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.
This blog reports new ideas and work on mind, brain, behavior, psychology, and politics - as well as random curious stuff. (Try the Dynamic Views at top of right column.)
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:
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.
Blog Categories:
fear/anxiety/stress,
human development
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.
Blog Categories:
consciousness,
self,
self help,
unconscious
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.
Blog Categories:
animal behavior,
fear/anxiety/stress,
genes
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?
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:
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.
- 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
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.
-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 backgroundsFrom 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.
Blog Categories:
embodied cognition,
emotion,
mirror neurons
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:
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.)
...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.
Blog Categories:
brain plasticity,
fear/anxiety/stress,
meditation
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.
Liljeholm and O'Doherty also offer context and perspective on this work.
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.
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.")Further points:
-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.")
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.
Monday, April 16, 2012
Two different ways of making choices in two brain areas.
Kolling et al. note brain correlates of two different ways of making decisions. They use fMRI of humans to examine neural correlates of foraging, which involves a choice of whether or not to engage with options as they are encountered (which is different from the sort of binary choice between currently available options studied by behavioral economics.) Here is their abstract:
Behavioral economic studies involving limited numbers of choices have provided key insights into neural decision-making mechanisms. By contrast, animals’ foraging choices arise in the context of sequences of encounters with prey or food. On each encounter, the animal chooses whether to engage or, if the environment is sufficiently rich, to search elsewhere. The cost of foraging is also critical. We demonstrate that humans can alternate between two modes of choice, comparative decision-making and foraging, depending on distinct neural mechanisms in ventromedial prefrontal cortex (vmPFC) and anterior cingulate cortex (ACC) using distinct reference frames; in ACC, choice variables are represented in invariant reference to foraging or searching for alternatives. Whereas vmPFC encodes values of specific well-defined options, ACC encodes the average value of the foraging environment and cost of foraging.
Friday, April 13, 2012
More on why exercise is so good for us...
Many studies show that egular physical activity confers enormous fitness benefits. Exercise training enhances muscular endurance and strength, expends calories, and combats the development of common diseases such as obesity and type 2 diabetes. The effects of exercise are systemic and seemingly cannot be explained solely by the expenditure of calories in muscle. Daniel Kelly writes a perspective on recent work showing how a new protein messenger named irisin (after Iris, the Greek messenger goddess) is released during muscle activity and triggers remodeling and energy expenditure in distant subcutaneous fat tissue deposits. Here is a summary figure of the muscle cell (myocyte) - fat cell (adipocyte) connection.
Figure: The proposed irisin messenger system is depicted for humans [but was characterized in mice]. Exercise and energy expenditure induces the transcriptional regulator PGC-1α in the skeletal myocyte, which in turn drives the production of the membrane protein FNDC5. The circulating factor irisin, cleaved from FNDC5, activates thermogenic programs in white adipose tissue (“browning”), including mitochondrial biogenesis and the expression of uncoupling protein 1 (UCP1), leading to mitochondrial heat production and energy expenditure.
Figure: The proposed irisin messenger system is depicted for humans [but was characterized in mice]. Exercise and energy expenditure induces the transcriptional regulator PGC-1α in the skeletal myocyte, which in turn drives the production of the membrane protein FNDC5. The circulating factor irisin, cleaved from FNDC5, activates thermogenic programs in white adipose tissue (“browning”), including mitochondrial biogenesis and the expression of uncoupling protein 1 (UCP1), leading to mitochondrial heat production and energy expenditure.
Thursday, April 12, 2012
Seeing the whole reduces access to its parts.
The content of our conscious experience is automatically dictated by higher level stages of visual processing, which are associated with the representation of more abstract and meaningful interpretations. Poljac et. al. show that the ability to form a more abstract representation of a given visual input (in terms of a particular object) does not simply mean that the details of this stimulus are not immediately or automatically accessible to conscious perception, but that these details become fundamentally less accessible. The whole decreases access to the parts.
The experiments used computer generated walking dot figures of humans, both upright (easy to form the gestalt as human walking), and upside-down (more difficult to form the gestalt), as well as random stationary or moving dots. The rates of changes in dot colors were not perceived as well in the upright walking figures which generated the clearest gestalts.
They suggest that the rapid extraction of a perceptual Gestalt, and the inaccessibility of the parts that make up that Gestalt, may in fact reflect two sides of the same coin whereby human vision provides only the most useful level of abstraction to conscious awareness. This whole point is explained very beautifully in Metzinger's book, "The Ego Tunnel." (I did a series of five daily posts on this post, starting on 6/30/09)
The experiments used computer generated walking dot figures of humans, both upright (easy to form the gestalt as human walking), and upside-down (more difficult to form the gestalt), as well as random stationary or moving dots. The rates of changes in dot colors were not perceived as well in the upright walking figures which generated the clearest gestalts.
They suggest that the rapid extraction of a perceptual Gestalt, and the inaccessibility of the parts that make up that Gestalt, may in fact reflect two sides of the same coin whereby human vision provides only the most useful level of abstraction to conscious awareness. This whole point is explained very beautifully in Metzinger's book, "The Ego Tunnel." (I did a series of five daily posts on this post, starting on 6/30/09)
Wednesday, April 11, 2012
Clothes can invade our body and brain...
Adam and Galinsky offer an interesting variant of studies on embodied cognition, a topic that MindBlog has frequently visited (35 postings, see left column) - showing that clothing can invade our body and brain, putting us into a different psychological state. After citing numerous studies of how clothes we wear have power over others, they do a discrete experiment to demonstrate a power of clothing over ourselves, specifically the power and accuracy of our attention:
We introduce the term “enclothed cognition” to describe the systematic influence that clothes have on the wearer's psychological processes. We offer a potentially unifying framework to integrate past findings and capture the diverse impact that clothes can have on the wearer by proposing that enclothed cognition involves the co-occurrence of two independent factors—the symbolic meaning of the clothes and the physical experience of wearing them. As a first test of our enclothed cognition perspective, the current research explored the effects of wearing a lab coat. A pretest found that a lab coat is generally associated with attentiveness and carefulness. We therefore predicted that wearing a lab coat would increase performance on attention-related tasks. In Experiment 1, physically wearing a lab coat increased selective attention compared to not wearing a lab coat. In Experiments 2 and 3, wearing a lab coat described as a doctor's coat increased sustained attention compared to wearing a lab coat described as a painter's coat, and compared to simply seeing or even identifying with a lab coat described as a doctor's coat. Thus, the current research suggests a basic principle of enclothed cognition—it depends on both the symbolic meaning and the physical experience of wearing the clothes.
Blog Categories:
embodied cognition,
social cognition
Tuesday, April 10, 2012
When two heads are worse than one - the cost of collaboration
An interesting bit in Psychological Science from Minson and Mueller, who demonstrate that joint decision making exacerbates rejection of outside information and lowers accuracy of the effort:
Prior investigators have asserted that certain group characteristics cause group members to disregard outside information and that this behavior leads to diminished performance. We demonstrate that the very process of making a judgment collaboratively rather than individually also contributes to such myopic underweighting of external viewpoints. Dyad members exposed to numerical judgments made by peers gave significantly less weight to those judgments than did individuals working alone. This difference in willingness to use peer input was mediated by the greater confidence that the dyad members reported in the accuracy of their own estimates. Furthermore, dyads were no better at judging the relative accuracy of their own estimates and the advisor’s estimates than individuals were. Our analyses demonstrate that, relative to individuals, dyads suffered an accuracy cost. Specifically, if dyad members had given as much weight to peer input as individuals working alone did, then their revised estimates would have been significantly more accurate.
Monday, April 09, 2012
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.
Blog Categories:
attention/perception,
social cognition
Friday, April 06, 2012
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.
Thursday, April 05, 2012
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).
Wednesday, April 04, 2012
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.
Tuesday, April 03, 2012
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.
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.
Monday, April 02, 2012
Innovation relies on the obscure.
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.
Friday, March 30, 2012
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.
Blog Categories:
attention/perception,
mirror neurons
Thursday, March 29, 2012
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:
From Saletan's review:
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.
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.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.
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.
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.
Blog Categories:
culture/politics,
evolutionary psychology,
human evolution,
morality
Wednesday, March 28, 2012
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.
Tuesday, March 27, 2012
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.
Monday, March 26, 2012
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.
Friday, March 23, 2012
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 18th 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.
..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 18th 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.
Thursday, March 22, 2012
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.
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