Thursday, December 31, 2015

Negative evaluation of counterstereotypical people by conservatives maintains their sense of certainty

Yet another study on differences in the psychology of conservative and liberal individuals:
People frequently use physical appearance stereotypes to categorize individuals when their group membership is not directly observable. Recent research indicates that political conservatives tend to use such stereotypes more than liberals do because they express a greater desire for certainty and order. In the present research, we found that conservatives were also more likely to negatively evaluate and distribute fewer economic resources to people who deviate from the stereotypes of their group. This occurred for people belonging to both preexisting and novel groups, regardless of whether the stereotypes were real or experimentally fabricated. Critically, conservatives only negatively evaluated counterstereotypical people when the stereotypes were functional—that is, when they expected that they would need to use the stereotypes at a later point to categorize individuals into groups. Moreover, increasing liberals’ desire for certainty led them to negatively evaluate counterstereotypical people just like conservatives did. Thus, conservatives are not only more likely to use stereotypes than are liberals, but are especially likely to negatively evaluate counterstereotypical people to organize the social world with greater certainty.

Wednesday, December 30, 2015

Dorsal and Ventral Right Brain Pathways for Prosody

Sammler et al. show that analysis of the emotional content, or vocal tone, of our speech is processed in dorsal and ventral streams of the right hemisphere much as phonology, syntax, and semantics are processed by dorsal and ventral streams of the left hemisphere:
Our vocal tone—the prosody—contributes a lot to the meaning of speech beyond the actual words. Indeed, the hesitant tone of a “yes” may be more telling than its affirmative lexical meaning. The human brain contains dorsal and ventral processing streams in the left hemisphere that underlie core linguistic abilities such as phonology, syntax, and semantics. Whether or not prosody — a reportedly right-hemispheric faculty — involves analogous processing streams is a matter of debate. Functional connectivity studies on prosody leave no doubt about the existence of such streams, but opinions diverge on whether information travels along dorsal or ventral pathways. Here we show, with a novel paradigm using audio morphing combined with multimodal neuroimaging and brain stimulation, that prosody perception takes dual routes along dorsal and ventral pathways in the right hemisphere. In experiment 1, categorization of speech stimuli that gradually varied in their prosodic pitch contour (between statement and question) involved (1) an auditory ventral pathway along the superior temporal lobe and (2) auditory-motor dorsal pathways connecting posterior temporal and inferior frontal/premotor areas. In experiment 2, inhibitory stimulation of right premotor cortex as a key node of the dorsal stream decreased participants’ performance in prosody categorization, arguing for a motor involvement in prosody perception. These data draw a dual-stream picture of prosodic processing that parallels the established left-hemispheric multi-stream architecture of language, but with relative rightward asymmetry.

Tuesday, December 29, 2015

Brain mitochondria function links anxiety with social subordination.

Hollis et al. make the fascinating observation that position in the social hierarchy of rats (dominant versus submissive) can be enhanced or diminished by stimulating or inhibiting energy metabolism of mitochondria in the nucleus accumbens, a brain region that regulates motivation and depression. It is interesting that several of the human dietary supplements that can be purchased from websites promoting brain rejuvenation contain stimulators of mitochondrial function. (I have noted one of these in a previous post.)
Dominance hierarchies are integral aspects of social groups, yet whether personality traits may predispose individuals to a particular rank remains unclear. Here we show that trait anxiety directly influences social dominance in male outbred rats and identify an important mediating role for mitochondrial function in the nucleus accumbens. High-anxious animals that are prone to become subordinate during a social encounter with a low-anxious rat exhibit reduced mitochondrial complex I and II proteins and respiratory capacity as well as decreased ATP and increased ROS production in the nucleus accumbens. A causal link for these findings is indicated by pharmacological approaches. In a dyadic contest between anxiety-matched animals, microinfusion of specific mitochondrial complex I or II inhibitors into the nucleus accumbens reduced social rank, mimicking the low probability to become dominant observed in high-anxious animals. Conversely, intraaccumbal infusion of nicotinamide, an amide form of vitamin B3 known to enhance brain energy metabolism, prevented the development of a subordinate status in high-anxious individuals. We conclude that mitochondrial function in the nucleus accumbens is crucial for social hierarchy establishment and is critically involved in the low social competitiveness associated with high anxiety. Our findings highlight a key role for brain energy metabolism in social behavior and point to mitochondrial function in the nucleus accumbens as a potential marker and avenue of treatment for anxiety-related social disorders.

Monday, December 28, 2015

Socioeconomic status, inflammatory reactivity, and social support.

Interesting work from John-Henderson et al., who suggest that social support is more effective in damping stress responses in people having childhoods with low socioeconomic status than in people with high childhood socioeconomic status.:
Low socioeconomic status (SES) during childhood confers risk for adverse health in adulthood. Accumulating evidence suggests that this may be due, in part, to the association between lower childhood SES and higher levels of pro-inflammatory cytokines. Drawing from literature showing that low childhood SES predicts exaggerated physiological reactivity to stressors and that lower SES is associated with a more communal, socially attuned orientation, we hypothesized that inflammatory reactivity would be more greatly affected by cues of social support among individuals whose childhood SES was low than among those whose childhood SES was high. In two studies, we found that individuals with lower subjective childhood SES exhibited greater reductions in pro-inflammatory cytokine reactivity to a stressor in the presence of a supportive figure (relative to conditions with an unsupportive or neutral figure). These effects were independent of current SES. This work helps illuminate SES-based differences in inflammatory reactivity to stressors, particularly among individuals whose childhood SES was low.

Friday, December 25, 2015

The need for affiliation - communities of kindness

I belong to the Gay Men's Chorus of South Florida, which completed a series of five Christmas season concerts over the past two weeks. Singing in these performances, and doing a piano duet accompaniment for one of the pieces, I was exhausted for several days. Being in the chorus reminds me of church and boy scout groups of my youth. It is a communal setting where there is a sense of family, laughter, love and community. I am struck by parallels with Mark Oppenheimer's description of another secular equivalent to church communities, the CrossFit gym movement.
A for-profit gym franchise founded in 2000 that now has 13,000 licensed operators serving at least two million exercisers, CrossFit — like television, sports fandom and health fads — has become the focus of study by researchers trying to pinpoint what constitutes religiosity in America.
Members speak about their "box," or gym.. others might speak about a church or synagogue community. The same is true of some 12-step program members, and devoted college-football fans. In an increasingly secular America, all sorts of activities and subcultures provide the meaning that in the past, at least as we imagine it, religious communities did.
The article outlines several parallels between CrossFit and religious communities. From one member:
What really struck us was the way in which people were bringing their kids to their box...or the way different workouts of the day were named after soldiers who had died in battle. So there’s all of these things you would expect to see in a church — remembering the dead through some sort of ritual, and intergenerational community.
In a similar vein, David Brooks writes about educational communities of character. He cites a number of examples of secondary school settings that emphasize kindness, respect, and responsibility in binding together a learning community.

Thursday, December 24, 2015

Empathy is a choice, and can be trained.

I want to pass on some clips from a review by Cameron et al. that summarizes, and has links to, a number of studies that deal our ability to share the experiences of others.
While a single crying child or injured puppy tugs at our heartstrings, large numbers of suffering people, as in epidemics, earthquakes and genocides, do not inspire a comparable reaction...Not only does empathy seem to fail when it is needed most, but it also appears to play favorites. Recent studies have shown that our empathy is dampened or constrained when it comes to people of different races, nationalities or creeds. These results suggest that empathy is a limited resource, like a fossil fuel, which we cannot extend indefinitely or to everyone.
While we concede that the exercise of empathy is, in practice, often far too limited in scope, we dispute the idea that this shortcoming is inherent, a permanent flaw in the emotion itself. Inspired by a competing body of recent research, we believe that empathy is a choice that we make whether to extend ourselves to of us, Daryl Cameron, along with the psychologist Keith Payne, conducted an experiment to see if ...motivational factors could explain why we seem more empathetic to single victims than to large numbers of them.
Participants in this study read about either one or eight child refugees from the Darfur region of Sudan. Half of the participants were led to expect that they would be asked to make a donation to the refugee or refugees, whereas the other half were not. When there was no financial cost involved in feeling empathy, people felt more empathy for the eight children than for the one child, reversing the usual bias. If insensitivity to mass suffering stemmed from an intrinsic limit to empathy, such financial factors shouldn’t have made a difference.
Likewise, in another recent study, the psychologists Karina Schumann, Jamil Zaki and Carol S. Dweck found that when people learned that empathy was a skill that could be improved — as opposed to a fixed personality trait — they engaged in more effort to experience empathy for racial groups other than their own. Empathy for people unlike us can be expanded, it seems, just by modifying our views about empathy.

Wednesday, December 23, 2015

Male and female brains do not constitute two distinct categories.

From Zoel et al.: Significance
Sex/gender differences in the brain are of high social interest because their presence is typically assumed to prove that humans belong to two distinct categories not only in terms of their genitalia, and thus justify differential treatment of males and females. Here we show that, although there are sex/gender differences in brain and behavior, humans and human brains are comprised of unique “mosaics” of features, some more common in females compared with males, some more common in males compared with females, and some common in both females and males. Our results demonstrate that regardless of the cause of observed sex/gender differences in brain and behavior (nature or nurture), human brains cannot be categorized into two distinct classes: male brain/female brain.
Whereas a categorical difference in the genitals has always been acknowledged, the question of how far these categories extend into human biology is still not resolved. Documented sex/gender differences in the brain are often taken as support of a sexually dimorphic view of human brains (“female brain” or “male brain”). However, such a distinction would be possible only if sex/gender differences in brain features were highly dimorphic (i.e., little overlap between the forms of these features in males and females) and internally consistent (i.e., a brain has only “male” or only “female” features). Here, analysis of MRIs of more than 1,400 human brains from four datasets reveals extensive overlap between the distributions of females and males for all gray matter, white matter, and connections assessed. Moreover, analyses of internal consistency reveal that brains with features that are consistently at one end of the “maleness-femaleness” continuum are rare. Rather, most brains are comprised of unique “mosaics” of features, some more common in females compared with males, some more common in males compared with females, and some common in both females and males. Our findings are robust across sample, age, type of MRI, and method of analysis. These findings are corroborated by a similar analysis of personality traits, attitudes, interests, and behaviors of more than 5,500 individuals, which reveals that internal consistency is extremely rare. Our study demonstrates that, although there are sex/gender differences in the brain, human brains do not belong to one of two distinct categories: male brain/female brain.

Tuesday, December 22, 2015

Good news for the grumpy.

A dogma of the self-help and happiness industries is that unhappiness decreases health and longevity. Happy people are supposed to live longer. Not so, it turns out, according to a British study published in The Lancet that followed one million middle-aged women in Britan for 10 years. Previous work may have confused cause and effect, suggesting that unhappiness made people ill, when it was actually the other way around. Bottom line from the article:
In middle-aged women, poor health can cause unhappiness. After allowing for this association and adjusting for potential confounders, happiness and related measures of wellbeing do not appear to have any direct effect on mortality.

Monday, December 21, 2015

Loneliness hurts.

Reynolds points to an article by Cacioppo et. al., who contribute to a special issue of Cortex magazine on Neuro-cognitive mechanisms of social interactions. From her review:
For early humans, being alone was no way to live. Those on the tribe’s periphery faced increased risks of starvation, predation and early death. And so humans (like other communal creatures) evolved what seem to be specific biological reactions to social threats. A social animal that feels itself to be isolated from its kind begins to behave nervously and experiences unhealthy physiological responses. The body produces more stress-­related biochemicals, leading to inflammation and a reduced ability to fight viral infections. These adaptations might help explain why many chronically lonely people have an overabundance of stress-­related cells and weakened immune systems. But how they see the world — how loneliness affects their thinking — may be just as consequential to their health.
The abstract of the Cacioppo et. al. article, which finds that lonely people become inadvertently hypervigilant to social threats, which makes the loneliness worse:
Being on the social perimeter is not only sad, it is dangerous. Our evolutionary model of the effects of perceived social isolation (loneliness) on the brain as well as a growing body of behavioral research suggests that loneliness promotes short-term self-preservation, including an increased implicit vigilance for social, in contrast to nonsocial, threats. However, this hypothesis has not been tested previously in a neuroimaging study. We therefore used high density EEG and a social Stroop interference task to test the hypothesis that implicit attention to negative social, in contrast to nonsocial, Words in the Stroop task differs between individuals high versus low in loneliness and to investigate the brain dynamics of implicit processing for negative social (vs nonsocial) stimuli in lonely individuals, compared to nonlonely individuals (N = 70). The present study provides the first evidence that negative social stimuli are differentiated from negative nonsocial stimuli more quickly in the lonely than nonlonely brains. Given the timing of this differentiation in the brain and the fact that participants were performing a Stroop task, these results also suggest that these differences reflect implicit rather than explicit attentional differences between lonely and nonlonely individuals. Source estimates were performed for purposes of hypothesis generation regarding underlying neural mechanisms, and the results implicated the neural circuits reminiscent of orienting and executive control aspects of attention as contributing to these differences. Together, the results are in accord with the evolutionary model of loneliness.

Friday, December 18, 2015

A special issue of Science Magazine on aging.

You can see titles and abstracts of articles here. And, I want to pass on a section of one of the articles, “Healthy aging: The ultimate preventative medicine,” that lists interventions to delay aging that seem promising.

Abstract: Age is the greatest risk factor for nearly every major cause of mortality in developed nations. Despite this, most biomedical research focuses on individual disease processes without much consideration for the relationships between aging and disease. Recent discoveries in the field of geroscience, which aims to explain biological mechanisms of aging, have provided insights into molecular processes that underlie biological aging and, perhaps more importantly, potential interventions to delay aging and promote healthy longevity. Here we describe some of these advances, along with efforts to move geroscience from the bench to the clinic. We also propose that greater emphasis should be placed on research into basic aging processes, because interventions that slow aging will have a greater effect on quality of life compared with disease-specific approaches.  

Geroscience interventions with translational potential.

Dietary restriction: Dietary restriction (DR) is the most studied intervention for delaying aging. Although not universally effective, a majority of studies have documented significant increases in both life span and health span when DR is applied in laboratory models, including nonhuman primates. Limited studies also indicate important health benefits, including reversal of disease risk factors, in people who practice DR. Although DR is not a viable translational approach at the population level, research in this area has incited the search for alternative dietary modifications (e.g., low-protein diets) or small-molecule DR mimetics (e.g., mTOR inhibitors, see below) that can provide the health benefits of DR without requiring reduced food consumption.

Exercise: A large body of literature provides evidence that the health benefits of exercise are consistent with the enhancement of health span. However, poor compliance, especially in the elderly population, makes this intervention challenging to apply. Thus, there is high interest in developing pharmacologic interventions that would synergize with lower levels of exercise.

mTOR inhibitors: Rapamycin extends life span and promotes health span in mice, as well as in simpler organisms. Treatment beginning late in life is sufficient to extend life span, reverse cardiac decline, and improve immune function in mice. A recent study also reported that a rapamycin derivative significantly boosts immune function in elderly people .

Metformin and acarbose: Metformin and acarbose are widely used antidiabetes drugs. Metformin improves health span in mice and may slightly extend life span, whereas acarbose markedly extends life span in male mice and modestly extends life span in female mice. In a nonrandomized retrospective analysis, diabetic patients taking metformin have reduced mortality compared with diabetic patients not receiving metformin, and they may live longer than nondiabetics not receiving metformin.

NAD precursors and sirtuin activators: Nicotinamide adenine dinucleotide (NAD) precursors such as nicotinamide riboside and nicotinamide mononucleotide have been reported to improve health span in mouse models of muscle aging and cognitive decline. The mechanism of action is not clear, but it may involve activation of sirtuin NAD-dependent protein deacetylases, along with enhanced mitochondrial function. Other, possibly more specific, sirtuin activators also improve health span and slightly extend life span in mice.

Modifiers of senescence and telomere dysfunction:Senescent cells accumulate during aging and secrete factors that promote inflammation and cancer. Telomere dysfunction is a major cause of cell senescence, and strategies to enhance telomerase function offer promise for improving health span, although the possibility of increased cancer risk must be addressed. Likewise, genetic and pharmacological strategies to target and kill senescent cells enhance both life span and markers of health in short-lived mice with high levels of senescent cells.

Hormonal and circulating factors: Age-related changes in important hormones (including sex-steroids, growth hormone, and insulin-like growth factor 1) are well documented; however, the risks and benefits of hormone supplementation in aging remain largely controversial.  Heterochronic parabiosis experiments in which the circulatory system of an aged mouse is shared with that of a young mouse suggest that additional, more subtle humoral factors affect age-associated declines in several tissues, including the brain, muscle, liver, and heart. Some progress has been made toward defining these factors, and an effort is under way to determine whether transfusion of young plasma can delay Alzheimer’s disease.

Mitochondrial-targeted therapeutics: Mitochondrial dysfunction is a major contributor to aging and age-related diseases, although the mechanisms are more complex than initially suggested by the Harman’s free radical theory of aging. Attention is now being directed to interventions that augment mitochondrial function, energetics, and biogenesis, including mitochondrial-targeted antioxidants and NAD precursors.

Thursday, December 17, 2015

Exercise helps your brain rewire.

Our brains are most capable of changing in response to experience when we are young, then this ability abruptly declines into adulthood. Lunghi and Sale do an interesting experiment showing how the plasticity that does remain can be enhanced by exercise. Covering one eye and watching a movie while relaxing in a chair boosts brain responses to the deprived eye. If study participants instead watched the movie while alternating 10 min. intervals of rest and cycling on a stationary bike, this enhancement of the deprived eye became much larger. A figure, followed by their abstract:

Brain plasticity, defined as the capability of cerebral neurons to change in response to experience, is fundamental for behavioral adaptability, learning, memory, functional development, and neural repair. The visual cortex is a widely used model for studying neuroplasticity and the underlying mechanisms. Plasticity is maximal in early development, within the so-called critical period, while its levels abruptly decline in adulthood. Recent studies, however, have revealed a significant residual plastic potential of the adult visual cortex by showing that, in adult humans, short-term monocular deprivation alters ocular dominance by homeostatically boosting responses to the deprived eye. In animal models, a reopening of critical period plasticity in the adult primary visual cortex has been obtained by a variety of environmental manipulations, such as dark exposure, or environmental enrichment, together with its critical component of enhanced physical exercise. Among these non-invasive procedures, physical exercise emerges as particularly interesting for its potential of application to clinics, though there has been a lack of experimental evidence available that physical exercise actually promotes visual plasticity in humans. Here we report that short-term homeostatic plasticity of the adult human visual cortex induced by transient monocular deprivation is potently boosted by moderate levels of voluntary physical activity. These findings could have a bearing in orienting future research in the field of physical activity application to clinical research.

Wednesday, December 16, 2015

Why doesn't economic growth lead to more happiness?

This is the Easterlin paradox, which I have mentioned in a previous post. Oishi and Kesebir now do an interesting analysis showing that economic growth is not associated with increases in happiness when it is accompanied by growing income inequality.:
One of the most puzzling social science findings in the past half century is the Easterlin paradox: Economic growth within a country does not always translate into an increase in happiness. We provide evidence that this paradox can be partly explained by income inequality. In two different data sets covering 34 countries, economic growth was not associated with increases in happiness when it was accompanied by growing income inequality. Earlier instances of the Easterlin paradox (i.e., economic growth not being associated with increasing happiness) can thus be explained by the frequent concurrence of economic growth and growing income inequality. These findings suggest that a more even distribution of growth in national wealth may be a precondition for raising nationwide happiness.

Tuesday, December 15, 2015

Modest exercise gives maximum health benefits.

Gretchen Reynolds points to a study in the Mayo Clinic Proceedings that reviews studies published in PubMed since 2000 that included at least 500 runners and 5-year follow-up to analyze the relationship between running, cardiovascular disease, and all-cause mortality. The optimal dose of running required for protection is surprisingly small. Running for 20-30 minutes twice per week appears to give maximum benefits. Three to four times the duration of walking is needed to achieve the same benefits.

Monday, December 14, 2015

Coffee consumption correlates with lower risk of dying.

From Nicholas Bakalar, who notes a study showing that people who drink more coffee have a reduced risk of death - a correlation (not necessarily a cause): 
Researchers followed more than 200,000 doctors and nurses for up to 30 years. The participants had periodic physical examinations and completed questionnaires on diet and behavior, including their coffee habits. The study is in Circulation.  
Compared with abstainers, nonsmokers who drank a cup of coffee a day had a 6 percent reduced risk of death, one to three cups an 8 percent reduced risk, three to five cups a 15 percent reduced risk, and more than five cups a 12 percent reduced risk. There was little difference whether they drank caffeinated or decaffeinated coffee. The association persisted after controlling for age, alcohol consumption, B.M.I. and other health and diet factors.  
Coffee drinking was linked to a reduced risk of death from heart disease, stroke, diabetes, neurological diseases and suicide, although not from cancer.

Friday, December 11, 2015

Exercise enhances frontal brain lateralization characteristic of younger brains.

As we age beyond 40 years or so, mental tasks that require attention, problem solving, decision-making and other types of high-level thinking become less localized to one of our frontal lobes and expand to engage both hemispheres of our prefrontal cortex. This represents a general reorganization and weakening of our brains' function with age. Hyodo et. al. show in a group of Japanese men with no signs of dementia, between between 64 and 75 years old, that increased aerobic fitness correlates with the increased lateralization during task performance characteristic of younger brains. Here are their summaries:

• Association among fitness, brain activation, and cognitive function was examined. 
• Frontal laterality during Stroop task in older men was assessed by fNIRS. 
• We found the association between ventilatory threshold and Stroop performance. 
• The association was mediated by the lateralized prefrontal activation.
Previous studies have shown that higher aerobic fitness is related to higher cognitive function and higher task-related prefrontal activation in older adults. However, a holistic picture of these factors has yet to be presented. As a typical age-related change of brain activation, less lateralized activity in the prefrontal cortex during cognitive tasks has been observed in various neuroimaging studies. Thus, this study aimed to reveal the relationship between aerobic fitness, cognitive function, and frontal lateralization. Sixty male older adults each performed a submaximal incremental exercise test to determine their oxygen intake at ventilatory threshold (VT) in order to index their aerobic fitness. They performed a color–word Stroop task while prefrontal activation was monitored using functional near infrared spectroscopy. As an index of cognitive function, Stroop interference time was analyzed. Partial correlation analyses revealed significant correlations among higher VT, shorter Stroop interference time and greater left-lateralized dorsolateral prefrontal cortex (DLPFC) activation when adjusting for education. Moreover, mediation analyses showed that left-lateralized DLPFC activation significantly mediated the association between VT and Stroop interference time. These results suggest that higher aerobic fitness is associated with cognitive function via lateralized frontal activation in older adults.

Thursday, December 10, 2015

Mindfulness meditation and pain reduction.

An interesting analysis from Zeidan et al.:

Recent findings have demonstrated that mindfulness meditation significantly reduces pain. Given that the “gold standard” for evaluating the efficacy of behavioral interventions is based on appropriate placebo comparisons, it is imperative that we establish whether there is an effect supporting meditation-related pain relief above and beyond the effects of placebo. Here, we provide novel evidence demonstrating that mindfulness meditation produces greater pain relief and employs distinct neural mechanisms than placebo cream and sham mindfulness meditation. Specifically, mindfulness meditation-induced pain relief activated higher-order brain regions, including the orbitofrontal and cingulate cortices. In contrast, placebo analgesia was associated with decreased pain-related brain activation. These findings demonstrate that mindfulness meditation reduces pain through unique mechanisms and may foster greater acceptance of meditation as an adjunct pain therapy.
Mindfulness meditation reduces pain in experimental and clinical settings. However, it remains unknown whether mindfulness meditation engages pain-relieving mechanisms other than those associated with the placebo effect (e.g., conditioning, psychosocial context, beliefs). To determine whether the analgesic mechanisms of mindfulness meditation are different from placebo, we randomly assigned 75 healthy, human volunteers to 4 d of the following: (1) mindfulness meditation, (2) placebo conditioning, (3) sham mindfulness meditation, or (4) book-listening control intervention. We assessed intervention efficacy using psychophysical evaluation of experimental pain and functional neuroimaging. Importantly, all cognitive manipulations (i.e., mindfulness meditation, placebo conditioning, sham mindfulness meditation) significantly attenuated pain intensity and unpleasantness ratings when compared to rest and the control condition (p less than 0.05). Mindfulness meditation reduced pain intensity (p = 0.032) and pain unpleasantness (p less than 0.001) ratings more than placebo analgesia. Mindfulness meditation also reduced pain intensity (p = 0.030) and pain unpleasantness (p = 0.043) ratings more than sham mindfulness meditation. Mindfulness-meditation-related pain relief was associated with greater activation in brain regions associated with the cognitive modulation of pain, including the orbitofrontal, subgenual anterior cingulate, and anterior insular cortex. In contrast, placebo analgesia was associated with activation of the dorsolateral prefrontal cortex and deactivation of sensory processing regions (secondary somatosensory cortex). Sham mindfulness meditation-induced analgesia was not correlated with significant neural activity, but rather by greater reductions in respiration rate. This study is the first to demonstrate that mindfulness-related pain relief is mechanistically distinct from placebo analgesia. The elucidation of this distinction confirms the existence of multiple, cognitively driven, supraspinal mechanisms for pain modulation.
Note: In the sham mindfulness training, conditions were identical to mindfulness training session, but subjects were told just to close their eyes and take a deep breath 'as we sit here in meditation' every 2-3 min. They were not given the specific mindfulness-based instructions to pay attention to the breath, acknowledge arising thoughts, feelings, and/or emotion without judgment or emotional reaction, and simply return attention back to the breath. In the placebo training/conditioning sessions, participants were told they were participating in the trial of a new topical local anesthetic (actually petrolatum jelly) being tested for reducing pain after multiple applications. In all of the conditions, pain was induced by local heating of the skin.

Wednesday, December 09, 2015

Gender bias in the attribution of creativity

Slightly edited abstract from Proudfoot et al., who provide further examples of gender discrimination:
We propose that the propensity to think creatively tends to be associated with independence and self-direction—qualities generally ascribed to men—so that men are often perceived to be more creative than women. In a first study, we found that “outside the box” creativity is more strongly associated with stereotypically masculine characteristics (e.g., daring and self-reliance) than with stereotypically feminine characteristics (e.g., cooperativeness and supportiveness.) A second study found that a man is ascribed more creativity than a woman when they produce identical output. A third study analyzed archival data, and found that men’s ideas are evaluated as more ingenious than women’s ideas. Study four found that female executives are stereotyped as less innovative than their male counterparts when evaluated by their supervisors. Finally, we observed that stereotypically masculine behavior enhances a man’s perceived creativity, whereas identical behavior does not enhance a woman’s perceived creativity. This boost in men’s perceived creativity is mediated by attributions of agency, not competence, and predicts perceptions of reward deservingness.

Tuesday, December 08, 2015

Lower leg power predicts cognitive aging.

Gretchen Reynolds points to a study of 162 healthy female twin pairs, some identical, and some not, who 10 years previously had completed extensive examinations of their thinking and memory abilities, as well as measurements of their leg-muscle power.
...those who had had the sturdiest legs a decade ago showed the least fall-off in thinking skills, even when the scientists controlled for such factors as fatty diets, high blood pressure and shaky blood-sugar control...a muscularly powerful twin now performed about 18 percent better on memory and other cognitive tests than her weaker the brain imaging of the identical twins, if one genetically identical twin had had sturdier legs than the other at the start of the study, she now displayed significantly more brain volume and fewer “empty spaces in the brain” than her weaker sister.
Keep in mind the 'this is only one study' caution. It involved only a single analysis of the brain health of middle-aged female twins. However, it is a plausible result, because it is known that exercise causes muscles to release brain growth factors, and sturdier muscles might be expected to release more.

Monday, December 07, 2015

Racial bias and time perception.

From Moskowitz et al.:
Arousal is known to shape time perception, and heightened arousal causes one to perceive that time has slowed (i.e., a given length of time feels longer than it actually is). The current experiments illustrate that among White people who experience arousal when contemplating race (specifically those for whom appearing biased is an ongoing concern), time perception slows when they observe faces of Black men. We asked participants to judge the duration of presentation for faces of White and Black men (shown for periods ranging from 300 to 1,200 ms) relative to a standard duration of 600 ms. Evidence of bias emerged when White participants concerned with bias saw faces of Black men (e.g., durations of less than 600 ms were perceived as being greater than 600 ms). The current findings have implications for intergroup interactions in which timing is essential—for example, length of job interviews, police officers’ perception of the length of an encounter and when force should be initiated, and doctors’ perception of the length of medical encounters. Racially biased time perception is a new form of implicit bias, one exerted at the perceptual level.

Friday, December 04, 2015

Cultural specificity of human fairness.

Blake et al. do an interesting experiment on how sensitive children are to inequality. They asked one child in a pair or to accept or reject an offer of Skittles on behalf of both of them. Between ages 4 and 15 offers that were equal for both children were accepted, but older children often refected offers that would provide more Skittles to their partner. The age at which children started rejecting such offers varied across the seven countries studied (Canada, India, Mexico, Peru, Senegal, Uganda, USA) suggesting different times for development of a sense of fairness. In three countries—the United States, Canada, and Uganda—some older children also rejected offers that were unfair to their partner.
A sense of fairness plays a critical role in supporting human cooperation. Adult norms of fair resource sharing vary widely across societies, suggesting that culture shapes the acquisition of fairness behaviour during childhood. Here we examine how fairness behaviour develops in children from seven diverse societies, testing children from 4 to 15 years of age (n = 866 pairs) in a standardized resource decision task. We measured two key aspects of fairness decisions: disadvantageous inequity aversion (peer receives more than self) and advantageous inequity aversion (self receives more than a peer). We show that disadvantageous inequity aversion emerged across all populations by middle childhood. By contrast, advantageous inequity aversion was more variable, emerging in three populations and only later in development. We discuss these findings in relation to questions about the universality and cultural specificity of human fairness.

Thursday, December 03, 2015

The evolution of music from emotional signals

I want to pass on the slightly edited abstract of a recent article on the evolutionary origins of music, "Music evolution and neuroscience," in Progress in Brain Research, written by my Univ. of Wisconsin colleague Charles Snowdon.
There have been many attempts to discuss the evolutionary origins of music. We review theories of music origins and take the perspective that music is originally derived from emotional signals in both humans and animals. An evolutionary approach has two components: First, is music adaptive? How does it improve reproductive success? Second, what, if any, are the phylogenetic origins of music? Can we find evidence of music in other species? We show that music has adaptive value through emotional contagion, social cohesion, and improved well-being. We trace the roots of music through the emotional signals of other species suggesting that the emotional aspects of music have a long evolutionary history. We show how music and speech are closely interlinked with the musical aspects of speech conveying emotional information. We describe acoustic structures that communicate emotion in music and present evidence that these emotional features are widespread among humans and also function to induce emotions in animals. Similar acoustic structures are present in the emotional signals of nonhuman animals. We conclude with a discussion of music designed specifically to induce emotional states in animals, both cotton top tamarin monkeys and domestic cats.

Wednesday, December 02, 2015

Increased false-memory susceptibility after mindfulness meditation

From Wilson et al.:
The effect of mindfulness meditation on false-memory susceptibility was examined in three experiments. Because mindfulness meditation encourages judgment-free thoughts and feelings, we predicted that participants in the mindfulness condition would be especially likely to form false memories. In two experiments, participants were randomly assigned to either a mindfulness induction, in which they were instructed to focus attention on their breathing, or a mind-wandering induction, in which they were instructed to think about whatever came to mind. The overall number of words from the Deese-Roediger-McDermott paradigm that were correctly recalled did not differ between conditions. However, participants in the mindfulness condition were significantly more likely to report critical nonstudied items than participants in the control condition. In a third experiment, which tested recognition and used a reality-monitoring paradigm, participants had reduced reality-monitoring accuracy after completing the mindfulness induction. These results demonstrate a potential unintended consequence of mindfulness meditation in which memories become less reliable.

Tuesday, December 01, 2015

Religiousness decreases children’s altruistic behaviors.

Decety et al. challenge the view that religiosity facilitates prosocial behavior.:

•Family religious identification decreases children’s altruistic behaviors
•Religiousness predicts parent-reported child sensitivity to injustices and empathy
•Children from religious households are harsher in their punitive tendencies 
Prosocial behaviors are ubiquitous across societies. They emerge early in ontogeny and are shaped by interactions between genes and culture. Over the course of middle childhood, sharing approaches equality in distribution. Since 5.8 billion humans, representing 84% of the worldwide population, identify as religious, religion is arguably one prevalent facet of culture that influences the development and expression of prosociality. While it is generally accepted that religion contours people’s moral judgments and prosocial behavior, the relation between religiosity and morality is a contentious one. Here, we assessed altruism and third-party evaluation of scenarios depicting interpersonal harm in 1,170 children aged between 5 and 12 years in six countries (Canada, China, Jordan, Turkey, USA, and South Africa), the religiousness of their household, and parent-reported child empathy and sensitivity to justice. Across all countries, parents in religious households reported that their children expressed more empathy and sensitivity for justice in everyday life than non-religious parents. However, religiousness was inversely predictive of children’s altruism and positively correlated with their punitive tendencies. Together these results reveal the similarity across countries in how religion negatively influences children’s altruism, challenging the view that religiosity facilitates prosocial behavior.

Monday, November 30, 2015

The effects of birth order on personality.

Rohrer et. al. issue a new installment on the perennial question of how our birth order influences us, with a study showing higher intelligence in firstborns,  but no birth-order effects on extraversion, emotional stability, agreeableness, conscientiousness, or imagination.:

The question of whether a person’s position among siblings has a lasting impact on that person’s life course has fascinated both the scientific community and the general public for >100 years. By combining large datasets from three national panels, we confirmed the effect that firstborns score higher on objectively measured intelligence and additionally found a similar effect on self-reported intellect. However, we found no birth-order effects on extraversion, emotional stability, agreeableness, conscientiousness, or imagination. This finding contradicts lay beliefs and prominent scientific theories alike and indicates that the development of personality is less determined by the role within the family of origin than previously thought. 
This study examined the long-standing question of whether a person’s position among siblings has a lasting impact on that person’s life course. Empirical research on the relation between birth order and intelligence has convincingly documented that performances on psychometric intelligence tests decline slightly from firstborns to later-borns. By contrast, the search for birth-order effects on personality has not yet resulted in conclusive findings. We used data from three large national panels from the United States (n = 5,240), Great Britain (n = 4,489), and Germany (n = 10,457) to resolve this open research question. This database allowed us to identify even very small effects of birth order on personality with sufficiently high statistical power and to investigate whether effects emerge across different samples. We furthermore used two different analytical strategies by comparing siblings with different birth-order positions (i) within the same family (within-family design) and (ii) between different families (between-family design). In our analyses, we confirmed the expected birth-order effect on intelligence. We also observed a significant decline of a 10th of a SD in self-reported intellect with increasing birth-order position, and this effect persisted after controlling for objectively measured intelligence. Most important, however, we consistently found no birth-order effects on extraversion, emotional stability, agreeableness, conscientiousness, or imagination. On the basis of the high statistical power and the consistent results across samples and analytical designs, we must conclude that birth order does not have a lasting effect on broad personality traits outside of the intellectual domain.

Friday, November 27, 2015

A picture show; and, Alzheimer's and the innate immune system

Our nervous and immune systems interact with each other at the same time they both interact with our environment. Cell magazine has put together a picture show that illustrates the beauty and complexity of these interactions. It accompanies special issues of Trends in Neuroscience and Trends in Immunology that deal with neuroimmunology in disease and in normal aging. Of special interest is a description of how releasing an inhibition of the innate immune system can allow phagocytes to clear the Aβ/β-amyloid of Alzheimer's disease from the brain.

Thursday, November 26, 2015

Online political communication: more than an echo chamber?

From Barbera et al.:
We estimated ideological preferences of 3.8 million Twitter users and, using a data set of nearly 150 million tweets concerning 12 political and nonpolitical issues, explored whether online communication resembles an “echo chamber” (as a result of selective exposure and ideological segregation) or a “national conversation.” We observed that information was exchanged primarily among individuals with similar ideological preferences in the case of political issues (e.g., 2012 presidential election, 2013 government shutdown) but not many other current events (e.g., 2013 Boston Marathon bombing, 2014 Super Bowl). Discussion of the Newtown shootings in 2012 reflected a dynamic process, beginning as a national conversation before transforming into a polarized exchange. With respect to both political and nonpolitical issues, liberals were more likely than conservatives to engage in cross-ideological dissemination; this is an important asymmetry with respect to the structure of communication that is consistent with psychological theory and research bearing on ideological differences in epistemic, existential, and relational motivation. Overall, we conclude that previous work may have overestimated the degree of ideological segregation in social-media usage.

Wednesday, November 25, 2015

Choosing to be grateful.

In a piece timed for Thanksgiving, Arthur Brooks does a nice job of fetching up and giving links to references to a number of interesting studies on the positive effects of gratitude on well-being. Arthur Brooks is a person who my knee-jerk liberal reflexes would dictate be discounted immediately, because he is head of the conservative American Enterprise Institute. However this former academic is one clever dude (Here is an Op-Ed piece on abundance. Other commentaries are found here.)

Musical expertise modulates the brain’s entrainment to music.

Yet another study, by Doelling and Poeppel, showing effects of musical training on the brain and supporting a role for cortical oscillatory activity in music perception and cognition.:

We demonstrate that cortical oscillatory activity in both low (less than 8 Hz) and high (15–30 Hz) frequencies is tightly coupled to behavioral performance in musical listening, in a bidirectional manner. In light of previous work on speech, we propose a framework in which the brain exploits the temporal regularities in music to accurately parse individual notes from the sound stream using lower frequencies (entrainment) and in higher frequencies to generate temporal and content-based predictions of subsequent note events associated with predictive models.
Recent studies establish that cortical oscillations track naturalistic speech in a remarkably faithful way. Here, we test whether such neural activity, particularly low-frequency (less than 8 Hz; delta–theta) oscillations, similarly entrain to music and whether experience modifies such a cortical phenomenon. Music of varying tempi was used to test entrainment at different rates. In three magnetoencephalography experiments, we recorded from nonmusicians, as well as musicians with varying years of experience. Recordings from nonmusicians demonstrate cortical entrainment that tracks musical stimuli over a typical range of tempi, but not at tempi below 1 note per second. Importantly, the observed entrainment correlates with performance on a concurrent pitch-related behavioral task. In contrast, the data from musicians show that entrainment is enhanced by years of musical training, at all presented tempi. This suggests a bidirectional relationship between behavior and cortical entrainment, a phenomenon that has not previously been reported. Additional analyses focus on responses in the beta range (∼15–30 Hz)—often linked to delta activity in the context of temporal predictions. Our findings provide evidence that the role of beta in temporal predictions scales to the complex hierarchical rhythms in natural music and enhances processing of musical content. This study builds on important findings on brainstem plasticity and represents a compelling demonstration that cortical neural entrainment is tightly coupled to both musical training and task performance, further supporting a role for cortical oscillatory activity in music perception and cognition.

Tuesday, November 24, 2015

Our bodies can sabotage our healthy behaviors..

I pass on an interesting chunk from Reynolds' review of work by Mansoubi et al. showing that people who use sit-to-stand workstations in their office compensate by reducing activity and increasing sitting outside of working hours, thus canceling out the effects of their virtuous exercise at the office.
...the human body and brain are funny. They often, and rather insidiously, undermine some of our best efforts to be healthier, in an attempt to maintain our physiological status quo. The result can be that we do not benefit as much as we’d hoped from changes to our lifestyles. When we slash calories to lose weight, for instance, our bodies often lower our metabolic rate, and our weight doesn’t budge much.

Similarly, studies of people who begin or greatly intensify an exercise program have shown that these exercisers often start sitting more during the hours when they are not working out, so that their overall daily energy expenditure doesn’t increase substantially and the number of hours that they spend sitting grows.

Monday, November 23, 2015

Wielding power increases testosterone in women.

Anders et al. provide evidence for a gender→testosterone pathway:

Human biology is typically studied within the framework of sex (evolved, innate factors) rather than gender (sociocultural factors), despite some attention to nature/nurture interactions. Testosterone is an exemplar of biology studied as natural difference: men’s higher testosterone is typically seen as an innate “sex” difference. However, our experiment demonstrates that gender-related social factors also matter, even for biological measures. Gender socialization may affect testosterone by encouraging men but not women toward behaviors that increase testosterone. This shows that research on human sex biology needs to account for gender socialization and that nurture, as well as nature, is salient to hormone physiology. Our paper provides a demonstration of a novel gender→testosterone pathway, opening up new avenues for studying gender biology.
Testosterone is typically understood to contribute to maleness and masculinity, although it also responds to behaviors such as competition. Competition is crucial to evolution and may increase testosterone but also is selectively discouraged for women and encouraged for men via gender norms. We conducted an experiment to test how gender norms might modulate testosterone as mediated by two possible gender→testosterone pathways. Using a novel experimental design, participants (trained actors) performed a specific type of competition (wielding power) in stereotypically masculine vs. feminine ways. We hypothesized in H1 (stereotyped behavior) that wielding power increases testosterone regardless of how it is performed, vs. H2 (stereotyped performance), that wielding power performed in masculine but not feminine ways increases testosterone. We found that wielding power increased testosterone in women compared with a control, regardless of whether it was performed in gender-stereotyped masculine or feminine ways. Results supported H1 over H2: stereotyped behavior but not performance modulated testosterone. These results also supported theory that competition modulates testosterone over masculinity. Our findings thus support a gender→testosterone pathway mediated by competitive behavior. Accordingly, cultural pushes for men to wield power and women to avoid doing so may partially explain, in addition to heritable factors, why testosterone levels tend to be higher in men than in women: A lifetime of gender socialization could contribute to “sex differences” in testosterone. Our experiment opens up new questions of gender→testosterone pathways, highlighting the potential of examining nature/nurture interactions and effects of socialization on human biology.

Friday, November 20, 2015

Flip-Flops in medical advice.

I want to forward readers some clips I've taken from a review by Zuger of a recent book "Ending Medical Reversal" by Prasad and Cifu. After glancing through the following you might want to also have a look a this article by Span on the over-treatment of older patients.
Prasad and Cifu... have set themselves the task of figuring out how often modern medicine reverses itself, analyzing why it happens, and suggesting ways to make it stop...[they] extrapolate from past reversals to conclude that about 40 percent of what we consider state-of-the-art health care is likely to turn out to be unhelpful or actually harmful.
Recent official flip-flops include habits of treating everything from lead poisoning to blood clots, from kidney stones to heart attacks. One reversal concerned an extremely common orthopedic procedure, the surgical repair of the meniscus in the knee, which turns out to be no more effective than physical therapy alone. The interested reader can plow through almost 150 disproved treatments in the book’s appendix.
What could make more sense, after all, than finding some cancers early, fixing a piece of torn cartilage, closing a hole in the heart, and propping open blood vessels that have become perilously narrow? And yet not one of these helpful interventions has been shown to make a difference in the health or survival of patients who obediently line up to have them done.
“Often the study of the study of how therapies should work is much more extensive and comes before the study of whether therapies do work,” the authors write. Thus a medical culture based on “should work” rather than “does work” is condemned to constantly correct itself when the science is finally evaluated for outcomes that matter.
To fix this constant backtracking would require nothing less than a revolution in how doctors are trained, with an emphasis on the proven and practical rather than the theoretical. (It would also require a second revolution in how doctors practice, with less prestige and remuneration for coming up with new ideas and more for validating old ones.)

Thursday, November 19, 2015

Divided we fall - putting social progress on par with prosperity

Laura Levis, in Harvard Magazine, describes work of Porter and Stern, who have developed a social progress index that:
...ranks 133 countries on multiple dimensions of social and environmental performance in three main categories: Basic Human Needs (food, water, shelter, safety); Foundations of Wellbeing (basic education, information, health, and a sustainable environment); and Opportunity (freedom of choice, freedom from discrimination, and access to higher education). Porter considers the index “the most comprehensive framework developed for measuring social progress, and the first to measure social progress independently of gross domestic product (GDP)."

The United States may rank sixth among countries in terms of GDP per capita, but its results on the Social Progress Index are lackluster. It is sixteenth overall in social progress: well below Canada, the United Kingdom, Germany, and Japan in several key areas, including citizens’ quality of life and provision of basic human needs. The nation ranks thirtieth in personal safety, forty-fifth in access to basic knowledge, sixty-eighth on health and wellness, and seventy-fourth in ecosystem sustainability. “We had a lot of firsts in social progress over the years in America,” Porter points out, “but we kind of lost our rhythm and our momentum.”
About 20 or 30 years ago, for reasons Porter says he cannot completely explain, the rate of progress in America began to slow down. As a society, he points out, Americans slowly became more divided, and important priorities such as healthcare, education, and politics suffered. “We had gridlock, whether it’s unions or whether it’s ideological differences, and—although we’ve made some big steps in certain areas of human rights like gay rights—if you think about the really core things like our education system and our health system, we’re just not moving,” he says. “I think our political system isn’t helping, because we’re all about political gains and blocking the other guy, rather than compromising and getting things done.”

Wednesday, November 18, 2015

A personal note, the Steinway B now in Fort Lauderdale - some Chopin

After a few tense moments,  my Steinway B is now moved from Wisconsin to Florida.

I've upgraded my video and audio recording equipment, finally got the bugs out of the process, and thought I would pass on my first test recording - of a Chopin Nocturne that I plan to play at a recital next February here in Fort Lauderdale.  The vers. 3 refers to the fact that this is the third recording of this piece that I have put on my YouTube channel.


Neuropolitics - reading the electorate's mind.

Members of our two major political parties increasingly seem to inhabit alternative realities that are utterly incomprehending of each other. How about reinforcing these bubbles with technology for feeding blocks of voters only what they want to hear? A NYTimes piece by Kevin Randall describes some really spooky new political tools: digital campaign signs that note the facial and emotional reactions of those watching their message and tally emotional reactions like happiness, surprise, anger, disgust, fear and sadness. This permits alteration of the message to elicit desired responses. Such devices have been used in Mexico, Poland, Turkey, and probably the U.S.
In Mexico, President Enrique Peña Nieto’s campaign and his party, the Institutional Revolutionary Party, or PRI, employed tools to measure voters’ brain waves, skin arousal, heart rates and facial expressions during the 2012 presidential campaign. More recently, the party has been using facial coding to help pick its best candidates, one consultant says. Some officials even speak openly about their embrace of neuropolitical techniques, and not just for campaigning, but for governing as well.
Neuromarketing consultants say they are conducting research like this in more than a dozen countries, including Argentina, Brazil, Costa Rica, El Salvador, Russia, Spain and, to a much lesser extent, the United States.
One neuromarketing firm says it has worked for a Hillary Rodham Clinton presidential campaign committee to help it improve its targeting and messages.
David Plouffe, President Obama’s former campaign manager, said the tools “would be new ground for political campaigns...The richness of this data compared to what is gathered today in testing ads or evaluating speeches and debates, which is the trusty old dial test and primitive qualitative methods, is hard to comprehend. It gets more to emotion, intensity and a more complex understanding of how people are reacting.”
Added note: Mexico's governing party, the PRI, has now said it will no longer employ the techniques described above.

Tuesday, November 17, 2015

The Brain with David Eagleman

I want to point MindBlog readers who aren't already aware of the David Eagleman PBS series on the brain to its description on the PBS website. The episodes can be viewed on mobile devices, in your web browser, etc. I found episode 4 "Why Do I Need You?," on our social brains, to be a very compelling one.

More evolution cartoons

I pass this on from a recent seminar presentation to the Chaos group at the Univ. of Wisconsin... There must be hundreds of cartoons that take a different tack on this sequence:

Monday, November 16, 2015

Good and bad stress in the Brain - The inverted U

I want to pass on a bit of commentary by Robert Sapolsky, in a special issue of Nature Neuroscience that focuses on stress, that presents a clear and lucid description of "good stress" and "bad stress." a large extent, the effects of stress in the brain form a nonlinear 'inverted-U' dose-response curve as a function of stressor severity: the transition from the complete absence of stress to mild stress causes an increase in endpoint X, the transition from mild-to-moderate stress causes endpoint X to plateau and the transition from moderate to more severe stress decreases endpoint X.
A classic example of the inverted-U is seen with the endpoint of synaptic plasticity in the hippocampus, where mild-to-moderate stressors, or exposure to glucocorticoid concentrations in the range evoked by such stressors, enhances primed burst potentiation, whereas more severe stressors or equivalent elevations of glucocorticoid concentrations do the opposite11. This example also demonstrates an elegant mechanism for generating such an inverted-U12. Specifically, the hippocampus contains ample quantities of receptors for glucocorticoids. These come in two classes. First, there are the high-affinity low-capacity mineralocorticoid receptors (MRs), which are mostly occupied under basal, non-stress conditions and in which occupancy increases to saturating levels with mild-to-moderate stressors. In contrast, there are the low-affinity, high-capacity glucocorticoid receptors (GRs), which are not substantially occupied until there is major stress-induced glucocorticoid secretion. Critically, it is increased MR occupancy that enhances synaptic plasticity, whereas increased occupancy of GRs impairs it; the inverted-U pattern emerges from these opposing effects. general, the effects of mild-to-moderate stress (that is, the left side of the U) are salutary, whereas those of severe stress are the opposite. In other words, it is not the case that stress is bad for you. It is major stress that is bad for you, whereas mild stress is anything but; when it is the optimal amount of stress, we love it. What constitutes optimal good stress? It occurs in a setting that feels safe; we voluntarily ride a roller coaster knowing that we are risking feeling a bit queasy, but not risking being decapitated. Moreover, good stress is transient; it is not by chance that a roller coaster ride is not 3 days long. And what is mild, transient stress in a benevolent setting? For this we have a variety of terms: arousal, alertness, engagement, play and stimulation (Fig. 1). The upswing of the inverted-U is the domain of any good educator who intuits the ideal space between a student being bored and being overwhelmed, where challenge is energized by a well-calibrated motivating sense of 'maybe'; after all, it is in the realm of plausible, but not guaranteed, reward that anticipatory bursts of mesolimbic dopamine release are the greatest19. And the downswing of the inverted-U is, of course, the universe of “stress is bad for you”. Thus, the ultimate goal of those studying stress is not to 'cure' us of it, but to optimize it.
Figure 1: Conceptualization of the inverted-U in the context of the benefits and costs of stress.

A broad array of neurobiological endpoints show the same property, which is that stress in the mild-to-moderate range (roughly corresponding to 10–20 μg dl−1 of corticosterone, the species-specific glucocorticoid of rats and mice) has beneficial, salutary effects; subjectively, when exposure is transient, we typically experience this range as being stimulatory. In contrast, both the complete absence of stress, or stress that is more severe and/or prolonged than that in the stimulatory range, have deleterious effects on those same neurobiological endpoints. The absence of stress is subjectively experienced as understimulatory by most, whereas the excess is typically experienced as overstimulatory, which segues into 'stressful'. Many of the inverted-U effects of stress in the brain are explained by the dual receptor system for glucocorticoids, where salutary effects are heavily mediated by increasing occupancy of the high-affinity, low-capacity MRs and deleterious effects are mediated by the low-affinity, high-capacity GRs.

Saturday, November 14, 2015

Shift happens

I'm passing on this interesting and scary 2014 video about our future, sent to me by a friend.

Friday, November 13, 2015

How to live what we don't believe.

Veteran readers of MindBlog will be aware that a continuing issue has been the problem of what to do with our understanding of how our brains really work - the fact that there is no free will, morality, or "I" of the sort we commonly suppose. (See for example "The I-Illusion," "Having no self..," "Are we really conscious.")

Two recent Op-Ed pieces in the NYTimes continue this thread: Risen and Nussbaum on "Believing What You Don't Believe" and William Irwin on "How to Live a Lie." Irwin considers morality, religion, and finally, free will:
When a novel or movie is particularly engrossing, our reactions to it may be involuntary and resistant to our attempts to counter them. We form what the philosopher Tamar Szabo Gendler calls aliefs — automatic belief-like attitudes that contrast with our well considered beliefs.
Like our involuntary screams in the theater, there may be cases of involuntary moral fictionalism or religious fictionalism as well. Among philosophical issues, though, free will seems to be the clearest case of involuntary fictionalism. It seems clear that I have free will when, for example, I choose from many options to order pasta at a restaurant. Yet few, if any, philosophical notions are harder to defend than free will. Even dualists, who believe in a nonmaterial soul, run into problems with divine foreknowledge. If God foresaw that I would order pasta, then was I really free to do otherwise, to order steak?
In the traditional sense, having free will means that multiple options are truly available to me. I am not a computer, running a decision-making program. No matter what I choose, I could have chosen otherwise. However, in a materialist, as opposed to dualist, worldview, there is no place in the causal chain of material things for the will to act in an uncaused way. Thus only one outcome of my decision-making process is possible. Not even quantum indeterminacy could give me the freedom to order steak. The moment after I recognize this, however, I go back to feeling as if my decision to order pasta was free and that my future decision of what to have for dessert will also be free. I am a free will fictionalist. I accept that I have free will even though I do not believe it.
Giving up on the possibility of free will in the traditional sense of the term, I could adopt compatibilism, the view that actions can be both determined and free. As long as my decision to order pasta is caused by some part of me — say my higher order desires or a deliberative reasoning process — then my action is free even if that aspect of myself was itself caused and determined by a chain of cause and effect. And my action is free even if I really could not have acted otherwise by ordering the steak.
Unfortunately, not even this will rescue me from involuntary free will fictionalism. Adopting compatibilism, I would still feel as if I have free will in the traditional sense and that I could have chosen steak and that the future is wide open concerning what I will have for dessert. There seems to be a “user illusion” that produces the feeling of free will.
William James famously remarked that his first act of free will would be to believe in free will. Well, I cannot believe in free will, but I can accept it. In fact, if free will fictionalism is involuntary, I have no choice but to accept free will. That makes accepting free will easy and undeniably sincere. Accepting the reality of God or morality, on the other hand, are tougher tasks, and potentially disingenuous.

Thursday, November 12, 2015

Amazing…. Robots learn coordinated behavior from scratch.

Der and Martius suggest that a novel plasticity rule can explain the development of sensorimotor intelligence, without having to postulate higher-level constructs such as intrinsic motivation, curiosity, or a specific reward system.  This seems to me to be groundbreaking and fascinating work. I pass on their overview video, and then some context from their introduction, which I recommend that you read.  Here is their abstract. (I don't even begin to understand the description of their feed-forward controller network and humanoid robot, which follows a “chaining together what changes together” rule. I can send motivated readers a PDF of the whole article with technical details and equations.)

Research in neuroscience produces an understanding of the brain on many different levels. At the smallest scale, there is enormous progress in understanding mechanisms of neural signal transmission and processing. At the other end, neuroimaging and related techniques enable the creation of a global understanding of the brain’s functional organization. However, a gap remains in binding these results together, which leaves open the question of how all these complex mechanisms interact. This paper advocates for the role of self-organization in bridging this gap. We focus on the functionality of neural circuits acquired during individual development by processes of self-organization—making complex global behavior emerge from simple local rules.
Donald Hebb’s formula “cells that fire together wire together” may be seen as an early example of such a simple local rule which has proven successful in building associative memories and perceptual functions. However, Hebb’s law and its successors...are restricted to scenarios where the learning is driven passively by an externally generated data stream. However, from the perspective of an autonomous agent, sensory input is mainly determined by its own actions. The challenge of behavioral self-organization requires a new kind of learning that bootstraps novel behavior out of the self-generated past experiences.
This paper introduces a rule which may be expressed as “chaining together what changes together.” This rule takes into account temporal structure and establishes contact to the external world by directly relating the behavioral level to the synaptic dynamics. These features together provide a mechanism for bootstrapping behavioral patterns from scratch.
This synaptic mechanism is neurobiologically plausible and raises the question of whether it is present in living beings. This paper aims to encourage such initiatives by using bioinspired robots as a methodological tool. Admittedly, there is a large gap between biological beings and such robots. However, in the last decade, robotics has seen a change of paradigm from classical AI thinking to embodied AI which recognizes the role of embedding the specific body in its environment. This has moved robotics closer to biological systems and supports their use as a testbed for neuroscientific hypotheses.
We deepen this argument by presenting concrete results showing that the proposed synaptic plasticity rule generates a large number of phenomena which are important for neuroscience. We show that up to the level of sensorimotor contingencies, self-determined behavioral development can be grounded in synaptic dynamics, without having to postulate higher-level constructs such as intrinsic motivation, curiosity, or a specific reward system. This is achieved with a very simple neuronal control structure by outsourcing much of the complexity to the embodiment [the idea of morphological computation].

Wednesday, November 11, 2015

Trusting robots, but not androids

Gilbert Chin points to work by Mathur and Reichling in the Journal Cognition.
Robots collect warehoused books, weld car parts together, and vacuum floors. As the number of android robots increases, however, concerns about the “uncanny valley” phenomenon—that people dislike a vaguely human-like robot more than either a machine-like robot or a real human—remain. Mathur and Reichling revisited whether human reactions to android robots exhibit an uncanny valley effect, using a set of 80 robot head shots gathered from the Internet and a systematically morphed set of six images extending from entirely robot to entirely human. Humans did adhere to the uncanny valley curve when rating the likeability of both sets of faces; what's more, this curve also described the extent to which those faces were trusted.
Here's the summary from the paper:

• Likability ratings of a large sample of real robot faces had a robust Uncanny Valley.
• Digitally composed robot face series demonstrated a similar Uncanny Valley.
• The Uncanny Valley may subtly alter humans’ trusting behavior toward robot partners.
• Category confusion may occur in the Uncanny Valley but did not mediate the effect. 

Android robots are entering human social life. However, human–robot interactions may be complicated by a hypothetical Uncanny Valley (UV) in which imperfect human-likeness provokes dislike. Previous investigations using unnaturally blended images reported inconsistent UV effects. We demonstrate an UV in subjects’ explicit ratings of likability for a large, objectively chosen sample of 80 real-world robot faces and a complementary controlled set of edited faces. An “investment game” showed that the UV penetrated even more deeply to influence subjects’ implicit decisions concerning robots’ social trustworthiness, and that these fundamental social decisions depend on subtle cues of facial expression that are also used to judge humans. Preliminary evidence suggests category confusion may occur in the UV but does not mediate the likability effect. These findings suggest that while classic elements of human social psychology govern human–robot social interaction, robust UV effects pose a formidable android-specific problem.

Tuesday, November 10, 2015

The unknowns of cognitive enhancement

Martha Farah points out how little is known about current methods of cognitive enhancement, and suggests several reasons why we are so ignorant. A few clips from her article:
...stimulants such as amphetamine and methylphenidate (sold under trade names such as Adderall and Ritalin, respectively) are widely used for nonmedical reasons …cognitive enhancement with stimulants is commonplace on college campuses…use by college faculty and other professionals to enhance workplace productivity has been documented…The published literature includes substantially different estimates of the effectiveness of prescription stimulants as cognitive enhancers. A recent meta-analysis suggests that the effect is most likely real but small for executive function tests stressing inhibitory control, and probably nonexistent for executive function tests stressing working memory.
Farah notes several studies suggesting that the effects of Adderall and another drug, modafinil (trade name Provigil) on ‘cognitive enhancement’ are actually effects on task motivation and mood.
The newest trend in cognitive enhancement is the use of transcranial electric stimulation. In the most widely used form, called transcranial direct current stimulation (tDCS), a weak current flows between an anode and a cathode placed on the head, altering the resting potential of neurons in the current's path….Transcranial electric stimulation is expanding …with new companies selling compact, visually appealing, user-friendly devices…published literature includes a mix of findings. One recent attempt to synthesize the literature with meta-analysis concluded that tDCS has no effect whatsoever on a wide range of cognitive abilities.
Why are we so ignorant about cognitive enhancement? Several factors seem to be at play. The majority of studies on enhancement effectiveness have been carried out on small samples, rarely more than 50 subjects, which limits their power. Furthermore, cognitive tasks typically lend themselves to a variety of different but reasonable outcome measures, such as overall errors, specific types of errors (for example, false alarms), and response times. In addition, there is usually more than one possible statistical approach to analyze the enhancement effect. Small samples and flexibility in design and analysis raise the likelihood of published false positives. In addition, pharmacologic and electric enhancements may differ in effectiveness depending on the biological and psychological traits of the user, which complicates the effort to understand the true enhancement potential of these technologies. Industry is understandably unmotivated to take on the expense of appropriate large-scale trials of enhancement, given that the stimulants used are illegally diverted and transcranial electric stimulation devices can be sold without such evidence. The inferential step from laboratory effect to real-world benefit adds another layer of challenge. Given that enhancements would likely be used for years, long-term effectiveness and safety are essential concerns but are particularly difficult and costly to determine. As a result, the only large-scale trial we may see is the enormous but uncontrolled and poorly monitored trial of people using these drugs and devices on their own.

Monday, November 09, 2015

Can we really change our aging?

I thought I would point MindBlog readers to a brief talk I gave, "Can we really change our aging?," at the Nov. 1, 2015 meeting of the Fort Lauderdale Prime Timers, and a Nov. 7 Lunch and Learn session of SAGE South Florida. It distills the contents of about 250 MindBlog posts I’ve written describing research on aging, and passes on some of the facts I think are most striking.

Friday, November 06, 2015

Critical period for visual pathway formation? - another dogma bites the dust.

India, which may have the largest number of blind children in the world, with estimates ranging from 360,000 to nearly 1.2 million, is providing a vast laboratory that has overturned one of the central dogmas of brain development - that development of visual (and other) pathways must take place within a critical time window, after which formation of proper connections becomes much more difficult or impossible. Until recently, children over 8 years old with congenital cataracts were not considered appropriate subjects for lens replacement surgery. In Science Magazine Rhitu Chatterjee describes a project begun in 2004, Led by neuroscientist Pawan Sinha, that has restored sight to much older children. The story of one 18-year old is followed, who over the 18 months following lens replacement begin to see with clarity that permitted him to bike through a crowded marketplace.

Of the nearly 500 children and young adults that have undergone cataract operation, about half became research subjects. One fascinating result that emerged is that visual experience isn't critical for certain visual function, the brain seems to be prewired, for example, to be fooled by some visual illusions that were thought to be a product of learning. One is the Ponzo illusion, which typically involves lines converging on the horizon (like train tracks) and two short parallel lines cutting across them. Although the horizontal lines are identical, the one nearer the horizon looks longer. If the Ponzo illusion were the result of visual learning, newly sighted kids wouldn't fall for it. But in fact, children who had just had their vision restored were just as susceptible to the Ponzo illusion as were control subjects with normal vision. The kids also fell for the Müller-Lyer illusion, a pair of lines with arrowheads on both ends; one set of arrowheads points outward, the other inward toward the line. The line with the inward arrowheads seems longer. These results lead Sinha to suggest that the illusion is being driven by very simple factors in the image that the brain is probably innately programmed to respond to.

Thursday, November 05, 2015

A biomarker for early detection of dementia

Kunz et al. show that in an at-risk group for developing Alzheimer's different brain signals are detected many decades before onset of the disease. Individuals showing this change would be candidates for starting therapy at early stages of the disease.
Alzheimer’s disease (AD) manifests with memory loss and spatial disorientation. AD pathology starts in the entorhinal cortex, making it likely that local neural correlates of spatial navigation, particularly grid cells, are impaired. Grid-cell–like representations in humans can be measured using functional magnetic resonance imaging. We found that young adults at genetic risk for AD (APOE-ε4 carriers) exhibit reduced grid-cell–like representations and altered navigational behavior in a virtual arena. Both changes were associated with impaired spatial memory performance. Reduced grid-cell–like representations were also related to increased hippocampal activity, potentially reflecting compensatory mechanisms that prevent overt spatial memory impairment in APOE-ε4 carriers. Our results provide evidence of behaviorally relevant entorhinal dysfunction in humans at genetic risk for AD, decades before potential disease onset.

Wednesday, November 04, 2015

Lifting weights and the brain.

Reynolds points to a study suggesting that light weight training slows down the shrinkage and tattering of our brain's white matter (nerve tracts) that normally occurs with aging. And, from the New Yorker:

Tuesday, November 03, 2015

Brain Pickings on 'the most important things'

I enjoy the weekly email sent out by Maria Popova's Brain Pickings website. I find it a bit overwhelming (and high on the estrogens), and so sample only a few of the idea chunks it presents. I suggest you have a look. On its 9th birthday, Brain Pickings noted the "9 most important things I have learned":
1.  Allow yourself the uncomfortable luxury of changing your mind.
2.  Do nothing for prestige or status or money or approval alone.
3. Be generous.
4. Build pockets of stillness into your life.
5. When people try to tell you who you are, don’t believe them.
6. Presence is far more intricate and rewarding an art than productivity.
7. Expect anything worthwhile to take a long time.
8. Seek out what magnifies your spirit.
9. Don’t be afraid to be an idealist.

Monday, November 02, 2015

A lab experiment: visibility of wealth increases wealth inequality

Nishi et al. do a fascinating laboratory experiment conducted online showing that when people can see wealth inequality in their social network, this propels further inequality through reduced cooperation and reduced social connectivity. From a summary by Gächter
Nishi and colleagues' experimental model used an assessment of people's willingness to contribute to public goods to test how initial wealth inequality and the structure of the social network influence the evolution of inequality...can mere observation of your neighbour's wealth lead to more inequality over time, even if such information does not change economic incentives? Visible wealth might have a psychological effect by triggering social comparisons and thereby influencing economic choices that have repercussions for inequality.
...the researchers endowed all participants with tokens, worth real a treatment without inequality, all participants initially received the same number of tokens; in a low-inequality treatment, participants had similar but different initial endowments; and in the high-inequality treatment there was a substantial starting difference between participants...A crucial manipulation in this experiment was wealth visibility. Under invisible conditions, the participants could observe only their own accumulated wealth. Under visibility, they could see the accumulated wealth of their connected neighbours but not the whole network....
The groups typically comprised 17 people arranged at random in a social network in which, on average, about 5 people were linked ('neighbours'). In each of the 10 rounds of the following game, participants had to decide whether to behave pro-socially ('cooperate') by reducing their own wealth by 50 tokens per connected neighbour to benefit each of them by 100 tokens, or to behave pro-selfishly ('defect') by keeping their tokens for themselves. These decisions had consequences for accumulated wealth levels and inequality. At the end of each round, the subjects learnt whether their neighbours had cooperated or defected and 30% of participants were given the opportunity to change their neighbour, that is, to either sever an existing link or to create a new one.
The authors find that, under high initial wealth inequality, visibility of neighbours' accumulated wealth increases inequality over time relative to the invisibility condition.
Here is the abstract from Nishi et al.:
Humans prefer relatively equal distributions of resources, yet societies have varying degrees of economic inequality. To investigate some of the possible determinants and consequences of inequality, here we perform experiments involving a networked public goods game in which subjects interact and gain or lose wealth. Subjects (n = 1,462) were randomly assigned to have higher or lower initial endowments, and were embedded within social networks with three levels of economic inequality (Gini coefficient = 0.0, 0.2, and 0.4). In addition, we manipulated the visibility of the wealth of network neighbours. We show that wealth visibility facilitates the downstream consequences of initial inequality—in initially more unequal situations, wealth visibility leads to greater inequality than when wealth is invisible. This result reflects a heterogeneous response to visibility in richer versus poorer subjects. We also find that making wealth visible has adverse welfare consequences, yielding lower levels of overall cooperation, inter-connectedness, and wealth. High initial levels of economic inequality alone, however, have relatively few deleterious welfare effects.

Friday, October 30, 2015

More exercise correlates with younger body cells.

Reynolds points to work by Loprinzi et al. showing physicaly active people have longer telomeres at the end of their chromosomes' DNA strands than sedentary people. (A telomere is a region of repetitive nucleotide sequences at each end of a chromatid, which protects the end of the chromosome from deterioration from from fusion with neighboring chromosomes. It's length is a measure of a cell's biological age because it naturally shortens and frays with age.) Here is their abstract, complete with three (unnecessary) abbreviations, LTL (leukocyte telomere length), PA (physical activity) and MBB (movement based behaviors), that you will have to keep in your short term memory for a few seconds: 

INTRODUCTION: Short leukocyte telomere length (LTL) has become a hallmark characteristic of aging. Some, but not all, evidence suggests that physical activity (PA) may play an important role in attenuating age-related diseases and may provide a protective effect for telomeres. The purpose of this study was to examine the association between PA and LTL in a national sample of US adults from the National Health and Nutrition Examination Survey.  
METHODS: National Health and Nutrition Examination Survey data from 1999 to 2002 (n = 6503; 20-84 yr) were used. Four self-report questions related to movement-based behaviors (MBB) were assessed. The four MBB included whether individuals participated in moderate-intensity PA, vigorous-intensity PA, walking/cycling for transportation, and muscle-strengthening activities. An MBB index variable was created by summing the number of MBB an individual engaged in (range, 0-4).  
RESULTS: A clear dose-response relation was observed between MBB and LTL; across the LTL tertiles, respectively, the mean numbers of MBB were 1.18, 1.44, and 1.54 (Ptrend less than 0.001). After adjustments (including age) and compared with those engaging in 0 MBB, those engaging in 1, 2, 3, and 4 MBB, respectively, had a 3% (P = 0.84), 24% (P = 0.02), 29% (P = 0.04), and 52% (P = 0.004) reduced odds of being in the lowest (vs highest) tertile of LTL; MBB was not associated with being in the middle (vs highest) tertile of LTL.  
CONCLUSIONS: Greater engagement in MBB was associated with reduced odds of being in the lowest LTL tertile.