Wednesday, September 23, 2015

More bad things about sleep debt.

This post is to point to two recent articles on pathologies induced by sleep debt. He et al. show that sleep restriction impairs blood-brain barrier function:
The blood–brain barrier (BBB) is a large regulatory and exchange interface between the brain and peripheral circulation. We propose that changes of the BBB contribute to many pathophysiological processes in the brain of subjects with chronic sleep restriction (CSR). To achieve CSR that mimics a common pattern of human sleep loss, we quantified a new procedure of sleep disruption in mice by a week of consecutive sleep recording. We then tested the hypothesis that CSR compromises microvascular function. CSR not only diminished endothelial and inducible nitric oxide synthase, endothelin1, and glucose transporter expression in cerebral microvessels of the BBB, but it also decreased 2-deoxy-glucose uptake by the brain. The expression of several tight junction proteins also was decreased, whereas the level of cyclooxygenase-2 increased. This coincided with an increase of paracellular permeability of the BBB to the small tracers sodium fluorescein and biotin. CSR for 6 d was sufficient to impair BBB structure and function, although the increase of paracellular permeability returned to baseline after 24 h of recovery sleep. This merits attention not only in neuroscience research but also in public health policy and clinical practice.
And, Weljie et al. find cross-species molecular markers of sleep debt:
Reduced sleep duration is a hallmark of modern-day society and is increasingly associated with medical conditions, such as diabetes, obesity, metabolic syndrome, and cardiovascular disease. Here we present data from a rat model and human clinical study of chronic sleep restriction, both revealing that two metabolites in blood, oxalic acid and diacylglycerol 36:3, are quantitatively depleted under sleep-restricted conditions and restored after recovery sleep. Our findings also reveal a significant overall shift in lipid metabolism, with higher levels of phospholipids in both species and evidence of a systemic oxidative environment. This work provides a potential link between the known pathologies of reduced sleep duration and metabolic dysfunction.

Tuesday, September 22, 2015

Our nervous systems are lazy.

Selinger et al. show that the subconscious nervous processes that regulate our movement are constantly adapting to minimize the energy required for movement in a given situation. To show this, they had subjects wear robotic exoskeletons that could increase or decrease resistance to the knees, to change the difficulty of swinging the legs during walking. Within minutes, gate was adjusted to be energetically more optimal.

Highlights
•People readily adapt established gait patterns to minimize energy use 
•People converge on new energetic optima within minutes, even for small cost savings 
•Updated predictions about energetically optimal gaits allow re-convergence within seconds 
•Energetic cost is not just an outcome of movement, but also continuously shapes it
Summary
People prefer to move in ways that minimize their energetic cost. For example, people tend to walk at a speed that minimizes energy use per unit distance and, for that speed, they select a step frequency that makes walking less costly. Although aspects of this preference appear to be established over both evolutionary and developmental timescales, it remains unclear whether people can also optimize energetic cost in real time. Here we show that during walking, people readily adapt established motor programs to minimize energy use. To accomplish this, we used robotic exoskeletons to shift people’s energetically optimal step frequency to frequencies higher and lower than normally preferred. In response, we found that subjects adapted their step frequency to converge on the new energetic optima within minutes and in response to relatively small savings in cost (less than 5%). When transiently perturbed from their new optimal gait, subjects relied on an updated prediction to rapidly re-converge within seconds. Our collective findings indicate that energetic cost is not just an outcome of movement, but also plays a central role in continuously shaping it.

Monday, September 21, 2015

The social mysteries of the superior temporal sulcus

Michael Beauchamp does a summary of work by Deen et al. (open access), who use functional magnetic resonance imaging (fMRI) to show a regular anterior–posterior organization in the STS for different social tasks such as theory of mind, biological motion, faces, voices and language. Here is the summary graphic:

Organization of social perception and cognition within the superior temporal sulcus (STS). Results of Deen et al. are shown on an inflated cortical surface model of the left and right hemisphere. Filled circles show the location of the peak activation, averaged across subjects, for each contrast. Colored regions show the extent of the activation for each contrast (multiple colored regions for some contrasts). 

Friday, September 18, 2015

A final musical/social at Twin Valley - some Rachmaninoff

A personal posting: On Sunday Sept. 13, Len and I hosted our last musical/social at the 1860 stone school house we have lived in for 25 years (I have been doing affairs like these since 1971-72). The following Wednesday, the Steinway B left for our Fort Lauderdale condo. The school house will be offered for sale in the spring of 2016, as we contract our Madison WI footprint to a condo near the university campus. Good friend Roy Wesley did video recordings of the concert, using a simple camera whose automatic volume control for audio damped out dynamic volume changes. I've posted these on YouTube, commentary and glitches included, just to have a record for myself and a few friends. I thought I would pass on the concert program, some pictures, an embedded video of the final Rachmaninoff  pieces, and URLS of the others, to MindBlog readers.

Program 
Chopin Nocturne in C# minor No. 18 (post.), Trois Ecossaises Op. 72 (post.) No. 3 
J. Brahms Capriccio Op 76. No 2; Waltzes, Op. 39 Nos.1, 12, 13, 14, 15. 
C. Debussy - Preludes Livre I - Danseuse de Delphes, Minstrels , Les Collines d’Anacapri 
F. Poulenc - Valse, Improvisation No. 14, Nocturne No. 2 
S.  Rachmaninoff Morceaux de fantasie (Fantasy pieces) Op. 3, No. 1, Elegie; No. 4, Polichinelle



Here is a video of the Rachmaninoff:





And URLs:
J. Brahms Capriccio Op 76. No 2; Waltzes, Op. 39 Nos.1, 12, 13, 14, 15
C. Debussy - Preludes Livre I - Danseuse de Delphes, Minstrels , Les Collines d’Anacapri 
F. Poulenc - Valse, Improvisation No. 14, Nocturne No. 2 

Thursday, September 17, 2015

Hormones and clothing choices.

Here is an interesting and curious bit from Eisenbruch et al.:
Recent evidence supports the idea that women use red clothing as a courtship tactic, and results from one study further suggested that women were more likely to wear red on days of high fertility in their menstrual cycles. Subsequent studies provided mixed support for the cycle-phase effect, although all such studies relied on counting methods of cycle-phase estimation and used between-subjects designs. By comparison, in the study reported here, we employed frequent hormone sampling to more accurately assess ovulatory timing and used a within-subjects design. We found that women were more likely to wear red during the fertile window than on other cycle days. Furthermore, within-subjects fluctuations in the ratio of estradiol to progesterone statistically mediated the within-subjects shifts in red-clothing choices. Our results appear to represent the first direct demonstration of specific hormone measurements predicting observable changes in women’s courtship-related behaviors. We also demonstrate the advantages of hormonal determination of ovulatory timing for tests of cycle-phase shifts in psychology or behavior.

Wednesday, September 16, 2015

Heritable risk of developing anxiety correlates with brain metabolism, not structure.

A group of Univ. of Wisconsin collaborators adds another installment to their series of articles on anxiety in a primate model for humans.

Significance
According to the World Health Organization, anxiety and depressive disorders are a leading source of disability, affecting hundreds of millions of people. Children can inherit an extremely anxious temperament, which is a prominent risk factor for the later development of anxiety, depression, and comorbid substance abuse. This study uses high-resolution functional and structural imaging in our well-established developmental nonhuman primate model to identify the heritable neural substrate that underlies extreme childhood anxious temperament. Using a large multigenerational family pedigree, genetic correlation analyses revealed a tripartite neural circuit where metabolism likely shares a genetic substrate with early-life dispositional anxiety. Interestingly, we found that brain function—not structure—is the critical intermediary between genetics and the childhood risk to develop stress-related psychopathology.
Abstract
Understanding the heritability of neural systems linked to psychopathology is not sufficient to implicate them as intergenerational neural mediators. By closely examining how individual differences in neural phenotypes and psychopathology cosegregate as they fall through the family tree, we can identify the brain systems that underlie the parent-to-child transmission of psychopathology. Although research has identified genes and neural circuits that contribute to the risk of developing anxiety and depression, the specific neural systems that mediate the inborn risk for these debilitating disorders remain unknown. In a sample of 592 young rhesus monkeys that are part of an extended multigenerational pedigree, we demonstrate that metabolism within a tripartite prefrontal-limbic-midbrain circuit mediates some of the inborn risk for developing anxiety and depression. Importantly, although brain volume is highly heritable early in life, it is brain metabolism—not brain structure—that is the critical intermediary between genetics and the childhood risk to develop stress-related psychopathology.

Tuesday, September 15, 2015

Inventing new words - iconic sounds are used.

Perlman and collaborators find that students inventing new words use certain types of vocalizations with certain words. For example, made-up words for “up” have a rising pitch, words for “down” have a falling pitch. “Slow” has a long duration and a low pitch, whereas “fast” has a short duration and high pitch. And “smooth” has a high degree of harmonicity, whereas “rough” has a high degree of the opposite quality—noise. This suggests that vocal communication systems can originate from spontaneously created iconic characteristics of sound, just as gestural communication systems can originate from spontaneously created iconic gestures. The chart shows the data describing characteristics of words invented for 18 contrasting ideas: up, down, big, small, good, bad, fast, slow, far, near, few, many, long, short, rough, smooth, attractive, and ugly.

The plots show the acoustic characteristics of each of the 18 meanings. The five variables are represented on the x-axis: D, duration; H, harmonics to noise ratio; I, intensity; P, pitch; C, pitch change. All values are normalized (z-scored) for each of the five measures. The red line shows the median and the blue box spans the first and third quartiles. The up and down arrows indicate variables that differed reliably between antonymic meanings. For example, vocalizations for bad differed from those for good by having a lower harmonics to noise ratio and pitch. The variables marked with arrows were the basis for the iconic template of each meaning.

Monday, September 14, 2015

Brain correlates of learning character traits versus rewards.

Hsu and Jenkins summarize work of Hackel et al. showing where our brains learn about traits versus rewards.
In a functional magnetic resonance imaging (fMRI) study..., Hackel et al use an innovative combination of ideas and tools from social psychology, economics and cognitive neuroscience, they offer neural evidence that associative learning processes are involved in making inferences about traits. Specifically, the authors conducted a study in which participants interacted repeatedly with eight different partners: four purported human participants and four slot machines. On each trial, participants chose to interact with one of two human (or slot machine) counterparts. The chosen counterpart, who had been endowed with a certain number of points on that trial, then shared some proportion of those points with the participant. Critically, targets varied orthogonally in terms of the average magnitude of their starting endowment (reward) and the average proportion of the endowment that was shared with the participant (generosity), enabling the authors to dissociate signals associated with trait learning from those associated with reward processing.
Consistent with the idea that trait learning engages associative learning processes, BOLD (blood oxygen level-dependent) responses of the ventral striatum during an initial training phase were predicted by an associative learning model that captures both reward and trait information. Moreover, two pieces of evidence support the idea that participants were able to make use of this trait information in a manner described by psychological theories of trait attribution. First, in a test phase in which participants knew each potential partner's starting endowment, participants chose interaction partners on the basis of those partners' past levels of generosity, and the extent to which they did so was associated with activity in the ventromedial prefrontal cortex (see figure). In addition, participants exhibited a tendency to generalize these generosity attributions, preferring the more generous targets when asked to pick a collaborator for a new, cooperative task-a hallmark of trait attribution.

Figure: Learning about traits versus rewards.  In an fMRI study, participants interacted with partners who varied in reward (the absolute amount of money shared with the participant) and generosity (the proportion shared). Activity in the ventromedial prefrontal cortex (vmPFC) was associated with preferring more generous targets, even when those targets shared less money in absolute terms.

Friday, September 11, 2015

Thinking too much - Self generated thought as the engine of neuroticism.

Perkins et al. offer an opinion piece in which they propose that the cost and benefits of neuroticism are surface manifestations of a tendency to engage in negatively hued self generated thought. I pass on their abstract and text from one of their figures:
•Existing neuroticism models cannot explain its link to both unhappiness and creativity. 
•Self-generated thought (SGT) facilitates creativity but can cause unhappiness. 
•Threat-related regions of medial prefrontal cortex (mPFC) generate blue-tinted SGT. 
•High neuroticism may reflect proneness to SGT arising from mPFC hyperactivity. 
Neuroticism is a dimension of personality that captures trait individual differences in the tendency to experience negative thoughts and feelings. Established theories explain neuroticism in terms of threat sensitivity, but have limited heuristic value since they cannot account for features of neuroticism that are unrelated to threat, such as creativity and negative psychological states experienced in benign, threat-free environments. We address this issue by proposing that neuroticism stems from trait individual differences in activity in brain circuits that govern the nature of self-generated thought (SGT). We argue our theory explains not only the association of neuroticism with threat sensitivity but also the prominence within the neurotic mind of representations of information that are unrelated to the way the world is right now, such as creativity and nonsituational ‘angst’.
A figure legend from the text (graphics did not have resolution adequate to display here):

Neuroticism, self-generated thought (SGT) and perceptions of threat intensity. (A) If an individual with ventromedial prefrontal cortex (vmPFC)/basolateral nuclei of the amygdala (BLA) that is twice as reactive as that of the average person switches from anxiety to panic when a spider encroaches within 4 m (an early switcher), then an average person will switch from anxiety to panic only when that same spider encroaches within 2 m (an ‘average switcher’). Conversely, a person with vmPFC/BLA that is half as reactive as that of the average person will switch from anxiety to panic only when that same spider encroaches within 1 m (a ‘late switcher’). The same psychological state (panic) is achieved in each individual, but the physical distance to threat that elicits it is different. (The graphic showed approaching spider.)(B) A model of how neuroticism is driven by individual differences in susceptibility to negatively hued SGT. Individuals who happen to have greater spontaneous activity in regions of mPFC associated with threat perception, experience frequent, spontaneous activation of threat-related amygdala circuits in situations that are wholly nonthreatening. (The graphic was picture of flowers.) In individuals who also happen to have a highly reactive vmPFC/BLA, these activations are likely to be sufficiently intense to be debilitating; therefore, such individuals present as being highly neurotic.

Thursday, September 10, 2015

Savoring happy memories - value representations in the striatum

Speer et al. observe responses in the corticostriatal circuits that respond to monetary reward when positive autobiographical memories are recalled. These response "may be adaptive for regulating positive emotion and promoting better well-being."

Highlights 
•The act of recalling positive life events enhances emotion and has tangible value
•Corticostriatal fMRI signals index emotion evoked by recalling positive life events
•Striatal activity relates to positive mood enhancing effects of reminiscing
•Striatal responses to positive memories may relate to individual resilience 
Summary 
Reminders of happy memories can bring back pleasant feelings tied to the original experience, suggesting an intrinsic value in reminiscing about the positive past. However, the neural circuitry underlying the rewarding aspects of autobiographical memory is poorly understood. Using fMRI, we observed enhanced activity during the recall of positive relative to neutral autobiographical memories in corticostriatal circuits that also responded to monetary reward. Enhanced activity in the striatum and medial prefrontal cortex was associated with increases in positive emotion during recall, and striatal engagement further correlated with individual measures of resiliency. Striatal response to the recall of positive memories was greater in individuals whose mood improved after the task. Notably, participants were willing to sacrifice a more tangible reward, money, in order to reminisce about positive past experiences. Our findings suggest that recalling positive autobiographical memories is intrinsically valuable, which may be adaptive for regulating positive emotion and promoting better well-being.

Wednesday, September 09, 2015

Convergent evolution of numerosity detection in bird and primate brains.

From Ditz and Nieder:
Birds are known for their advanced numerical competence, although a six-layered neocortex that is thought to enable primates with the highest levels of cognition is lacking in birds. We recorded neuronal activity from an endbrain association area termed nidopallium caudolaterale (NCL) in crows that discriminated the number of items in displays. NCL neurons were tuned to preferred numerosities. Neuronal discharges were relevant for the crows’ correct performance. Both the neuronal and the behavioral tuning functions were best described on a logarithmic number line, just as predicted by the psychophysical Weber–Fecher Law. The behavioral and neuronal numerosity representations in the crow reflect surprisingly well those found in the primate association cortex. This finding suggests that distantly related vertebrates with independently developed endbrains adopted similar neuronal solutions to process quantity - convergent evolution of a superior solution to a common computational problem.

Tuesday, September 08, 2015

A classification of cognitive mechanisms in meditation practice.

Dahl, Lutz, and Davidson offer an interesting classification system for different styles of meditation. Here is a paste up from their abstract and introduction:
Scientific research highlights the central role of specific psychological processes, in particular those related to the self, in various forms of human suffering and flourishing. This view is shared by Buddhism and other contemplative and humanistic traditions, which have developed meditation practices to regulate these processes. Building on a previous paper in this journal, we propose a novel classification system that categorizes specific styles of meditation into attentional, constructive, and deconstructive families based on their primary cognitive mechanisms. According to this model, the primary cognitive mechanisms in these three families are: (i) attention regulation and meta-awareness; (ii) perspective taking and reappraisal; and (iii) self-inquiry, respectively. To illustrate the role of these processes in different forms of meditation, we discuss how experiential fusion, maladaptive self-schema, and cognitive reification are differentially targeted by these processes in the context of Buddhist meditation, integrating the perspectives of other contemplative, philosophical, and clinical perspectives when relevant. The mechanisms and targets we propose are drawn from cognitive science and clinical psychology. Although these psychological processes are theoretically complex, as are the meditation practices that target them, we propose this novel framework as a first step in identifying specific cognitive mechanisms to aid in the scientific study of different families of meditation and the impact of these practices on well-being.
This article appears to be open source, and well worth reading for those interested in meditation. (I can send full text to motivated readers who have difficulty securing the full text.) I thought I would pass on just one edited clip from the section on the constructive family of meditation practices:
One of the most widely studied practices in the constructive family is the cultivation of compassion. Compassion training is held to alter core self-related processes, initiating a shift from self-oriented cognitive, affective, and behavioral patterns to patterns that are oriented toward the well-being of others...Research into the neural correlates of empathy has found that similar regions, including the insula, the anterior and mid-cingulate cortices, and the supplementary motor area, are activated across various forms of empathy...By way of contrast, compassion is linked to regions associated with reward, positive affect, and feelings of affection, such as the ventral striatum and medial orbitofrontal cortex...Studies of compassion training have also found increased activation in regions associated with executive function, including the dorsolateral prefrontal cortex and the anterior cingulate cortex...these preliminary findings suggest that cultivating compassion strengthens multiple networks, each of which may affect distinct psychological processes and thereby contribute to well-being in different ways.
Empathy and compassion also affect the peripheral biology of the human body. Perceiving stress in another individual has been linked to elevated cortisol levels, a relation that is more robust in those with high trait empathy, whereas compassion has been linked to lower levels of cortisol reactivity. Preliminary studies of compassion training have found associations between the amount of time spent engaging in compassion training and inflammatory biomarkers, with more compassion training leading to decreased levels of both C-reactive protein and interleukin 6. These findings suggest that the mind can be trained to orient itself toward the well-being of others and that this shift from self- to other-orientation impacts both the brain and the peripheral biology of the body and, in particular, the way the body responds to environmental stressors. Further research is required to elucidate the precise mechanisms through which these states affect the body, and also to investigate how changes in peripheral biology reciprocally impact psychological processes and the relationship between these processes and well-being.

Monday, September 07, 2015

Brain imaging can predict six-year outcomes in children’s numerical abilities.

Interesting work from Evans et al.:

Significance Statement
Children show substantial individual differences in math abilities and ease of math learning. Early numerical abilities provide the foundation for future academic and professional success in an increasingly technological society. Understanding the early identification of poor math skills has therefore taken on great significance. This work provides important new insights into brain structure and connectivity measures that can predict longitudinal growth of children's math skills over a 6 year period, and may eventually aid in the early identification of children who might benefit from targeted interventions.
Abstract
Early numerical proficiency lays the foundation for acquiring quantitative skills essential in today's technological society. Identification of cognitive and brain markers associated with long-term growth of children's basic numerical computation abilities is therefore of utmost importance. Previous attempts to relate brain structure and function to numerical competency have focused on behavioral measures from a single time point. Thus, little is known about the brain predictors of individual differences in growth trajectories of numerical abilities. Using a longitudinal design, with multimodal imaging and machine-learning algorithms, we investigated whether brain structure and intrinsic connectivity in early childhood are predictive of 6 year outcomes in numerical abilities spanning childhood and adolescence. Gray matter volume at age 8 in distributed brain regions, including the ventrotemporal occipital cortex (VTOC), the posterior parietal cortex, and the prefrontal cortex, predicted longitudinal gains in numerical, but not reading, abilities. Remarkably, intrinsic connectivity analysis revealed that the strength of functional coupling among these regions also predicted gains in numerical abilities, providing novel evidence for a network of brain regions that works in concert to promote numerical skill acquisition. VTOC connectivity with posterior parietal, anterior temporal, and dorsolateral prefrontal cortices emerged as the most extensive network predicting individual gains in numerical abilities. Crucially, behavioral measures of mathematics, IQ, working memory, and reading did not predict children's gains in numerical abilities. Our study identifies, for the first time, functional circuits in the human brain that scaffold the development of numerical skills, and highlights potential biomarkers for identifying children at risk for learning difficulties.

Friday, September 04, 2015

Bioethics - Doing more harm than good?

Steven Pinker recently ignited a small firestorm with his piece in the Boston Globe arguing that bioethical issues that slow down research have a massive human cost. "Even a one-year delay in implementing an effective treatment could spell death, suffering, or disability for millions of people." Below are some clips from his piece, and rebuttals to Pinker's points can be found in this Nature article:
Biomedical research, then, promises vast increases in life, health, and flourishing. Just imagine how much happier you would be if a prematurely deceased loved one were alive, or a debilitated one were vigorous — and multiply that good by several billion, in perpetuity. Given this potential bonanza, the primary moral goal for today’s bioethics can be summarized in a single sentence.
Get out of the way.
A truly ethical bioethics should not bog down research in red tape, moratoria, or threats of prosecution based on nebulous but sweeping principles such as “dignity,” “sacredness,” or “social justice.” Nor should it thwart research that has likely benefits now or in the near future by sowing panic about speculative harms in the distant future. These include perverse analogies with nuclear weapons and Nazi atrocities, science-fiction dystopias like “Brave New World’’ and “Gattaca,’’ and freak-show scenarios like armies of cloned Hitlers, people selling their eyeballs on eBay, or warehouses of zombies to supply people with spare organs. Of course, individuals must be protected from identifiable harm, but we already have ample safeguards for the safety and informed consent of patients and research subjects.
Biomedical research in particular is defiantly unpredictable. The silver-bullet cancer cures of yesterday’s newsmagazine covers, like interferon and angiogenesis inhibitors, disappointed the breathless expectations, as have elixirs such as antioxidants, Vioxx, and hormone replacement therapy. Nineteen years after Dolly the sheep was cloned, we are nowhere near seeing parents implanting genes for musical, athletic, or intellectual talent in their unborn children.
In the other direction, treatments that were decried in their time as paving the road to hell, including vaccination, transfusions, anesthesia, artificial insemination, organ transplants, and in-vitro fertilization, have become unexceptional boons to human well-being.
Biomedical advances will always be incremental and hard-won, and foreseeable harms can be dealt with as they arise. The human body is staggeringly complex, vulnerable to entropy, shaped by evolution for youthful vigor at the expense of longevity, and governed by intricate feedback loops which ensure that any intervention will be compensated for by other parts of the system. Biomedical research will always be closer to Sisyphus than a runaway train — and the last thing we need is a lobby of so-called ethicists helping to push the rock down the hill.

Thursday, September 03, 2015

Oxytocin - more sophisticated views of its functions

Helen Shen offers a review of studies on oxytocin, the “hug hormone,” which influences maternal behavior and social attachment in various species. She notes research showing that oxytocin acts on inhibitory interneurons in a way that quiets background chatter within neuronal circuits, and thus may help social interaction and recognition is by enhancing the brain's response to socially relevant sights, sounds or other stimuli. MindBlog has done posts on experiments showing that oxytocin, delivered through an intranasal spray, can promote various aspects of social behavior in healthy adults. People who inhale oxytocin before playing an investment game are more willing to entrust their money to a stranger than are placebo-treated players. A dose of the hormone increases the amount of time people spend gazing at the eye region of faces, and improves their ability to infer the emotional state of others from subtle expressions. Shen’s review also summarizes efforts to test oxytocin’s usefulness in treating psychiatric disorders such as autism.

Wednesday, September 02, 2015

Birth of the moralizing gods.

Lizzie Wade offers two interesting summaries of work on the evolution of religion that suggest that as societies grew bigger, so did their gods. She describes the efforts of Anders Petersen, who is asking religious studies scholars to contribute his "Database of Religious History" project by answering a series of questions about the ancient religions in which each of them specialize. This kind of survey can help in testing a “big gods” hypothesis: "Did moralizing gods, community-wide rituals, and supernatural punishment emerge before or after societies became politically complex? Has any large-scale society succeeded without prosocial religion? And what does “moralizing” really mean in different cultures and at different times?" Wade's second article describes work of Ara Norenzayan and others suggesting that judgemental deities were the key to obtaining the cooperation needed to build and sustain large and complex ancient societies..."once big gods and big societies existed, the moralizing gods helped religions as dissimilar as Islam and Mormonism spread by making groups of the faithful more cooperative, and therefore more successful."

Tuesday, September 01, 2015

The benefits of reading to children.

Two items...First, from Montag et al.:
Young children learn language from the speech they hear. Previous work suggests that greater statistical diversity of words and of linguistic contexts is associated with better language outcomes. One potential source of lexical diversity is the text of picture books that caregivers read aloud to children. Many parents begin reading to their children shortly after birth, so this is potentially an important source of linguistic input for many children. We constructed a corpus of 100 children’s picture books and compared word type and token counts in that sample and a matched sample of child-directed speech. Overall, the picture books contained more unique word types than the child-directed speech. Further, individual picture books generally contained more unique word types than length-matched, child-directed conversations. The text of picture books may be an important source of vocabulary for young children, and these findings suggest a mechanism that underlies the language benefits associated with reading to children.
And, Hutton et al. note that children with greater home reading exposure exhibit higher activation of left-sided brain regions involved with semantic processing (extraction of meaning).

Monday, August 31, 2015

Self-policing by psychologists - many prominent experiments fail replication tests

Benedict Carey offers context, summary, and reactions to the recent Science article reporting work of a consortium of 270 scientists on five continents led by psychologist Brian Nosek at the University of Virginia. (Other commentaries on this work are offered by Bohannon and by The Guardian.) The bottom line is that only 36 percent of the findings from almost 100 studies in the top three psychology journals held up when the original experiments were rigorously redone. This work was an 'inside job,' with psychologists doing the replication attempts communicating with cooperative original researchers. Carey describes a culture change that is taking hold in the psychological research community, towards greater transparency, data sharing, and preregistration of studies with journals that spells out hypotheses and how they are going to be tested. "Doing this upfront is a powerful check against moving the goal posts on a study — that is, analyzing the data and working backward, reverse-engineering the “hypothesis” to fit those findings."

(addendum 9/1/2015:  another useful commentary, "Psychology is Not in Crisis")

A beta-blocker facilitates fear extinction.

Fitzgerald et al. show, using a rat model, that propranolol, a Î²-noradrenergic receptor blocker, can facilitate extinction of posttraumatic stress. Significance
Posttraumatic stress disorder is characterized by a resistance to extinction learning and dysregulated signaling of the neurotransmitter norepinephrine. Previous research suggested the prelimbic and infralimbic subdivisions of the medial prefrontal cortex (mPFC) regulate fear expression and suppression, respectively. However, noradrenergic signaling in response to psychological stress may disrupt mPFC function, contributing to extinction deficits. Here we show, for the first time to our knowledge, that footshock stress dysregulates mPFC spike firing; this can be stabilized by propranolol, a β-noradrenergic receptor blocking drug, which in turn facilitates extinction when it normally fails. These findings suggest that propranolol may be a particularly effective adjunct to behavioral therapy soon after trauma, when stress is high, at least in part by normalizing prefrontal cortical function.
Abstract
Stress-induced impairments in extinction learning are believed to sustain posttraumatic stress disorder (PTSD). Noradrenergic signaling may contribute to extinction impairments by modulating medial prefrontal cortex (mPFC) circuits involved in fear regulation. Here we demonstrate that aversive fear conditioning rapidly and persistently alters spontaneous single-unit activity in the prelimbic and infralimbic subdivisions of the mPFC in behaving rats. These conditioning-induced changes in mPFC firing were mitigated by systemic administration of propranolol (10 mg/kg, i.p.), a β-noradrenergic receptor antagonist. Moreover, propranolol administration dampened the stress-induced impairment in extinction observed when extinction training is delivered shortly after fear conditioning. These findings suggest that β-adrenoceptors mediate stress-induced changes in mPFC spike firing that contribute to extinction impairments. Propranolol may be a helpful adjunct to behavioral therapy for PTSD, particularly in patients who have recently experienced trauma.

Friday, August 28, 2015

The collaborative roots of corruption.

Here is a neat piece of work, by Weisel and Shalvi:

Significance
Recent financial scandals highlight the devastating consequences of corruption. While much is known about individual immoral behavior, little is known about the collaborative roots of corruption. In a novel experimental paradigm, people could adhere to one of two competing moral norms: collaborate vs. be honest. Whereas collaborative settings may boost honesty due to increased observability, accountability, and reluctance to force others to become accomplices, we show that collaboration, particularly on equal terms, is inductive to the emergence of corruption. When partners' profits are not aligned, or when individuals complete a comparable task alone, corruption levels drop. These findings reveal a dark side of collaboration, suggesting that human cooperative tendencies, and not merely greed, take part in shaping corruption.
Abstract
Cooperation is essential for completing tasks that individuals cannot accomplish alone. Whereas the benefits of cooperation are clear, little is known about its possible negative aspects. Introducing a novel sequential dyadic die-rolling paradigm, we show that collaborative settings provide fertile ground for the emergence of corruption. In the main experimental treatment the outcomes of the two players are perfectly aligned. Player A privately rolls a die, reports the result to player B, who then privately rolls and reports the result as well. Both players are paid the value of the reports if, and only if, they are identical (e.g., if both report 6, each earns €6). Because rolls are truly private, players can inflate their profit by misreporting the actual outcomes. Indeed, the proportion of reported doubles was 489% higher than the expected proportion assuming honesty, 48% higher than when individuals rolled and reported alone, and 96% higher than when lies only benefited the other player. Breaking the alignment in payoffs between player A and player B reduced the extent of brazen lying. Despite player B's central role in determining whether a double was reported, modifying the incentive structure of either player A or player B had nearly identical effects on the frequency of reported doubles. Our results highlight the role of collaboration—particularly on equal terms—in shaping corruption. These findings fit a functional perspective on morality. When facing opposing moral sentiments—to be honest vs. to join forces in collaboration—people often opt for engaging in corrupt collaboration.

Thursday, August 27, 2015

What emotions are and aren’t.

Barrett uses a very useful analogy to describe the misguided search for "where in the brain" particular emotions occur:
...if you listen to a recorded symphony through stereo speakers that are placed exactly right, the orchestra will sound like it’s inside your head. Obviously that isn’t the case...You might find yourself asking well-meaning but preposterous scientific questions like “Where in the brain is the woodwinds section located?” ..A more reasonable approach is not to ask...How does the brain construct this experience of hearing the orchestra in your head?
Most people, including many scientists, believe that emotions are distinct, locatable entities inside us — but they’re not. Searching for emotions in this form is as misguided as looking for cerebral clarinets and oboes.
The Interdisciplinary Affective Science Laboratory (which I direct) collectively analyzed brain-imaging studies published from 1990 to 2011 that examined fear, sadness, anger, disgust and happiness. We divided the human brain virtually into tiny cubes, like 3-D pixels, and computed the probability that studies of each emotion found an increase in activation in each cube...Overall, we found that no brain region was dedicated to any single emotion. We also found that every alleged “emotion” region of the brain increased its activity during nonemotional thoughts and perceptions as well.
Brain regions like the amygdala are certainly important to emotion, but they are neither necessary nor sufficient for it. In general, the workings of the brain are not one-to-one, whereby a given region has a distinct psychological purpose. Instead, a single brain area like the amygdala participates in many different mental events, and many different brain areas are capable of producing the same outcome. Emotions like fear and anger, my lab has found, are constructed by multipurpose brain networks that work together.
If emotions are not distinct neural entities, perhaps they have a distinct bodily pattern — heart rate, respiration, perspiration, temperature and so on? Again, the answer is no. My lab analyzed over 200 published studies, covering nearly 22,000 test subjects, and found no consistent and specific fingerprints in the body for any emotion. Instead, the body acts in diverse ways that are tied to the situation.
...emotion words like “anger,” “happiness” and “fear” each name a population of diverse biological states that vary depending on the context...Instead of asking where emotions are or what bodily patterns define them, we would do better to abandon such essentialism and ask the more revealing question, “How does the brain construct these incredible experiences?”

Wednesday, August 26, 2015

Stress can cause bad food choices and compromise long term goals.

Maier et al. show that more immediate rewards are likely to be chosen following stress because stress increases immediate reward signaling in the amygdala and striatum during choice. Subjects were stressed by having to hold a hand in ice water as long as possible, and then asked to select between more and less healthy food choices while in an MRI scanner, knowing that they would be expected to eat of their picks at the end of the test.
Important decisions are often made under stressful circumstances that might compromise self-regulatory behavior. Yet the neural mechanisms by which stress influences self-control choices are unclear. We investigated these mechanisms in human participants who faced self-control dilemmas over food reward while undergoing fMRI following stress. We found that stress increased the influence of immediately rewarding taste attributes on choice and reduced self-control. This choice pattern was accompanied by increased functional connectivity between ventromedial prefrontal cortex (vmPFC) and amygdala and striatal regions encoding tastiness. Furthermore, stress was associated with reduced connectivity between the vmPFC and dorsolateral prefrontal cortex regions linked to self-control success. Notably, alterations in connectivity pathways could be dissociated by their differential relationships with cortisol and perceived stress. Our results indicate that stress may compromise self-control decisions by both enhancing the impact of immediately rewarding attributes and reducing the efficacy of regions promoting behaviors that are consistent with long-term goals.

Tuesday, August 25, 2015

Disadvantage, self control, and health

A very sobering study from Miller et al:
There are persistent socioeconomic disparities in many aspects of child development in America. Relative to their affluent peers, children of low socioeconomic status (SES) complete fewer years of education, have a higher prevalence of health problems, and are convicted of more criminal offenses. Based on research indicating that low self-control underlies some of these disparities, policymakers have begun incorporating character-skills training into school curricula and social services. However, emerging data suggest that for low-SES youth, self-control may act as a “double-edged sword,” facilitating academic success and psychosocial adjustment, while at the same time undermining physical health. Here, we examine this hypothesis in a five-wave study of 292 African American teenagers from rural Georgia. From ages 17 to 20 y, we assessed SES and self-control annually, along with depressive symptoms, substance use, aggressive behavior, and internalizing problems. At age 22 y, we obtained DNA methylation profiles of subjects’ peripheral blood mononuclear cells. These data were used to measure epigenetic aging, a methylation-derived biomarker reflecting the disparity between biological and chronological aging. Among high-SES youth, better mid-adolescent self-control presaged favorable psychological and methylation outcomes. However, among low-SES youth, self-control had divergent associations with these outcomes. Self-control forecasted lower rates of depressive symptoms, substance use, aggressive behavior, and internalizing problems but faster epigenetic aging. These patterns suggest that for low-SES youth, resilience is a “skin-deep” phenomenon, wherein outward indicators of success can mask emerging problems with health. These findings have conceptual implications for models of resilience, and practical implications for interventions aimed at ameliorating social and racial disparities.

Monday, August 24, 2015

Biased internet search engines might influence election outcomes

Just in case you are not pessimistic enough already about election manipulations that insure our continued governance by the 1% for the 1% , here is more disturbing information from Epstein and Robertson on the effect that biased internet search engines can have.  (And, see Epstein's article in Politico "How Google could influence the next election"):

Significance
We present evidence from five experiments in two countries suggesting the power and robustness of the search engine manipulation effect (SEME). Specifically, we show that (i) biased search rankings can shift the voting preferences of undecided voters by 20% or more, (ii) the shift can be much higher in some demographic groups, and (iii) such rankings can be masked so that people show no awareness of the manipulation. Knowing the proportion of undecided voters in a population who have Internet access, along with the proportion of those voters who can be influenced using SEME, allows one to calculate the win margin below which SEME might be able to determine an election outcome.
Abstract
Internet search rankings have a significant impact on consumer choices, mainly because users trust and choose higher-ranked results more than lower-ranked results. Given the apparent power of search rankings, we asked whether they could be manipulated to alter the preferences of undecided voters in democratic elections. Here we report the results of five relevant double-blind, randomized controlled experiments, using a total of 4,556 undecided voters representing diverse demographic characteristics of the voting populations of the United States and India. The fifth experiment is especially notable in that it was conducted with eligible voters throughout India in the midst of India’s 2014 Lok Sabha elections just before the final votes were cast. The results of these experiments demonstrate that (i) biased search rankings can shift the voting preferences of undecided voters by 20% or more, (ii) the shift can be much higher in some demographic groups, and (iii) search ranking bias can be masked so that people show no awareness of the manipulation. We call this type of influence, which might be applicable to a variety of attitudes and beliefs, the search engine manipulation effect. Given that many elections are won by small margins, our results suggest that a search engine company has the power to influence the results of a substantial number of elections with impunity. The impact of such manipulations would be especially large in countries dominated by a single search engine company.

Friday, August 21, 2015

Introverts prefer mountains.

From Oishi et al.:
In five studies, we tested the link between personality and geography. We found that mountain-lovers were more introverted than ocean-lovers (Study 1). People preferred the ocean over mountains when they wanted to socialize with others, but they preferred the mountains and the ocean equally when they wanted to decompress alone (Study 2). In Study 3, we replicated the introversion–extraversion differences using pictures of mountains and oceans. Furthermore, this difference was explained in part by extraverts’ perception that it would take more work to have fun in the mountains than in the ocean. Extending the first three studies to non-students, we found that residents of mountainous U.S. states were more introverted than residents of flat states (Study 4). In Study 5, we tested the link between introversion and the mountains experimentally by sending participants to a flat, open area or a secluded, wooded area. The terrain did not make people more introverted, but introverts were happier in the secluded area than in the flat/open area, which is consistent with the person–environment fit hypothesis.

Thursday, August 20, 2015

Unequal, but happy

I just came across an article in my queue of potential posts by Steven Quantz and Anette Asp that I had put aside, thinking to check whether this was the same Quantz who I vaguely remember reviewing my Biology of Mind book some time ago. I hunted down the review (in Trends in Neuroscience, May 2000) and sure enough, it is the same guy, then and now at Cal Tech, a professor of philosophy who atempts to relate advances in understanding the neuroscience of the brain to the humanities and social sciences, in fields such as neuroethics, neuroaesthetics, and neuroeconomics.

His piece with Asp in the NY Times Sunday Review deals with the same topic as my July 10 post, "Why don't the poor rise up?", and takes another perspective, described in their recent book "Cool"- How the Brain’s Hidden Quest for Cool Drives Our Economy and Shapes Our World.
...inequality is increasingly disorganized. Consumerism has expanded the lifestyles, niches and brands that supply the statuses we seek.

As a result, social status, which was once hierarchical and zero-sum, has become more fragmented, pluralistic and subjective. The relationship between relative income and relative status, which used to be straightforward, has gotten much more complex.

By the 1950s, rapidly rising standards of living across the West, combined with social pressures to conform, all conspired to intensify status competition. The architects of “rebel cool,” like Jack Kerouac and Norman Mailer, responded by rebelling against emulation consumption and the status hierarchy of postwar America. They inverted the dominant social hierarchy, rejecting the values of those at the top and appropriating the values of those who had been marginalized at the bottom.

The pursuit of “the cool,” in our view, fundamentally altered the psychological motivations underlying our consumer choices. In conspicuous consumption, our emulation of higher-ups means we compete directly for status because we want what they have. But rebellious consumption changed the game, by making a product’s worth depend on how it embodied values that rejected a dominant group’s status.

By comparing a PC user to an Orwellian drone while likening a Mac user to a sexy athlete in its iconic “1984” ad, Apple made a fundamental claim about the allure of its products. Today, Apple products are expensive because they’re seen as cool; they’re not cool because they’re expensive (which is still the case for many luxury goods).

Asking people merely to look at products and people they considered “cool” sparks a pattern of brain activation in the medial prefrontal cortex — a part of the brain that is involved in daydreaming, planning and ruminating — similar to what happens when people receive praise. Our brain’s medial prefrontal cortex, in short, tracks our social esteem.

A new generation of ethnographers has discovered an explosion of consumer lifestyles and product diversification in recent decades. From evangelical Christian Harley-Davidson owners...to lifestyles organized around musical tastes, from the solidarity of punk rockers to yoga gatherings, from meditation retreats to book clubs, we use products to create and experience community. These communities often represent a consumer micro-culture, a “brand community,” or tribe, with its own values and norms about status.

The proliferation of consumer choice helps explain why today’s Gilded Age hasn’t sparked as much outrage as the last one. Money may not buy happiness in the long run, but consumer choice has gone a long way in keeping most Americans reasonably content, even if they shouldn’t be.

Wednesday, August 19, 2015

People who eat spicy food live longer.

I pass on this interesting bit of information because I, like my father and grandfather, am addicted to hot sauce containing chili peppers (use it with every breakfast). Their main ingredient is capsaicin, which is known to have antioxidant and anti-inflammatory properties. A huge Chinese study of 485,000 people over an average of more than seven years found consuming spicy food once a day correlated with a 14% reduction in risk of death, and also reduced rates of ischemic heart disease, respiratory diseases and cancers.

Tuesday, August 18, 2015

Tracking ongoing cognition with fMRI of functional connectivity states.

This work by Gonzalez-Castillo at al. shows how close we are getting to real time monitoring of brain activity associated with different kinds of tasks (in this study, distinguishing functional connectivity distinctive to memory vs. rest, math vs. rest, and video vs. rest.)
Functional connectivity (FC) patterns in functional MRI exhibit dynamic behavior on the scale of seconds, with rich spatiotemporal structure and limited sets of whole-brain, quasi-stable FC configurations (FC states) recurring across time and subjects. Based on previous evidence linking various aspects of cognition to group-level, minute-to-minute FC changes in localized connections, we hypothesized that whole-brain FC states may reflect the global, orchestrated dynamics of cognitive processing on the scale of seconds. To test this hypothesis, subjects were continuously scanned as they engaged in and transitioned between mental states dictated by tasks. FC states computed within windows as short as 22.5 s permitted robust tracking of cognition in single subjects with near perfect accuracy. Accuracy dropped markedly for subjects with the lowest task performance. Spatially restricting FC information decreased accuracy at short time scales, emphasizing the distributed nature of whole-brain FC dynamics, beyond univariate magnitude changes, as valuable markers of cognition.

Monday, August 17, 2015

Anti-aging therapies? Start by quantifying aging in young adults for early intervention.

Belsky et al. show that aging processes can be quantified in people still young enough for prevention of age-related disease, opening a new door for antiaging therapies.
Antiaging therapies show promise in model organism research. Translation to humans is needed to address the challenges of an aging global population. Interventions to slow human aging will need to be applied to still-young individuals. However, most human aging research examines older adults, many with chronic disease. As a result, little is known about aging in young humans. We studied aging in 954 young humans, the Dunedin Study birth cohort, tracking multiple biomarkers across three time points spanning their third and fourth decades of life. We developed and validated two methods by which aging can be measured in young adults, one cross-sectional and one longitudinal. Our longitudinal measure allows quantification of the pace of coordinated physiological deterioration across multiple organ systems (e.g., pulmonary, periodontal, cardiovascular, renal, hepatic, and immune function). We applied these methods to assess biological aging in young humans who had not yet developed age-related diseases. Young individuals of the same chronological age varied in their “biological aging” (declining integrity of multiple organ systems). Already, before midlife, individuals who were aging more rapidly were less physically able, showed cognitive decline and brain aging, self-reported worse health, and looked older. Measured biological aging in young adults can be used to identify causes of aging and evaluate rejuvenation therapies.

Friday, August 14, 2015

Exercise for the aging brain - how much is necessary?

Gretchen Reynolds points to interesting work on exercise and the aging brain by Vidoni et. al. Increasing amounts of aerobic exercise (75, 150, 225 minutes per week of walking) correlated with correspondingly increased cardiorespiratory fitness, but the degree of improvement in thinking skills, compared with non-exercising controls, was the same regardless of the duration of exercise. This suggests that a small dose of exercise may be sufficient to improve many aspects of thinking.

Thursday, August 13, 2015

What is fair? It depends on your culture.

Tomasello and collaborators note interesting cultural differences in distributive justice:
Distributing the spoils of a joint enterprise on the basis of work contribution or relative productivity seems natural to the modern Western mind. But such notions of merit-based distributive justice may be culturally constructed norms that vary with the social and economic structure of a group. In the present research, we showed that children from three different cultures have very different ideas about distributive justice. Whereas children from a modern Western society distributed the spoils of a joint enterprise precisely in proportion to productivity, children from a gerontocratic pastoralist society in Africa did not take merit into account at all. Children from a partially hunter-gatherer, egalitarian African culture distributed the spoils more equally than did the other two cultures, with merit playing only a limited role. This pattern of results suggests that some basic notions of distributive justice are not universal intuitions of the human species but rather culturally constructed behavioral norms.

Wednesday, August 12, 2015

Knowing the internal states of ourselves and of others.

We frequently can infer the emotional state of someone from the style of their movement, distinguishing, for example, when they hand us something rudely versus gently. The time, space, force, trajectory, and direction of the handing movement differ, reflecting what Rizzolattia and colleagues call different 'vitality forms.' They find that vitality forms in the three different tasks of action observation, imagination, and self execution correlate with consistent activation of the dorsocentral sector of the insula:
Vitality form is a term that describes the style with which motor actions are performed (e.g., rude, gentle, etc.). They represent one characterizing element of conscious and unconscious bodily communication. Despite their importance in interpersonal behavior, vitality forms have been, until now, virtually neglected in neuroscience. Here, using the functional MRI (fMRI) technique, we investigated the neural correlates of vitality forms in three different tasks: action observation, imagination, and execution. Conjunction analysis showed that, in all three tasks, there is a common, consistent activation of the dorsocentral sector of the insula. In addition, a common activation of the parietofrontal network, typically active during arm movements production, planning, and observation, was also found. We conclude that the dorsocentral part of the insula is a key element of the system that modulates the cortical motor activity, allowing individuals to express their internal states through action vitality forms. Recent monkey anatomical data show that the dorsocentral sector of the insula is, indeed, connected with the cortical circuit involved in the control of arm movements.

Tuesday, August 11, 2015

Overclaiming - the illusion of knowledge

Atir et al. probe how our inflated perception of our expertise can lead us to make claims of impossible knowledge. Their edited abstract:
People overestimate their knowledge, at times claiming knowledge of concepts, events, and people that do not exist and cannot be known, a phenomenon called overclaiming. What underlies assertions of such impossible knowledge? We found that people overclaim to the extent that they perceive their personal expertise favorably. A first set of studies showed that self-perceived financial knowledge positively predicts claiming knowledge of nonexistent financial concepts (invented by the researchers: pre-rated stocks, fixed-rate deduction, annualized credit), independent of actual knowledge. A second study demonstrated that self-perceived knowledge within specific domains (e.g., biology) is associated specifically with overclaiming within those domains (taking the fictitious terms meta-toxins, bio-sexual, and retroplex to be real). In another study, warning participants that some of the concepts they saw were fictitious did not reduce the relationship between self-perceived knowledge and overclaiming, which suggests that this relationship is not driven by impression management. Finally, boosting self-perceived expertise in geography (by having participants take an easy versus difficult geography quiz) prompted assertions of familiarity with nonexistent places, which supports a causal role for self-perceived expertise in claiming impossible knowledge.
The authors note this line by American historial Daniel Boorstin (1914-2004): "The menace to understanding is not so much ignorance as the illusion of knowledge."

Monday, August 10, 2015

Habitual exercise correlates with lower distractibility.

Yet another demonstration of the salutary effects of long term exercise on mental function:
Aging is associated with compromised executive control functions. Several lines of evidence point to beneficial effects of physical activity on cognition which indicate that regular physical activity may counteract the age-related decline of some executive functions. Here, we investigate the effects of lifelong physical activity (about 50 years) on interference processing in two matched groups of 20 physically high active and 20 low active healthy older men using event-related potentials (ERPs). In a low interference block of the Stroop task, participants had to indicate the meaning of color-words, while color was either compatible or incompatible with the meaning. In the high interference block, participants were asked to respond according to the ink color of the word and to ignore its meaning. Physically active seniors showed faster reaction times, lower individual variability in reaction times, and higher accuracy compared to low active seniors, particularly in the high interference block. This result was confirmed in the classic paper-and-pencil version of the Stroop task showing higher interference score in the low active than high active individuals. ERPs revealed a shorter latency of the P2 and generally more negative amplitudes of the fronto-central N2 and N450 components in the high active group compared to the low active group. The amount of interference was negatively correlated with objectively measured fitness and self-reported physical activity. The positive effect of physical fitness on interference processing in the behavioral data was related to N2 and N450 amplitudes. Taken together, this suggests that seniors reporting long-term physical activity may exhibit generally enhanced activity in the frontal cortex which enables more efficient interference resolution in the Stroop task.

Friday, August 07, 2015

The benefits of pupil orientation.

This is kinda neat, from the current issue of Science Magazine:
 
Slit-eyed animals have either vertical or horizontal pupils. It is unclear whether one orientation conveys any sort of competitive advantage over the other, and if so, under what circumstances. Banks et al. suggest that the optics of vertical pupil slits generally benefit predators, whereas the optics of horizontal slits benefit prey. Vertical slits are better for estimating object distance and distances along the ground—perfect for a predator stalking its prey. In contrast, horizontal slits are better for seeing objects on the horizon—ideal for prey seeing an approaching predator and deciding which way to flee.

Are Chatbots destined to become our most sympathetic listeners?

Markoff and Mozur do a fascinating piece in the NYTimes describing how millions of young Chinese use a smartphone program as their intimate companion.
Xiaoice (pronounced Shao-ice) can chat with so many people for hours on end because she is not real. She is a chatbot, a program introduced last year by Microsoft that has become something of a hit in China. It is also making the 2013 film “Her,” in which the actor Joaquin Phoenix plays a character who falls in love with a computer operating system, seem less like science fiction.
The program remembers details from previous exchanges with users, such as a breakup with a girlfriend or boyfriend, and asks in later conversations how the user is feeling. Xiaoice is a text-messaging program; the next version will include a Siri-like voice so people can talk with Xiaoice.
Microsoft has been able to give Xiaoice a more compelling personality and sense of “intelligence” by systematically mining the Chinese Internet for human conversations. The company has developed language processing technology that picks out pairs of questions and answers from actual typed conversations. As a result, Xiaoice has a database of responses that are human and current — she is fond of using emojis, too. (Xiaoice translates roughly to “Little Bing,” after the Microsoft search engine.)
The Microsoft App website lists a few simple English language chat bots, with only a few reviews, nothing like the sophisticated A.I. software being used by the Chinese Microsoft program in Beijing.

Thursday, August 06, 2015

Benefits of High School Music training.

Maybe my avoiding gym classes in high school by being in the marching band and chorus paid off some brain benefits (in addition to my already being a pianist). This this work from Tierney et al. also suggests that the nationwide savaging of high school music curricula is a really bad idea.:
Fundamental changes in brain structure and function during adolescence are well-characterized, but the extent to which experience modulates adolescent neurodevelopment is not. Musical experience provides an ideal case for examining this question because the influence of music training begun early in life is well-known. We investigated the effects of in-school music training, previously shown to enhance auditory skills, versus another in-school training program that did not focus on development of auditory skills (active control). We tested adolescents on neural responses to sound and language skills before they entered high school (pretraining) and again 3 y later. Here, we show that in-school music training begun in high school prolongs the stability of subcortical sound processing and accelerates maturation of cortical auditory responses. Although phonological processing improved in both the music training and active control groups, the enhancement was greater in adolescents who underwent music training. Thus, music training initiated as late as adolescence can enhance neural processing of sound and confer benefits for language skills. These results establish the potential for experience-driven brain plasticity during adolescence and demonstrate that in-school programs can engender these changes.

Wednesday, August 05, 2015

Synchronizing brain theta oscillations strengthens our adaptive behavior control.

Reinhart et al. show that synchronizing low-frequency theta (4-8 Hz) EEG oscillations over the medial-frontal cortex with noninvasive direct current electrical stimulation enhances adaptive control of behavior. :

Significance
The ability to exert control over our behavior is fundamental to human cognition, and is impaired in many neuropsychiatric disorders. Here, we show evidence for the neural mechanisms of adaptive control that distinguish healthy people from people who have schizophrenia. We found that the noninvasive electrical stimulation phase aligns low-frequency brain rhythms and enhances functional connectivity. This brain stimulation modulated the temporal structure of low-frequency oscillations and synchrony, improving adaptive control. Moreover, we found that causal changes in the low-frequency oscillations improved behavioral responses to errors and long-range connectivity at the single-trial level. These results implicate theories of executive control and cortical dysconnectivity, and point to the possible development of nonpharmacological treatment alternatives for neuropsychiatric conditions. 
Abstract
Executive control and flexible adjustment of behavior following errors are essential to adaptive functioning. Loss of adaptive control may be a biomarker of a wide range of neuropsychiatric disorders, particularly in the schizophrenia spectrum. Here, we provide support for the view that oscillatory activity in the frontal cortex underlies adaptive adjustments in cognitive processing following errors. Compared with healthy subjects, patients with schizophrenia exhibited low frequency oscillations with abnormal temporal structure and an absence of synchrony over medial-frontal and lateral-prefrontal cortex following errors. To demonstrate that these abnormal oscillations were the origin of the impaired adaptive control in patients with schizophrenia, we applied noninvasive dc electrical stimulation over the medial-frontal cortex. This noninvasive stimulation descrambled the phase of the low-frequency neural oscillations that synchronize activity across cortical regions. Following stimulation, the behavioral index of adaptive control was improved such that patients were indistinguishable from healthy control subjects. These results provide unique causal evidence for theories of executive control and cortical dysconnectivity in schizophrenia.

Tuesday, August 04, 2015

Another awesome brain video

Science Magazine passes on a video from work reported in Cell Magazine:

New stuff on exercise, brain, and body.

I'll use this post to point readers to several recent interesting articles on physical activity. Hutchinson does a review of work that distinguishes the effect of strength and endurance training versus balance and stability training. The former isn't all that useful without the later, especially in older adults (have you tried standing on one leg with your eyes closed lately?). A German study followed aged adults for 12 months comparing those who did cardiovascular (walking) exercise three times a week, with those who did coordination training. Both groups showed improvement in cognitive functioning, but in different ways. Cardiovascular training was associated with an increased activation of the sensorimotor network, whereas coordination training was associated with increased activation in the visual–spatial network. Mouse studies show that aerobic exercise and strength training trigger brain chemicals that enhance neuron growth and survival, while balance and coordination exercises also recruit higher-level cognitive processes that seem to increase the number of synapses connecting neurons. Work by Kumpulainen et. al. suggests that novelty and unpredictability (as in gymnasts or dancers), rather than repetition (as in endurance athletes), are essential in brain plasticity and engagement.

In another item, Reynolds updates the story on the beneficial effects of intense interval training. Just a few minutes of very intense exercise are much more effective in improving health and cardiovascular fitness than slow and steady repetitive exercise. To try to deal with the problem that most people really don't enjoy zonking themselves out with intense intervals, Bangsbo and collaborators tried a different approach, asking runners to run gently for 30 seconds, then accelerate to a moderate pace for 20 seconds, then sprint as hard as possible for 10 seconds. Repeat five times, rest for a bit, and continue the sequence during a 5-km run. They observed the same beneficial effects on blood pressure and endurance observed with more arduous (several minute) bouts of high intensity training. I tried this 30-20-10 sequence with my favored aerobic exercise, swimming (just counting the intervals to myself made them pass more quickly), and I came out of the routine feeling way more wired than after my usual moderately active swim period.

Monday, August 03, 2015

Brain correlates of the impatience of adolescents.

Teens and young adults show greater impulsivity than children and adults, reflected by increases in emergency room visits, accidents from drug or alcohol use, and increased mortality risk. van den Bos et al. relate this to developmental changes in the structural and functional connectivity of different frontostriatal tracts. Participants made choices between smaller, sooner (SS)  and larger, later (LL) monetary rewards in a delay-discounting task. Accepting a delay for a larger, later reward correlated with prefrontal inhibition of areas in the striatum:
Adolescence is a developmental period associated with an increase in impulsivity. Impulsivity is a multidimensional construct, and in this study we focus on one of the underlying components: impatience. Impatience can result from (i) disregard of future outcomes and/or (ii) oversensitivity to immediate rewards, but it is not known which of these evaluative processes underlie developmental changes. To distinguish between these two causes, we investigated developmental changes in the structural and functional connectivity of different frontostriatal tracts. We report that adolescents were more impatient on an intertemporal choice task and reported less future orientation, but not more present hedonism, than young adults. Developmental increases in structural connectivity strength in the right dorsolateral prefrontal tract were related to increased negative functional coupling with the striatum and an age-related decrease in discount rates. Our results suggest that mainly increased control, and the integration of future-oriented thought, drives the reduction in impatience across adolescence.
This clip from one of the figures shows the relevant brain areas:


By the way, on the subject of adolescents, I'll point to another piece of work by Baker et. al. on developmental changes in brain network hub connectivity in late adolescence

Friday, July 31, 2015

Unlearning social biases during sleep

Feld and Born note that tenacious implicit prejudices of race or gender drive discrimination seen in the rise of nationalistic groups, excessive police violence against minority group members, persisting unequal pay for women, and sexual harassment all across the developed world. They point to work by Hu et al. that shows how such unwanted attitudes may be persistently changed by a social counterbias training when the fresh memories of this training are systematically reactivated during sleep after training. Here is part of their summary:
Sleep, and specifically deep or slow-wave sleep [non–rapid eye movement (REM) sleep], benefits memory formation by reactivating neuronal traces that were formed during the preceding period of wakefulness. This reactivation of specific memories leads to their strengthening and transformation. Such reactivation can be experimentally induced during slow-wave sleep by presenting cues that were present during the prior period of memory acquisition. Initial studies showed that an odor present during learning of object locations enhances these memories when the participant is reexposed to the odor during slow-wave sleep after learning. These findings have been confirmed in numerous studies investigating different memory systems and also when auditory instead of olfactory cues are used. This basic research has firmly established the possibility of influencing sleep to enhance specific newly learned memories by targeted memory reactivation.
The findings by Hu et al. now suggest that this method can also be used to influence implicit attitudes that are known to typically manifest themselves early during childhood and remain very stable into adulthood. Before a 90-min nap, participants underwent training aimed at countering typical implicit gender and racial biases by learning to associate genders and races with opposing attributes; that is, to associate female faces with science-related words and black faces with “good” words. Critically, presentation of the to-be-learned counterassociations was combined with a sound, which served as a cue to promote the reactivation of the newly learned associations during a subsequent nap while the participant was deep in slow-wave sleep. Only when this sound was re-presented during slow-wave sleep did the posttraining reduction in implicit social bias survive and was even evident 1 week later. These findings are all the more convincing as the authors conducted the reactivation step during a 90-min daytime nap. During normal sleep at night, the effects are expected to be even stronger, owing to the generally deeper and longer periods of slow-wave sleep and REM sleep. Additionally, the accompanying neuroendocrine milieu makes nocturnal sleep even more efficient for memory reinforcement.
Previous studies have shown that such targeted reactivation of memory during sleep can effectively extinguish unwanted behavior such as experimentally induced fear in humans. The present study is the first to demonstrate that this method can be used to break long-lived, highly pervasive response habits deeply rooted in memory and thereby influence behavior at an entirely unconscious level.
A caution:
However, Aldous Huxley's description of a dystopian “brave new world” where young children are conditioned to certain values during sleep reminds us that this research also needs to be guided by ethical considerations. Sleep is a state in which the individual is without willful consciousness and therefore vulnerable to suggestion. Beyond that, Hu et al.'s findings highlight the breadth of possible applications to permanently modify any unwanted behavior by targeted memory reactivation during sleep.

Thursday, July 30, 2015

The danger of artificial intelligence is artificial stupidity.

Here are some clips from an interesting Op-Ed piece by Quentin Hardy on artificial intelligence. (And, by the way, a recent issue of Science Magazine has a special section on A.I. with a series of related articles.):
...the real worry...is a computer program rapidly overdoing a single task, with no context. A machine that makes paper clips proceeds unfettered, one example goes, and becomes so proficient that overnight we are drowning in paper clips.
There is little sense among practitioners in the field of artificial intelligence that machines are anywhere close to acquiring the kind of consciousness where they could form lethal opinions about their makers...doomsday scenarios confuse the science with remote philosophical problems about the mind and consciousness...If more people learned how to write software, they’d see how literal-minded these overgrown pencils we call computers actually are.
Deep Learning relies on a hierarchical reasoning technique called neural networks, suggesting the neurons of a brain. Comparing a node in a neural network to a neuron, though, is at best like comparing a toaster to the space shuttle....But machine learning is automation, a better version of what computers have always done. The “learning” is not stored and generalized in the ways that make people smart.
DeepMind made a program that mastered simple video games, but it never took the learning from one game into another. The 22 rungs of a neural net it climbs to figure out what is in a picture do not operate much like human image recognition and are still easily defeated...Moving out of that stupidity to a broader humanlike capability is called “transfer learning.” It is at best in the research phase.
“People in A.I. know that a chess-playing computer still doesn’t yearn to capture a queen,” said Stuart Russell, a professor of Computer Science at the University of California, Berkeley... He seeks mathematical ways to ensure dumb programs don’t conflict with our complex human values.

Wednesday, July 29, 2015

Placebo analgesia reduces empathy for pain.

Fascinating observations from Rütgen et al.. They show that experimental modulation of a first-hand emotion experience also modulates empathy for that emotion experience. This confirms that overlapping neural circuitry for a representation of another's emotion is specifically grounded in neural mechanisms that are also subserving the corresponding first-hand emotion experience, as opposed to unspecific or domain-general neural processes associated with emotion experiences:
Previous research in social neuroscience has consistently shown that empathy for pain recruits brain areas that are also activated during the first-hand experience of pain. This has been interpreted as evidence that empathy relies upon neural processes similar to those underpinning the first-hand experience of emotions. However, whether such overlapping neural activations imply that equivalent neural functions are engaged by empathy and direct emotion experiences remains to be demonstrated. We induced placebo analgesia, a phenomenon specifically modulating the first-hand experience of pain, to test whether this also reduces empathy for pain. Subjective and neural measures of pain and empathy for pain were collected using self-report and event-related potentials (ERPs) while participants underwent painful electrical stimulation or witnessed that another person was undergoing such stimulation. Self-report showed decreased empathy during placebo analgesia, and this was mirrored by reduced amplitudes of the pain-related P2, an ERP component indexing neural computations related to the affective-motivational component of pain. Moreover, these effects were specific for pain, as self-report and ERP measures of control conditions unrelated to pain were not affected by placebo analgesia. Together, the present results suggest that empathy seems to rely on neural processes that are (partially) functionally equivalent to those engaged by first-hand emotion experiences. Moreover, they imply that analgesics may have the unwanted side effect of reducing empathic resonance and concern for others.

Tuesday, July 28, 2015

Dopamine and subjective well-being

Dolan and collaborators note influences of dopamine on emotion and decision making that are distinct from its known role in learning.:
The neuromodulator dopamine has a well established role in reporting appetitive prediction errors that are widely considered in terms of learning. However, across a wide variety of contexts, both phasic and tonic aspects of dopamine are likely to exert more immediate effects that have been less well characterized. Of particular interest is dopamine's influence on economic risk taking and on subjective well-being, a quantity known to be substantially affected by prediction errors resulting from the outcomes of risky choices. By boosting dopamine levels using levodopa (L-DOPA) as human subjects made economic decisions and repeatedly reported their momentary happiness, we show here an effect on both choices and happiness. Boosting dopamine levels increased the number of risky options chosen in trials involving potential gains but not trials involving potential losses. This effect could be better captured as increased Pavlovian approach in an approach–avoidance decision model than as a change in risk preferences within an established prospect theory model. Boosting dopamine also increased happiness resulting from some rewards. Our findings thus identify specific novel influences of dopamine on decision making and emotion that are distinct from its established role in learning.

Monday, July 27, 2015

Brain markers of individual differences in human prosociality.

Sul et al. make the fascinating observation that self-regarding and other-regarding regions of the medial prefrontal cortex show greater segregation in selfish individuals and more overlap in prosocial individuals.
Despite the importance of valuing another person’s welfare for prosocial behavior, currently we have only a limited understanding of how these values are represented in the brain and, more importantly, how they give rise to individual variability in prosociality. In the present study, participants underwent functional magnetic resonance imaging while performing a prosocial learning task in which they could choose to benefit themselves and/or another person. Choice behavior indicated that participants valued the welfare of another person, although less so than they valued their own welfare. Neural data revealed a spatial gradient in activity within the medial prefrontal cortex (MPFC), such that ventral parts predominantly represented self-regarding values and dorsal parts predominantly represented other-regarding values. Importantly, compared with selfish individuals, prosocial individuals showed a more gradual transition from self-regarding to other-regarding value signals in the MPFC and stronger MPFC–striatum coupling when they made choices for another person rather than for themselves. The present study provides evidence of neural markers reflecting individual differences in human prosociality.

Friday, July 24, 2015

Top-down alpha band oscillations optimize visual perception.

Interesting work from Samaha et al.:

Significance
In contrast to canonical, stimulus-driven models of perception, recent proposals argue that perceptual experiences are constructed in an active manner in which top-down influences play a key role. In particular, predictions that the brain makes about the world are incorporated into each perceptual experience. Because forming the appropriate sensory predictions can have a large impact on our visual experiences and visually guided behaviors, a mechanism thought to be disrupted in certain neurological conditions like autism and schizophrenia, an understanding of the neural basis of these predictions is critical. Here, we provide evidence that perceptual expectations about when a stimulus will appear are instantiated in the brain by optimally configuring prestimulus alpha-band oscillations so as to make subsequent processing most efficacious.
Abstract
The physiological state of the brain before an incoming stimulus has substantial consequences for subsequent behavior and neural processing. For example, the phase of ongoing posterior alpha-band oscillations (8–14 Hz) immediately before visual stimulation has been shown to predict perceptual outcomes and downstream neural activity. Although this phenomenon suggests that these oscillations may phasically route information through functional networks, many accounts treat these periodic effects as a consequence of ongoing activity that is independent of behavioral strategy. Here, we investigated whether alpha-band phase can be guided by top-down control in a temporal cueing task. When participants were provided with cues predictive of the moment of visual target onset, discrimination accuracy improved and targets were more frequently reported as consciously seen, relative to unpredictive cues. This effect was accompanied by a significant shift in the phase of alpha-band oscillations, before target onset, toward each participant’s optimal phase for stimulus discrimination. These findings provide direct evidence that forming predictions about when a stimulus will appear can bias the phase of ongoing alpha-band oscillations toward an optimal phase for visual processing, and may thus serve as a mechanism for the top-down control of visual processing guided by temporal predictions.

Thursday, July 23, 2015

Universal features of human music.

I have read through a fascinating paper by Savage et al. that makes a convincing case for statistical universals in the structure and function of human music. I pass on the abstract and a few clips from the text. Motivated readers can request a PDF of the article from me.
Music has been called “the universal language of mankind.” Although contemporary theories of music evolution often invoke various musical universals, the existence of such universals has been disputed for decades and has never been empirically demonstrated. Here we combine a music-classification scheme with statistical analyses, including phylogenetic comparative methods, to examine a well-sampled global set of 304 music recordings. Our analyses reveal no absolute universals but strong support for many statistical universals that are consistent across all nine geographic regions sampled. These universals include 18 musical features that are common individually as well as a network of 10 features that are commonly associated with one another. They span not only features related to pitch and rhythm that are often cited as putative universals but also rarely cited domains including performance style and social context. These cross-cultural structural regularities of human music may relate to roles in facilitating group coordination and cohesion, as exemplified by the universal tendency to sing, play percussion instruments, and dance to simple, repetitive music in groups. Our findings highlight the need for scientists studying music evolution to expand the range of musical cultures and musical features under consideration. The statistical universals we identified represent important candidates for future investigation.
The 18 universal features:
Pitch: Music tends to use discrete pitches (1) to form nonequidistant scales (2) containing seven or fewer scale degrees per octave (3). Music also tends to use descending or arched melodic contours (4) composed of small intervals (5) of less than 750 cents (i.e., a perfect fifth or smaller).
Rhythm: Music tends to use an isochronous beat (6) organized according to metrical hierarchies (7) based on multiples of two or three beats (8)—especially multiples of two beats (9). This beat tends to be used to construct motivic patterns (10) based on fewer than five durational values (11).
Form: Music tends to consist of short phrases (12) less than 9 s long.
Instrumentation: Music tends to use both the voice (13) and (nonvocal) instruments (14), often together in the form of accompanied vocal song.
Performance style: Music tends to use the chest voice (i.e., modal register) (15) to sing words (16), rather than vocables (nonlexical syllables).
Social context: Music tends to be performed predominantly in groups (17) and by males (18). The bias toward male performance is true of singing, but even more so of instrumental performance.
The geographic distribution of the recordings analyzed:

The 304 recordings from the Garland Encyclopedia of World Music show a widespread geographic distribution. They are grouped into nine regions specified a priori by the Encyclopedia’s editors, as color-coded in the legend at bottom: North America (n = 33 recordings), Central/South America (39), Europe (40), Africa (21), the Middle East (35), South Asia (34), East Asia (34), Southeast Asia (14), and Oceania (54).