importance of experience induced modification of our genomes that can be passed between generations. (The experiments are on mice, because obviously you don't do this kind of study directly on humans.)
Ancestral environmental exposures have previously been shown to promote epigenetic transgenerational inheritance and influence all aspects of an individual’s life history. In addition, proximate life events such as chronic stress have documented effects on the development of physiological, neural, and behavioral phenotypes in adulthood. We used a systems biology approach to investigate in male rats the interaction of the ancestral modifications carried transgenerationally in the germ line and the proximate modifications involving chronic restraint stress during adolescence. We find that a single exposure to a common-use fungicide (vinclozolin) three generations removed alters the physiology, behavior, metabolic activity, and transcriptome in discrete brain nuclei in descendant males, causing them to respond differently to chronic restraint stress. This alteration of baseline brain development promotes a change in neural genomic activity that correlates with changes in physiology and behavior, revealing the interaction of genetics, environment, and epigenetic transgenerational inheritance in the shaping of the adult phenotype. This is an important demonstration in an animal that ancestral exposure to an environmental compound modifies how descendants of these progenitor individuals perceive and respond to a stress challenge experienced during their own life history.

Monday, June 11, 2012

MindBlog's other lives

This post is sharing with readers two aspects of Deric's private life.  I studied visual transduction over a 36 year period (1960-1996), and on Saturday May 26, near a 70th birthday in May, my former students  gathered in Madison Wisconsin (one flying from Japan for the weekend!) for a laboratory reunion.  Several former Ph.D. or postdoctoral students now head their own laboratories, are department chairs, have chair professorships, or have won academic prizes.  In preparation for the reunion, I prepared a brief web history of the laboratory, and pictures of the reunion can be found here.


On the next day, Sunday May 27,  my partner Len (on right in the picture below) and I hosted a Social/Musical at our Twin Valley home (an 1860 stone schoolhouse converted to a residence) that was attended by friends as well as many who were at the laboratory reunion.  Music selections were from the romantic literature, by Chopin, Brahms, Faure, and Debussy. Pictures of that occasion can be found here.  Included in this post is a video of the Chopin C Minor Nocture played at the Social, recorded this past Saturday. I hope to do video recordings of several of the pieces played in the next period of time.)




   

Friday, June 08, 2012

Different sorts of suspicion - brain correlates

Bhatt et al. (open access) show brain correlates of the distinction between suspicion based on a person’s general beliefs about people in the world and the situation at hand, versus suspicion that is generated by the behavior of other people:
Humans assess the credibility of information gained from others on a daily basis; this ongoing assessment is especially crucial for avoiding exploitation by others. We used a repeated, two-person bargaining game and a cognitive hierarchy model to test how subjects judge the information sent asymmetrically from one player to the other. The weight that they give to this information is the result of two distinct factors: their baseline suspicion given the situation and the suspicion generated by the other person’s behavior. We hypothesized that human brains maintain an ongoing estimate of the credibility of the other player and sought to uncover neural correlates of this process. In the game, sellers were forced to infer the value of an object based on signals sent from a prospective buyer. We found that amygdala activity correlated with baseline suspicion, whereas activations in bilateral parahippocampus correlated with trial-by-trial uncertainty induced by the buyer’s sequence of suggestions. In addition, the less credible buyers that appeared, the more sensitive parahippocampal activation was to trial-by-trial uncertainty. Although both of these neural structures have previously been implicated in trustworthiness judgments, these results suggest that they have distinct and separable roles that correspond to their theorized roles in learning and memory.

Thursday, June 07, 2012

Why the liberals lost Wisconsin, and Obama may lose.

Last Tuesday the liberal bubble of Madison Wisconsin that I live in got reminded of what the rest of the state (and the U.S.) is really like:



I think this graphic from an article by Jonathan Haidt (whose book "The Righteous Mind" I'm reading, and strongly recommend you read) gives the most important part of the story. The conservative stance appeals to five of our evolved moral emotions, the liberal stance to only two.



Wednesday, June 06, 2012

Deep brain stimulation, fear extinction, and OCD suppression

Interesting work from Rodriguez-Romaguera et al. (open access):
Deep brain stimulation (DBS) of the ventral capsule/ventral striatum (VC/VS) reduces symptoms of intractable obsessive-compulsive disorder (OCD), but the mechanism of action is unknown. OCD is characterized by avoidance behaviors that fail to extinguish, and DBS could act, in part, by facilitating extinction of fear. We investigated this possibility by using auditory fear conditioning in rats, for which the circuits of fear extinction are well characterized. We found that DBS of the VS (the VC/VS homolog in rats) during extinction training reduced fear expression and strengthened extinction memory. Facilitation of extinction was observed for a specific zone of dorsomedial VS, just above the anterior commissure; stimulation of more ventrolateral sites in VS impaired extinction. DBS effects could not be obtained with pharmacological inactivation of either dorsomedial VS or ventrolateral VS, suggesting an extrastriatal mechanism. Accordingly, DBS of dorsomedial VS (but not ventrolateral VS) increased expression of a plasticity marker in the prelimbic and infralimbic prefrontal cortices, the orbitofrontal cortex, the amygdala central nucleus (lateral division), and intercalated cells, areas known to learn and express extinction. Facilitation of fear extinction suggests that, in accord with clinical observations, DBS could augment the effectiveness of cognitive behavioral therapies for OCD.

Tuesday, June 05, 2012

Embodied metaphors and creative acts

K.-y. Leung et al. do a series of studies that suggest that embodiment of metaphors for creativity promotes creative problem solving. Given that across cultures and languages (e.g., English, Korean, Hebrew, and Chinese), metaphors associate creativity with bilateral physical orientations (thinking about a problem “on one hand” and then “on the other hand”), a first study probed divergent thinking (fluency, flexibility, and originality) by asking participants to imagine multiple uses for a university building complex while gesturing with their right hand towards a wall. During a second trial, control participants generated additional ideas while raising the same hand they had raised during the first trial; participants in the experimental condition, however, switched hands by holding their left hand toward the wall and their right hand behind their back while they generated additional ideas (participants were not aware that they would have to generate answers to the same question on both trials until the second trial began.) The experimental subjects who changed hands generated more ideas, which were also more flexible and original.

A second two part experiment looked at the "think outside of the box" metaphor by seating participants inside or outside of a 5x5 ft. box, who carried out a convergent thinking task (think of a word that is related to three cue words. For example, “measure,” “worm,” and “video” might elicit the fourth word “tape”). Participants who completed such a remote associates test while they were physically outside the box generated more correct answers. In a variation on the box theme, divergent thinking was then probed by noting the effect of having participants physically embody a box by walking in a fixed, rectangular path. Participants who could move freely were more creative in imagining identities of ambiguous objects.

Two further studies dealt with the “putting two and two together” metaphor (by noting the effect of physically moving blocks on convergent thinking), and imagining bodily motions in a virtual world similar to those of physically enacting such metaphors (as in the first and second experiments).

Here is their abstract:
Creativity is a highly sought-after skill. Prescriptive advice for inspiring creativity abounds in the form of metaphors: People are encouraged to “think outside the box,” to consider a problem “on one hand, then on the other hand,” and to “put two and two together” to achieve creative breakthroughs. These metaphors suggest a connection between concrete bodily experiences and creative cognition. Inspired by recent advances in the understanding of body-mind linkages in the research on embodied cognition, we explored whether enacting metaphors for creativity enhances creative problem solving. Our findings from five studies revealed that both physical and psychological embodiment of metaphors for creativity promoted convergent thinking and divergent thinking (i.e., fluency, flexibility, or originality) in problem solving. Going beyond prior research, which focused primarily on the kind of embodiment that primes preexisting knowledge, we provide the first evidence that embodiment can also activate cognitive processes that facilitate the generation of new ideas and connections.

Monday, June 04, 2012

The power of network visualization.

A colleague of mine in the campus Chaos seminar pointed us to this 10 minute talk, which I found very engaging. It is given by Manuel Lima, who is senior UX design lead at Microsoft Bing:

Friday, June 01, 2012

Unconscious actions of testosterone

Here is an interesting observation from Terburg et al.:
Throughout vertebrate phylogeny, testosterone has motivated animals to obtain and maintain social dominance—a fact suggesting that unconscious primordial brain mechanisms are involved in social dominance. In humans, however, the prevailing view is that the neocortex is in control of primordial drives, and testosterone is thought to promote social dominance via conscious feelings of superiority, indefatigability, strength, and anger. Here we show that testosterone administration in humans prolongs dominant staring into the eyes of threatening faces that are viewed outside of awareness, without affecting consciously experienced feelings. These findings reveal that testosterone motivates social dominance in humans in much the same ways that it does in other vertebrates: involuntarily, automatically, and unconsciously.

Thursday, May 31, 2012

Quantitative analysis of language evolution.

Modern computation techniques and the mass digitization of books have made possible the systematic analysis of one of humankind's most important cultural artifacts, its languages. A analysis by Hughes et al. is quite different from studies in the dating of literary works, the analysis of the coarse-grained structure of literary history (and the evolution of genre), and most notably, a recent analysis of Google Books that examined temporal trends in content-word usage. (One of the co-authors of the study is a polymath, David Krakauer, who recently become Director of our Wisconsin Institute of Discovery here at the University of Wisconsin and is also Co-Director of its Center for Complexity and Collective Computation). Hughes et al. focus on the usage of content-free words as the basis of a first large-scale study of the similarity structure of literary style. Content-free words are the “syntactic glue” of a language: They are words that carry little meaning on their own but form the bridge between words that convey meaning. Their joint frequency of usage is known to provide a useful stylistic fingerprint for authorship, and thus suggests a method of comparing author styles. Their dataset was a subset of 537 authors in the Project Gutenberg database composed of those who wrote after the year 1550, had at least five works in English in the Project Gutenberg collection, and for whom birth and death date information was available. The primary results of the analysis are that time provides the most coherent means of clustering work and that a trend of diminishing stylistic influence is observed as one moves forward in time. Such a finding is consistent with a simple evolutionary model for stylistic influence, which assumes that imitation attends preferentially to contemporary authors. The authors uncover quantitative support of the previously purely anecdotal notion of a literary “style of a time.” They note that their findings suggest the utility and perhaps the creation of a new field of stylometric analysis in culturomics. Here is their abstract:
Literature is a form of expression whose temporal structure, both in content and style, provides a historical record of the evolution of culture. In this work we take on a quantitative analysis of literary style and conduct the first large-scale temporal stylometric study of literature by using the vast holdings in the Project Gutenberg Digital Library corpus. We find temporal stylistic localization among authors through the analysis of the similarity structure in feature vectors derived from content-free word usage, nonhomogeneous decay rates of stylistic influence, and an accelerating rate of decay of influence among modern authors. Within a given time period we also find evidence for stylistic coherence with a given literary topic, such that writers in different fields adopt different literary styles. This study gives quantitative support to the notion of a literary “style of a time” with a strong trend toward increasingly contemporaneous stylistic influence.
It seems a bit amazing that their analysis of the use of 307 content-free words that included prepositions, articles, conjunctions, “to be” verbs, and some common nouns and pronouns allowed them to cluster authors in time and by narrative theme, and that content-free word frequencies were found to be fairly faithfully transmitted among authors of a similar period, even when imitation at this level of textual resolution seems to be out of the question. Moving into the present, this imitation becomes increasingly localized to our contemporaries. Further edited clips:
We propose that for the earliest periods in our dataset, and through the early modern period, the number of published works remained relatively low. This allowed authors to have sufficient time to sample (read) very broadly from the full range of historically published works. Common phrasing, and norms of syntax and grammar, remain relatively unchanged for long periods of time. This generates decay rates in similarity as a function of temporal distance that are not significantly different from the average, because authors are influenced by models distributed uniformly in time. However, for more recent authors, the number of possible choices of books to read has increased dramatically, and with a finite amount of time, a subset of these works must be chosen, leading to rather heterogeneous reading patterns and a greater overall diversity of authored works. The pattern accelerates in the later modern period, with even more authors to choose from and selection dominated by contemporaneous authors. This suggests a simple evolutionary model for patterns of influence.
The negative influence of authors from a preceding generation in the period 1907–1952 could be explained by the Modernist movement. Modernist authors, who are contained within this time period, display a radical shift in style as they reject their immediate stylistic predecessors yet remain a part of a dominant movement that included many of their contemporaries. The contemporary influence of writing programs and their often close readings of contemporary works and feedback (sometimes called “reflexive modernism”) has also been suggested to contribute to this effect. The overall pattern that we find is that the stylistic influence of the past is diminishing at an increasing rate, which suggests that style itself is evolving at an accelerating pace.
The patterns of influence are a first discovery from the corpus. Implicit in this is a temporal clustering of similarity and quantitative support for the qualitative suggestions of a notion of a “style of a time.” It is also worth noting that the implicit temporal clustering of similarity is not an exclusively temporal phenomenon. A network representation of the authors reveals evidence of thematic clustering as well. Examples include interesting groupings of English poets and playwrights, military leaders, and a collection of important naturalists, social thinkers, and historians. This is suggestive and supportive of the hypothesis that word frequencies are not only typical of a given time but also of a field of inquiry. Historians and naturalists do not only write about different topics, they write about them differently. Taken together with the patterns of decay in influence this suggests that whereas authors of the 18th and 19th centuries continued to be influenced by previous centuries, authors of the late 20th century are strongly influenced by authors from their own decade. The so-called “anxiety of influence”, whereby authors are understood in terms of their response to canonical precursors, is becoming an “anxiety of impotence,” in which the past exerts a diminishing stylistic influence on the present. These results are consistent with many complex, scaling phenomena such as those found in urban and technological systems, where there has been an accelerating rate of change into the present. This is a rather intriguing pattern of short-term cultural evolution that is different from the constant rates of change reported for names and pottery or the reduced rates of lexical substitution of frequently used words over thousands of years. Further analysis will elucidate not only the transmission mechanisms generating temporally localized styles but additional stylistic factors that help differentiate the style of one author from that of another.

Wednesday, May 30, 2012

Social jetlag and obesity.

Roenneberg et al. do an epidemiological study, showing that, beyond sleep duration, the difference between natural circadian sleep rhythm and the actual times of sleep people observe (social jetlag) is associated with increased body mass index. They suggest that living “against the clock” may be a factor contributing to the modern epidemic of obesity. (But... it seems to me people were doing this before the obesity epidemic was noted. Most experts attribute the epidemic to increased physical inactivity and abundance of cheap highly caloric foods.) Here is their summary and abstract:
-In 70% of the population, biological and social clocks differ by >1 hr (social jetlag) -Social jetlag is a predictor of BMI, especially for overweight individuals -The decrease of sleep duration over the past decade concerns only workdays -Individuals are progressively exposed to decreasing light, and their chronotypes delay
Abstract
Obesity has reached crisis proportions in industrialized societies. Many factors converge to yield increased body mass index (BMI). Among these is sleep duration. The circadian clock controls sleep timing through the process of entrainment. Chronotype describes individual differences in sleep timing, and it is determined by genetic background, age, sex, and environment (e.g., light exposure). Social jetlag quantifies the discrepancy that often arises between circadian and social clocks, which results in chronic sleep loss. The circadian clock also regulates energy homeostasis, and its disruption—as with social jetlag—may contribute to weight-related pathologies. Here, we report the results from a large-scale epidemiological study, showing that, beyond sleep duration, social jetlag is associated with increased BMI. Our results demonstrate that living “against the clock” may be a factor contributing to the epidemic of obesity. This is of key importance in pending discussions on the implementation of Daylight Saving Time and on work or school times, which all contribute to the amount of social jetlag accrued by an individual. Our data suggest that improving the correspondence between biological and social clocks will contribute to the management of obesity.

Tuesday, May 29, 2012

Social interactions prime us for motor empathy or resonance.

Hogeveen and Obhi1 find that recent experience tunes our mirroring systems to particular agent types. A bit from their introduction, followed by the abstract:
Detecting and responding to biological stimuli such as predators or potential mates is a fundamental and adaptive capability, supported by rain areas such as the posterior superior temporal sulcus (pSTS) which is biased for processing biological motion. The pSTS and the parietofrontal mirror system form part of a wider action observation network (AON), which is thought to underlie many social abilities. Motor resonance (MR) is the activation of matching motor representations during observation of action(s) made by others, and could index mirror activity within the wider AON.
Understanding the neural basis of social behavior has become an important goal for cognitive neuroscience and a key aim is to link neural processes observed in the laboratory to more naturalistic social behaviors in real-world contexts. Although it is accepted that mirror mechanisms contribute to the occurrence of motor resonance (MR) and are common to action execution, observation, and imitation, questions remain about mirror (and MR) involvement in real social behavior and in processing nonhuman actions. To determine whether social interaction primes the MR system, groups of participants engaged or did not engage in a social interaction before observing human or robotic actions. During observation, MR was assessed via motor-evoked potentials elicited with transcranial magnetic stimulation. Compared with participants who did not engage in a prior social interaction, participants who engaged in the social interaction showed a significant increase in MR for human actions. In contrast, social interaction did not increase MR for robot actions. Thus, naturalistic social interaction and laboratory action observation tasks appear to involve common MR mechanisms, and recent experience tunes the system to particular agent types.

Monday, May 28, 2012

Serotonin modulates reward value in our decision making.

Seymour et al. find further behavioral and neural evidence that serotonin modulates (is necessary for) distinct behavioral and anatomical components of decision-making. Most surprising is their observation of a strongly positive dependence of reward outcome value on serotonin signaling, with corresponding cue-value-related activity in vmPFC and prediction-error-related activity in dorsolateral putamen (for errors). This value-dependent effect was behaviorally and anatomically distinct from an effect of serotonin on behavioral flexibility, as indicated by choice perseveration. Here is their abstract:
Establishing a function for the neuromodulator serotonin in human decision-making has proved remarkably difficult because if its complex role in reward and punishment processing. In a novel choice task where actions led concurrently and independently to the stochastic delivery of both money and pain, we studied the impact of decreased brain serotonin induced by acute dietary tryptophan depletion. Depletion selectively impaired both behavioral and neural representations of reward outcome value, and hence the effective exchange rate by which rewards and punishments were compared. This effect was computationally and anatomically distinct from a separate effect on increasing outcome-independent choice perseveration. Our results provide evidence for a surprising role for serotonin in reward processing, while illustrating its complex and multifarious effects.

Friday, May 25, 2012

The neurogenetics of nice.

Interesting observations from Poulin et al...They note that all prosocial acts require people to contend with concerns about potential exploitation or loss of resources (i.e., threats). If oxytocin and vasopressin moderate responses to such threats, they may influence a wide variety of prosocial behaviors, including those outside a laboratory context. It is known that oxytocin administration reduces amygdalar reactivity to negative stimuli,and amygdalar reactivity, in turn, mediates oxytocin’s effects on generosity in the context of an economic game. The G/G genotype of the rs53576 single-nucleotide polymorphism (SNP) for OXTR also predicts lower cardiovascular reactivity to startle anticipation than do the A/A and A/G genotypes. Here is their abstract:
Oxytocin, vasopressin, and their receptor genes influence prosocial behavior in the laboratory and in the context of close relationships. These peptides may also promote social engagement following threat. However, the scope of their prosocial effects is unknown. We examined oxytocin receptor (OXTR) polymorphism rs53576, as well as vasopressin receptor 1a (AVPR1a) polymorphisms rs1 and rs3 in a national sample of U.S. residents (n = 348). These polymorphisms interacted with perceived threat to predict engagement in volunteer work or charitable activities and commitment to civic duty. Specifically, greater perceived threat predicted engagement in fewer charitable activities for individuals with A/A and A/G genotypes of OXTR rs53576, but not for G/G individuals. Similarly, greater perceived threat predicted lower commitment to civic duty for individuals with one or two short alleles for AVPR1a rs1, but not for individuals with only long alleles. Oxytocin, vasopressin, and their receptor genes may significantly influence prosocial behavior and may lie at the core of the caregiving behavioral system.

Thursday, May 24, 2012

Higher maternal cortisol correlates with later affective problems.

Sobering data from Buss et al:
Stress-related variation in the intrauterine milieu may impact brain development and emergent function, with long-term implications in terms of susceptibility for affective disorders. Studies in animals suggest limbic regions in the developing brain are particularly sensitive to exposure to the stress hormone cortisol. However, the nature, magnitude, and time course of these effects have not yet been adequately characterized in humans. A prospective, longitudinal study was conducted in 65 normal, healthy mother–child dyads to examine the association of maternal cortisol in early, mid-, and late gestation with subsequent measures at approximately 7 y age of child amygdala and hippocampus volume and affective problems. After accounting for the effects of potential confounding pre- and postnatal factors, higher maternal cortisol levels in earlier but not later gestation was associated with a larger right amygdala volume in girls (a 1 SD increase in cortisol was associated with a 6.4% increase in right amygdala volume), but not in boys. Moreover, higher maternal cortisol levels in early gestation was associated with more affective problems in girls, and this association was mediated, in part, by amygdala volume. No association between maternal cortisol in pregnancy and child hippocampus volume was observed in either sex. The current findings represent, to the best of our knowledge, the first report linking maternal stress hormone levels in human pregnancy with subsequent child amygdala volume and affect. The results underscore the importance of the intrauterine environment and suggest the origins of neuropsychiatric disorders may have their foundations early in life.

Wednesday, May 23, 2012

Seeing where our brains think about our thinking

More fascinating work from Ray Dolan's group at the Wellcome Trust Center for Neuroimaging at University College, London:
Neuroscience has made considerable progress in understanding the neural substrates supporting cognitive performance in a number of domains, including memory, perception, and decision making. In contrast, how the human brain generates metacognitive awareness of task performance remains unclear. Here, we address this question by asking participants to perform perceptual decisions while providing concurrent metacognitive reports during fMRI scanning. We show that activity in right rostrolateral prefrontal cortex (rlPFC) satisfies three constraints for a role in metacognitive aspects of decision-making. Right rlPFC showed greater activity during self-report compared to a matched control condition, activity in this region correlated with reported confidence, and the strength of the relationship between activity and confidence predicted metacognitive ability across individuals. In addition, functional connectivity between right rlPFC and both contralateral PFC and visual cortex increased during metacognitive reports. We discuss these findings in a theoretical framework where rlPFC re-represents object-level decision uncertainty to facilitate metacognitive report.
I'll also pass on Figure 5 and it's legend from the text:

Individual difference and connectivity analyses. The top panel illustrates the significant correlation between confidence-related activity in right rlPFC and metacognitive accuracy across subjects. The bottom panel depicts results of an exploratory psychophysiological interaction analysis (displayed at p < 0.001, uncorrected), revealing whole-brain corrected (p < 0.05) increases in connectivity between right rlPFC and visual cortex (lingual gyrus) and between right rlPFC and left dlPFC in Report compared to Follow trials.

Tuesday, May 22, 2012

My amygdala made me do it...

James Atlas writes an engaging piece on a topic that has been the subject of many MindBlog posts: how our supposedly rational 'upstairs' decisions are actually nudged or determined by unconscious or implicit 'downstairs' mechanisms. He doesn't include in his list of recent books Jonathan Haidt's "The Righteous Mind", which is beautifully written and one of those few books I actually read through, rather than just reading its reviews. A few clips from the Atlas article:
WHY are we thinking so much about thinking these days?...Jonah Lehrer’s “Imagine: How Creativity Works,” ...Charles Duhigg’s book “The Power of Habit: Why We Do What We Do in Life and Business,” ...“Subliminal: How Your Unconscious Mind Rules Your Behavior,” by Leonard Mlodinow...Kahneman's “Thinking, Fast and Slow” goes to the heart of the matter: How aware are we of the invisible forces of brain chemistry, social cues and temperament that determine how we think and act? Has the concept of free will gone out the window?
These books possess a unifying theme: The choices we make in day-to-day life are prompted by impulses lodged deep within the nervous system. Not only are we not masters of our fate; we are captives of biological determinism. Once we enter the portals of the strange neuronal world known as the brain, we discover that — to put the matter plainly — we have no idea what we’re doing.
The 18th-century philosopher David Hume (much quoted by Mr. Lehrer) didn’t have an M.R.I. scanner at his disposal, but he framed the question in much the same way. His major work, “A Treatise of Human Nature,” explored the ways in which habit, or “custom,” rules our lives. Hume’s experiments with perception — how we respond to colors, distance, numerical sets — prefigure the rigorous science of Professor Kahneman. His intent was to show us “the natural infirmity and unsteadiness both of our imagination and senses.” Consciousness, like philosophy itself, stands on a “weak foundation.”
If Hume seems modern, William James reads like a contemporary. Writing toward the end of the 19th century, James addressed the same question that had concerned Hume — how the unconscious operates as a physical process, not just, as Freud would have it, a mental one. In his now-classic essay, “Habit,” he argued that even our most complex acts are reflexive — “concatenated discharges in the nerve-centres.” ...we can train ourselves to change if we work at it hard enough. Self-awareness sets us free. “The great thing, then, in all education,” writes James, “is to make our nervous system our ally instead of our enemy.”
Does this mean we have no “agency,” no capacity to act on our own? Or can autonomy thrive within the prison of self-ignorance? “We have to believe it does,” says Steven Lukes, a professor of sociology at New York University highly admired for his work in moral philosophy. “If we seriously thought that our intentions made no difference to how we behave, we couldn’t go on using the language of ethics. How would we go on living the lives we live?” Or doing what we think is right? “People have free will when they ‘feel’ they have free will,” says Professor Kahneman. “If we didn’t believe in it, we would have no responsibility.”
But of course what one “feels,” as we’ve learned from all these books, could well be — indeed, probably is — an illusion. As Timothy Wilson puts it with haunting simplicity: “We are strangers to ourselves.” Hopefully...Strangers who can learn how to be friends.
The sentiments above are very much in the vein of my "I-Illusion" web lecture.

Monday, May 21, 2012

Further cognitive advantages of bilinguals.

Interesting work from Krizman et al.:
Bilingualism profoundly affects the brain, yielding functional and structural changes in cortical regions dedicated to language processing and executive function [Crinion J, et al. (2006) Science 312:1537–1540; Kim KHS, et al. (1997) Nature 388:171–174]. Comparatively, musical training, another type of sensory enrichment, translates to expertise in cognitive processing and refined biological processing of sound in both cortical and subcortical structures. Therefore, we asked whether bilingualism can also promote experience-dependent plasticity in subcortical auditory processing. We found that adolescent bilinguals, listening to the speech syllable [da], encoded the stimulus more robustly than age-matched monolinguals. Specifically, bilinguals showed enhanced encoding of the fundamental frequency, a feature known to underlie pitch perception and grouping of auditory objects. This enhancement was associated with executive function advantages. Thus, through experience-related tuning of attention, the bilingual auditory system becomes highly efficient in automatically processing sound. This study provides biological evidence for system-wide neural plasticity in auditory experts that facilitates a tight coupling of sensory and cognitive functions.

Friday, May 18, 2012

Reunion of Bownds' Vision Laboratory

Before I started the thread of reading and writing that led to this MindBlog, I spent 35 years doing laboratory experiments on how the rods and cones or our retinas change light into a nerve signal. Next weekend, on the occasion of my 70th birthday, many of the researchers, graduate students, and postdoctoral students who passed through my laboratory are assembling back here in Madison for a laboratory reunion. For this reunion I've pasted together some laboratory history showing pictures, listing contributions, etc., and thought I would pass it on for MindBlog readers who might be curious about my past.

Thursday, May 17, 2012

Emotion reversed in the brains of left handers.

Fascinating observations from Brookshire and Casasanto:
According to decades of research on affective motivation in the human brain, approach motivational states are supported primarily by the left hemisphere and avoidance states by the right hemisphere. The underlying cause of this specialization, however, has remained unknown. Here we conducted a first test of the Sword and Shield Hypothesis (SSH), according to which the hemispheric laterality of affective motivation depends on the laterality of motor control for the dominant hand (i.e., the “sword hand," used preferentially to perform approach actions) and the nondominant hand (i.e., the “shield hand," used preferentially to perform avoidance actions).
To determine whether the laterality of approach motivation varies with handedness, we measured alpha-band power (an inverse index of neural activity) in right- and left-handers during resting-state electroencephalography and analyzed hemispheric alpha-power asymmetries as a function of the participants' trait approach motivational tendencies. Stronger approach motivation was associated with more left-hemisphere activity in right-handers, but with more right-hemisphere activity in left-handers.
The hemispheric correlates of approach motivation reversed between right- and left-handers, consistent with the way they typically use their dominant and nondominant hands to perform approach and avoidance actions. In both right- and left-handers, approach motivation was lateralized to the same hemisphere that controls the dominant hand. This covariation between neural systems for action and emotion provides initial support for the SSH.

Wednesday, May 16, 2012

Compounds that increase muscle endurance also enhance cognition

Recent experiments from Kobilo et al. build on several studies that have shown that exercise enhances cognition (in both humans and mice). They show that giving sedentary mice either of two drugs that induce the same kinds of changes in their muscles that exercise does enhances their performance in subsequent tests of memory and learning. Since these drugs do not cross the blood-brain barrier, peripheral triggers appear be activating the cellular and molecular cascades in the brain that lead to improvements in cognition.
Physical activity improves learning and hippocampal neurogenesis. It is unknown whether compounds that increase endurance in muscle also enhance cognition. We investigated the effects of endurance factors, peroxisome proliferator-activated receptor δ agonist GW501516 and AICAR, activator of AMP-activated protein kinase on memory and neurogenesis. Mice were injected with GW for 7 d or AICAR for 7 or 14 d. Two weeks thereafter mice were tested in the Morris water maze. AICAR (7 d) and GW improved spatial memory. Moreover, AICAR significantly, and GW modestly, elevated dentate gyrus neurogenesis. Thus, pharmacological activation of skeletal muscle may mediate cognitive effects.

Tuesday, May 15, 2012

Universality of facial expressions of emotion challenged.

This  work by Jack et al (open access to full article) comes as quite a challenge to the prevailing orthodoxy on the universality of human facial movements associated with the six basic emotional states:
Since Darwin’s seminal works, the universality of facial expressions of emotion has remained one of the longest standing debates in the biological and social sciences. Briefly stated, the universality hypothesis claims that all humans communicate six basic internal emotional states (happy, surprise, fear, disgust, anger, and sad) using the same facial movements by virtue of their biological and evolutionary origins [Susskind JM, et al. (2008) Nat Neurosci 11:843–850]. Here, we refute this assumed universality. Using a unique computer graphics platform that combines generative grammars [Chomsky N (1965) MIT Press, Cambridge, MA] with visual perception, we accessed the mind’s eye of 30 Western and Eastern culture individuals and reconstructed their mental representations of the six basic facial expressions of emotion. Cross-cultural comparisons of the mental representations challenge universality on two separate counts. First, whereas Westerners represent each of the six basic emotions with a distinct set of facial movements common to the group, Easterners do not. Second, Easterners represent emotional intensity with distinctive dynamic eye activity. By refuting the long-standing universality hypothesis, our data highlight the powerful influence of culture on shaping basic behaviors once considered biologically hardwired. Consequently, our data open a unique nature–nurture debate across broad fields from evolutionary psychology and social neuroscience to social networking via digital avatars.

Monday, May 14, 2012

Linking social environment to gene expression.

Tung et al. report work on rhesus macaque monkeys - consonant with more limited human studies - showing that dominance rank causes a plastic imprint on regulation of immune system genes. They find that social status can be predicted by gene expression data with 80% accuracy.
Variation in the social environment is a fundamental component of many vertebrate societies. In humans and other primates, adverse social environments often translate into lasting physiological costs. The biological mechanisms associated with these effects are therefore of great interest, both for understanding the evolutionary impacts of social behavior and in the context of human health. However, large gaps remain in our understanding of the mechanisms that mediate these effects at the molecular level. Here we addressed these questions by leveraging the power of an experimental system that consisted of 10 social groups of female macaques, in which each individual's social status (i.e., dominance rank) could be experimentally controlled. Using this paradigm, we show that dominance rank results in a widespread, yet plastic, imprint on gene regulation, such that peripheral blood mononuclear cell gene expression data alone predict social status with 80% accuracy. We investigated the mechanistic basis of these effects using cell type-specific gene expression profiling and glucocorticoid resistance assays, which together contributed to rank effects on gene expression levels for 694 (70%) of the 987 rank-related genes. We also explored the possible contribution of DNA methylation levels to these effects, and identified global associations between dominance rank and methylation profiles that suggest epigenetic flexibility in response to status-related behavioral cues. Together, these results illuminate the importance of the molecular response to social conditions, particularly in the immune system, and demonstrate a key role for gene regulation in linking the social environment to individual physiology.

Friday, May 11, 2012

Egalitarian behavior and the insula.

Fascinating work from Dawes et al.:
Individuals are willing to sacrifice their own resources to promote equality in groups. These costly choices promote equality and are associated with behavior that supports cooperation in humans, but little is known about the brain processes involved. We use functional MRI to study egalitarian preferences based on behavior observed in the “random income game.” In this game, subjects decide whether to pay a cost to alter group members’ randomly allocated incomes. We specifically examine whether egalitarian behavior is associated with neural activity in the ventromedial prefrontal cortex and the insular cortex, two regions that have been shown to be related to social preferences. Consistent with previous studies, we find significant activation in both regions; however, only the insular cortex activations are significantly associated with measures of revealed and expressed egalitarian preferences elicited outside the scanner. These results are consistent with the notion that brain mechanisms involved in experiencing the emotional states of others underlie egalitarian behavior in humans.
From their discussion:
...this experiment shows that some parts of the brain are more active during egalitarian outcomes, and these activations are correlated with egalitarian behavior inside the scanner. However, a more crucial result is that the activations are also correlated with behavior outside the scanner, including self-reported preferences for egalitarian outcomes and game behavior that reveals how willing subjects are to use their own resources to obtain egalitarian outcomes within their groups. Taken together, the evidence suggests that the anterior insular cortex plays a critical role in egalitarian behavior in humans. This conclusion is consistent with a broader view of the insular cortex as a neural substrate that processes the relationship of the individual with respect to his or her environment. The predominately left-lateralized activation may point toward the possibility of a positive valence or energy-preserving mode related processing during egalitarian behavior (i.e., individuals may see the group as a greater good that is worth preserving). The fact that the insula is directly involved in physiological, food, and pain-related processing supports the general notion that prosocial behavior, which is important for survival of both the individual and the group/species, is implemented on a fundamental physiological level similar to breathing, heartbeat, hunger, and pain.

Adam Smith contended that moral sentiments like egalitarianism derived from a “fellow-feeling” that would increase with our level of sympathy for others, predicting not merely aversion to inequity, but also our propensity to engage in egalitarian behaviors. The evidence here supports such an interpretation. Although individuals may experience internal rewards when punishing antisocial behavior and may have preferences for social equality, our results suggest that it is the brain mechanisms involved in experiencing the emotional and social states of self and others that appear to be driving egalitarian behaviors.

Our results have important implications for theories of the evolution of prosocial behavior that suggest culturally transmitted “leveling mechanisms”—for example, food sharing and monogamy—stifle within-group competition and create circumstances in which intergroup antagonism generates selective pressure for altruistic behaviors. A concern for equality may have originally evolved because it fostered the conditions necessary for early human groups to maintain a high level of cooperation. Future research should focus on the interconnectivity of regions of the brain involved in egalitarianism and altruism to better understand how these two behaviors may have coevolved.

Thursday, May 10, 2012

Choosing whether you are anxious or chilled out - a toolkit.

This is a followup on my May 2 post, which provided a link to a lecture that I now have given (this past Tuesday) to the Chaos and Complex Systems Seminar series here at UW Madison. Responses to that talk have been very positive. I thought I would suggest that MindBlog readers who want to get quickly to the "bottom line" click straight through the presentation to the fourth part of the talk (4. What are the regulators of calm and stress to which we have conscious access?), which describes a toolkit of "bottom-up" and "top-down" approaches or techniques that can influence whether we are calm or losing it.

The topics:
1. Structures of calm and arousal: What machinery has been cobbled together over evolutionary time? 2. What is going on in our brains and bodies during calm or stress?
3. What is the nature of the self that is having this experience?
4. What are the regulators of calm and stress to which we have conscious access?

Wednesday, May 09, 2012

12 month old human infants recognize stable social dominance relations.

Interesting work from Mascaro and Csibra. They presented several dominance scenarios with block figures to infants, and then examined mean looking time when the dominance relation that the infant had become familiar with was subsequently violated. In the first study, for example, 9- and 12-mo-old infants were shown short animations depicting the actions of two agents. First, the “subordinate” agent was seen collecting small objects. Then the “dominant” agent entered and started to collect objects while the subordinate one let it succeed. In the second study, Twelve- and 15-mo-old infants watched familiarization events in which the agents did not collect objects but competed to stay in a little area, the boundaries of which were delimited by walls. First, the subordinate agent entered the area alone. Then the dominant agent arrived and monopolized the little area by repeatedly pushing the subordinate agent away. In subsequent viewings these dominance relations were either confirmed or violated. Mean gaze time increased significantly when the familiarized sequence was violated. Here is their abstract:
What are the origins of humans’ capacity to represent social relations? We approached this question by studying human infants’ understanding of social dominance as a stable relation. We presented infants with interactions between animated agents in conflict situations. Studies 1 and 2 targeted expectations of stability of social dominance. They revealed that 15-mo-olds (and, to a lesser extent, 12-mo-olds) expect an asymmetric relationship between two agents to remain stable from one conflict to another. To do so, infants need to infer that one of the agents (the dominant) will consistently prevail when her goals conflict with those of the other (the subordinate). Study 3 and 4 targeted the format of infants’ representation of social dominance. In these studies, we found that 12- and 15-mo-olds did not extend their expectations of dominance to unobserved relationships, even when they could have been established by transitive inference. These results suggest that infants' expectation of stability originates from their representation of social dominance as a relationship between two agents rather than as an individual property. Infants’ demonstrated understanding of social dominance reflects the cognitive underpinning of humans’ capacity to represent social relations, which may be evolutionarily ancient, and may be shared with nonhuman species.
In study 1,

Tuesday, May 08, 2012

Further work on when two heads are better or worse than one.

Studies that compare the accuracy of individual and group decision yield somewhat inconsistent results. The key to benefiting from other minds is to know when to rely on the group and when to walk alone. To follow up a thread started in two previous posts (here and here) on when two heads are better or worse than one, I pass on this work by Koriat. He shows that in an inference task involving two alternatives, optimal results are obtained with the simple heuristic of selecting the response expressed with the higher—or in the case of more than two heads, highest—degree of confidence. Here is the abstract:
A recent study, using a perceptual task, indicated that two heads were better than one provided that the members could communicate freely, presumably sharing their confidence in their judgments. Capitalizing on recent work on subjective confidence, I replicated this effect in the absence of any dyadic interaction by selecting on each trial the decision of the more confident member of a virtual dyad. However, because subjective confidence monitors the consensuality rather than the accuracy of a decision, when most participants were in error, reliance on the more confident member yielded worse decisions than those of the better individual. Assuming that for each issue group decisions are dominated by the more confident member, these results help specify when groups will be more or less accurate than individuals.
:

Monday, May 07, 2012

Brain correlates of whether we help someone suffering.

I thought I would pass on this interesting paper that is being discussed by an emotion seminar group here on the Univ. of Wisc. campus.  Hein et al. touch on the question of whether we are fundamentally good or bad. Is our human nature always fundamentally prosocial?   They find it depends very much on whether we are helping one of "us" or one of "them."  Their summary of the main points, followed by their abstract:
  • Empathy-related brain responses in anterior insula predict costly helping
  • Helping ingroup and outgroup members is predicted by distinct neural responses
  • Brain responses predict behavior toward outgroup members better than self-reports
Little is known about the neurobiological mechanisms underlying prosocial decisions and how they are modulated by social factors such as perceived group membership. The present study investigates the neural processes preceding the willingness to engage in costly helping toward ingroup and outgroup members. Soccer fans witnessed a fan of their favorite team (ingroup member) or of a rival team (outgroup member) experience pain. They were subsequently able to choose to help the other by enduring physical pain themselves to reduce the other's pain. Helping the ingroup member was best predicted by anterior insula activation when seeing him suffer and by associated self-reports of empathic concern. In contrast, not helping the outgroup member was best predicted by nucleus accumbens activation and the degree of negative evaluation of the other. We conclude that empathy-related insula activation can motivate costly helping, whereas an antagonistic signal in nucleus accumbens reduces the propensity to help.

Friday, May 04, 2012

Metaphors are the tip of the mind's iceberg.

An essay by Benjamin Bergen does a nice summary of the importance of ideas in Lakoff and Johnson's 1980 book, "Metaphors We Live By."  (I remember being completely awed and fascinated by this book when it appeared.) They established the point that metaphor is not linguistic window-dressing, it reveals fundamental operations of mind.
...Lakoff and Johnson observed that real metaphorical language as actually used isn't haphazard at all. Instead, it's systematic and coherent...Metaphor is unidirectional, from concrete to abstract.(You can't reverse metaphors. While you can say "He's clean" to mean he has no criminal record, you can't say "He's moral" to mean that he bathed recently.)
Metaphorical expressions are coherent with one another. Take the example of understanding and seeing. ...You always describe the understander as the seer, the understood idea as the seen object, the act of understanding as seeing, the understandability of the idea as the visibility of the object, and so on. In other words, the aspects of seeing you use to talk about aspects of understanding stand in a fixed mapping to one another.

These observations led Lakoff and Johnson to propose that there was something going on with metaphor that was deeper than just the words. They argued that the metaphorical expressions in language are really only surface phenomena, organized and generated by mappings in people's minds. For them, the reason metaphorical language exists and the reason why it's systematic and coherent is that people think metaphorically. You don't just talk about understanding as seeing; you think about understanding as seeing. You don't just talk about morality as cleanliness; you think about morality as cleanliness. And it's because you think metaphorically—because you systematically map certain concepts onto others in your mind—that you talk metaphorically. The metaphorical expressions are merely the visible tip of the iceberg.

As explanations go, this one covers all the bases. It's elegant in that it explains messy and complicated phenomena (the various metaphorical expressions we have that describe understanding as seeing, for instance) in terms of something much simpler—a structured mapping between the two conceptual domains in people's minds. It's powerful in that it explains things other than metaphorical language—recent work in cognitive psychology shows that people think metaphorically even in the absence of metaphorical language; affection as warmth, morality as cleanliness. As a result, the conceptual metaphor explanation helps to explain how it is that we understand abstract concepts like affection or morality at all—by metaphorically mapping them onto more concrete ones.

...the conceptual metaphor explanation is transformative—it flies in the face of the accepted idea that metaphor is just a linguistic device based on similarity. In an instant, it made us rethink 2000 years of received wisdom.

Thursday, May 03, 2012

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.

Wednesday, May 02, 2012

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. 

Monday, April 30, 2012

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.

Friday, April 27, 2012

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.

Thursday, April 26, 2012

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.'

Wednesday, April 25, 2012

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.)

Tuesday, April 24, 2012

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.

Monday, April 23, 2012

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.

Friday, April 20, 2012

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.

Thursday, April 19, 2012

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.

Wednesday, April 18, 2012

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.

Tuesday, April 17, 2012

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.