Uncalculating cooperation is used to signal trustworthiness.

Jordan et al. devise an economic game experiment whose results help to explain a range of puzzling behaviors, such as extreme altruism, the use of ethical principles, and romantic love:

Significance

Human prosociality presents an evolutionary puzzle, and reciprocity has emerged as a dominant explanation: cooperating today can bring benefits tomorrow. Reciprocity theories clearly predict that people should only cooperate when the benefits outweigh the costs, and thus that the decision to cooperate should always depend on a cost–benefit analysis. Yet human cooperation can be very uncalculating: good friends grant favors without asking questions, romantic love “blinds” us to the costs of devotion, and ethical principles make universal moral prescriptions. Here, we provide the first evidence, to our knowledge, that reputation effects drive uncalculating cooperation. We demonstrate, using economic game experiments, that people engage in uncalculating cooperation to signal that they can be relied upon to cooperate in the future.

Abstract

Humans frequently cooperate without carefully weighing the costs and benefits. As a result, people may wind up cooperating when it is not worthwhile to do so. Why risk making costly mistakes? Here, we present experimental evidence that reputation concerns provide an answer: people cooperate in an uncalculating way to signal their trustworthiness to observers. We present two economic game experiments in which uncalculating versus calculating decision-making is operationalized by either a subject’s choice of whether to reveal the precise costs of cooperating (Exp. 1) or the time a subject spends considering these costs (Exp. 2). In both experiments, we find that participants are more likely to engage in uncalculating cooperation when their decision-making process is observable to others. Furthermore, we confirm that people who engage in uncalculating cooperation are perceived as, and actually are, more trustworthy than people who cooperate in a calculating way. Taken together, these data provide the first empirical evidence, to our knowledge, that uncalculating cooperation is used to signal trustworthiness, and is not merely an efficient decision-making strategy that reduces cognitive costs. Our results thus help to explain a range of puzzling behaviors, such as extreme altruism, the use of ethical principles, and romantic love.

A brain area crucial to coping with stress.

Sinha et al. show that “neuroflexibility” in a specific region of our ventromedial prefrontal cortex enhances resilience to stress - an increase in its activity dampens down brain areas initially activated by stress. Subjects showing lower levels of this flexibility exhibited higher levels of maladaptive coping behaviors in real life.

Active coping underlies a healthy stress response, but neural processes supporting such resilient coping are not well-known. Using a brief, sustained exposure paradigm contrasting highly stressful, threatening, and violent stimuli versus nonaversive neutral visual stimuli in a functional magnetic resonance imaging (fMRI) study, we show significant subjective, physiologic, and endocrine increases and temporally related dynamically distinct patterns of neural activation in brain circuits underlying the stress response. First, stress-specific sustained increases in the amygdala, striatum, hypothalamus, midbrain, right insula, and right dorsolateral prefrontal cortex (DLPFC) regions supported the stress processing and reactivity circuit. Second, dynamic neural activation during stress versus neutral runs, showing early increases followed by later reduced activation in the ventrolateral prefrontal cortex (VLPFC), dorsal anterior cingulate cortex (dACC), left DLPFC, hippocampus, and left insula, suggested a stress adaptation response network. Finally, dynamic stress-specific mobilization of the ventromedial prefrontal cortex (VmPFC), marked by initial hypoactivity followed by increased VmPFC activation, pointed to the VmPFC as a key locus of the emotional and behavioral control network. Consistent with this finding, greater neural flexibility signals in the VmPFC during stress correlated with active coping ratings whereas lower dynamic activity in the VmPFC also predicted a higher level of maladaptive coping behaviors in real life, including binge alcohol intake, emotional eating, and frequency of arguments and fights. These findings demonstrate acute functional neuroplasticity during stress, with distinct and separable brain networks that underlie critical components of the stress response, and a specific role for VmPFC neuroflexibility in stress-resilient coping.

To remember something better, wait, then exercise.

Another nice bit on what exercise can do for you.  The abstract from van Dongen et al.:

Highlights

•Performing aerobic exercise 4 hr after learning improved associative memory 

•Exercise at this time also increased hippocampal pattern similarity during retrieval 

•Exercise performed immediately after learning had no effect on memory retention 

•Exercise could have potential as a memory intervention in educational settings

Summary

Persistent long-term memory depends on successful stabilization and integration of new memories after initial encoding. This consolidation process is thought to require neuromodulatory factors such as dopamine, noradrenaline, and brain-derived neurotrophic factor. Without the release of such factors around the time of encoding, memories will decay rapidly. Recent studies have shown that physical exercise acutely stimulates the release of several consolidation-promoting factors in humans, raising the question of whether physical exercise can be used to improve memory retention. Here, we used a single session of physical exercise after learning to exogenously boost memory consolidation and thus long-term memory. Three groups of randomly assigned participants first encoded a set of picture-location associations. Afterward, one group performed exercise immediately, one 4 hr later, and the third did not perform any exercise. Participants otherwise underwent exactly the same procedures to control for potential experimental confounds. Forty-eight hours later, participants returned for a cued-recall test in a magnetic resonance scanner. With this design, we could investigate the impact of acute exercise on memory consolidation and retrieval-related neural processing. We found that performing exercise 4 hr, but not immediately, after encoding improved the retention of picture-location associations compared to the no-exercise control group. Moreover, performing exercise after a delay was associated with increased hippocampal pattern similarity for correct responses during delayed retrieval. Our results suggest that appropriately timed physical exercise can improve long-term memory and highlight the potential of exercise as an intervention in educational and clinical settings.

Distinguishing brain correlations from causes.

Many researchers, even though they know better, fall into the trap of assuming that correlations are causes (i.e., if brain activity X occurs just before or at the same time as action Y, it must be causing Y.) Katz et al. offer a nice example of this in looking at a brain region (the lateral intraparietal (LIP) cortex) whose activity reflects deciding on the direction of a moving set of dots. When this region was inactivated in rhesus macague monkeys performing a motion direction discrimination, it had no effect on decision making performance. But, when area MT (a motion detection area that shows only weak correlations with choices) was inhibited, performance was profoundly impaired. This suggests that larger networks should always be considered even in what seem to be simple decisions. The abstract:

During decision making, neurons in multiple brain regions exhibit responses that are correlated with decisions1. However, it remains uncertain whether or not various forms of decision-related activity are causally related to decision making. Here we address this question by recording and reversibly inactivating the lateral intraparietal (LIP) and middle temporal (MT) areas of rhesus macaques performing a motion direction discrimination task. Neurons in area LIP exhibited firing rate patterns that directly resembled the evidence accumulation process posited to govern decision making, with strong correlations between their response fluctuations and the animal’s choices. Neurons in area MT, in contrast, exhibited weak correlations between their response fluctuations and choices, and had firing rate patterns consistent with their sensory role in motion encoding. The behavioural impact of pharmacological inactivation of each area was inversely related to their degree of decision-related activity: while inactivation of neurons in MT profoundly impaired psychophysical performance, inactivation in LIP had no measurable impact on decision-making performance, despite having silenced the very clusters that exhibited strong decision-related activity. Although LIP inactivation did not impair psychophysical behaviour, it did influence spatial selection and oculomotor metrics in a free-choice control task. The absence of an effect on perceptual decision making was stable over trials and sessions and was robust to changes in stimulus type and task geometry, arguing against several forms of compensation. Thus, decision-related signals in LIP do not appear to be critical for computing perceptual decisions, and may instead reflect secondary processes. Our findings highlight a dissociation between decision correlation and causation, showing that strong neuron-decision correlations do not necessarily offer direct access to the neural computations underlying decisions.

Competition does not improve quality of work.

I have always been phobic about competition, especially in my scientific laboratory work, because I could feel its toxic effects on my risk taking, spontaneity and creativity. The reason that I made some useful contributions to understanding the chemistry of how we see is that I chose to emphasize questions and areas that were not in the current arenas of competition. I also felt the peer review processes involved were frequently biased (I served as a grant peer reviewer for many years.)  Balietti et al. design a laboratory experiment that produces results exactly matching my own experience:

Significance

Competition is an essential mechanism in increasing the effort and performance of human groups in real life. However, competition has side effects: it can be detrimental to creativity and reduce cooperation. We conducted an experiment called the Art Exhibition Game to investigate the effect of competitive incentives in environments where the quality of creative products and the amount of innovation allowed are decided through peer review. Our approach is general and can provide insights in domains such as clinical evaluations, scientific admissibility, and science funding. Our results show that competition leads to more innovation but also to more unfair reviews and to a lower level of agreement between reviewers. Moreover, competition does not improve the average quality of published works.  

Abstract

To investigate the effect of competitive incentives under peer review, we designed a novel experimental setup called the Art Exhibition Game. We present experimental evidence of how competition introduces both positive and negative effects when creative artifacts are evaluated and selected by peer review. Competition proved to be a double-edged sword: on the one hand, it fosters innovation and product diversity, but on the other hand, it also leads to more unfair reviews and to a lower level of agreement between reviewers. Moreover, an external validation of the quality of peer reviews during the laboratory experiment, based on 23,627 online evaluations on Amazon Mechanical Turk, shows that competition does not significantly increase the level of creativity. Furthermore, the higher rejection rate under competitive conditions does not improve the average quality of published contributions, because more high-quality work is also rejected. Overall, our results could explain why many ground-breaking studies in science end up in lower-tier journals. Differences and similarities between the Art Exhibition Game and scholarly peer review are discussed and the implications for the design of new incentive systems for scientists are explained.

Turn-taking skills unique to humans?

In yet another "humans are unique with respect to...." type article Melis, Tomasello and collaborators do experiments showing that humans differ in their ability to carry out long-term collaborative relationships that involve taking turns. I've been reading de Waal's recent book "Are we smart enough to know how smart animals are?" (which I highly recommend), which suggests that the "unique to humans" implicit in the title of the article of the article may not be appropriate, for the article demonstrates a more 'advanced' behavior in humans only in a specific paradyme involving just the two species. Potential turn taking behavior in other social animals, invertebrates as well as vertebrates, is still a possibility. The experiments:

...gave pairs of 3- and 5-year-old children and chimpanzees a collaboration task in which equal rewards could be obtained only if the members of a pair worked together first to reward one and then to reward the other. Neither species had previously been tested in a paradigm in which partners can distribute collaboratively produced rewards in “fair” ways only by taking turns being the sole beneficiary.

Here is their abstract:

Long-term collaborative relationships require that any jointly produced resources be shared in mutually satisfactory ways. Prototypically, this sharing involves partners dividing up simultaneously available resources, but sometimes the collaboration makes a resource available to only one individual, and any sharing of resources must take place across repeated instances over time. Here, we show that beginning at 5 years of age, human children stabilize cooperation in such cases by taking turns across instances of obtaining a resource. In contrast, chimpanzees do not take turns in this way, and so their collaboration tends to disintegrate over time. Alternating turns in obtaining a collaboratively produced resource does not necessarily require a prosocial concern for the other, but rather requires only a strategic judgment that partners need incentives to continue collaborating. These results suggest that human beings are adapted for thinking strategically in ways that sustain long-term cooperative relationships and that are absent in their nearest primate relatives.

Zapping your brain at home.

Mindblog has done a number of posts on transcranial electrical stimulation, usually reporting some beneficial cognitive or emotional effects (enter 'transcranial in the mindblog search box to see some of these). Because the technique requires only a 9 volt battery and a couple of wires, do it yourself (D.I.Y) kits have been marketed by a number of websites, but in general professional cognitive scientists caution against home brew science efforts because of potential deleterious effects of brain stimulation (though none have been reported). A recent Gray Matter piece by Anna Wexler reports her study over the past three years of D.I.Y. brain stimulators:

Their conflict with neuroscientists offers a fascinating case study of what happens when experimental tools normally kept behind the closed doors of academia — in this case, transcranial direct current stimulation — are appropriated for use outside them...To date, more than 1,000 peer-reviewed studies of the technique have been published. Studies have suggested, among other things, that the stimulation may be beneficial for treating problems like depression and chronic pain as well as enhancing cognition and learning in healthy individuals.

(I should point out my post noting a review by Farah that references one meta-analysis of the literature that does not support reported cognitive effects.)

Home use remains a subculture, part of the contemporary movement to “hack” one’s body — using supplements, brain-training games and self-tracking devices — to optimize productivity...I have conducted long interviews with dozens of D.I.Y. stimulators, both in person and via Skype; collected hundreds of questionnaire responses; and tracked online forums, websites, blogs and other platforms on which practitioners communicate. I’ve found that they are — for the most part — astute, inventive and resourceful....I’ve found (as I reported last year in The Journal of Medical Ethics) that users adhere to many of the protocols used in scientific studies.

The growth of D.I.Y. brain stimulation stems in part from a larger frustration with the exclusionary institutions of modern medicine, such as the exorbitant price of pharmaceuticals and the glacial pace at which new therapies trickle down to patients. For people without an institutional affiliation, even reading a journal article can be prohibitively expensive.

As neuroscientists continue to conduct brain stimulation experiments, publish results in journals and hold conferences, the D.I.Y. practitioners have remained quiet downstream listeners, blogging about scientists’ experiments, posting unrestricted versions of journal articles and linking to videos of conference talks. Some practitioners create their own manuals and guides based on published papers.

Added note: Want a brain stimulation conference? Check this out.

Worldwide internet access from light based wireless communication

Under the "random curious stuff" category in MindBlog's subtitle, I want to point to this NYTimes piece that fascinated me by using some simple analogies to explain complex technical issues. The work is a prelude to providing internet access anywhere on the planet, from the skies, using drones.:

In a paper published Tuesday in Optica, researchers from Internet.org’s Connectivity Lab have outlined a new type of light detector that can be used for free-space optical communication, a communication technique that uses light to send data wirelessly.

Free-space optical communication works by encoding communication signals in laser beams. Transmitters on the ground or in satellites shoot that light through the air to receivers that can decode the data. (To understand this on simple terms, think of encoding and sending information through morse code using a flashlight.)

...many free-space optical communication systems use smaller receivers with complex pointing and tracking systems. Because laser beams are narrow and travel in straight lines from point A to point B, these receivers have to continuously maneuver to catch laser beams head-on...Imagine trying to water a small potted plant with a water gun from different angles...To maximize the amount of water you catch, you have to constantly move the pot around.

The Facebook researchers’ solution to this problem is a light detector that doesn’t need pointing and tracking, but still allows for fast transmission...Facebook’s detector contains a spherical bundle of special fluorescent fibers. The bundle, somewhere between the size of a golf ball and tennis ball, is able to absorb blue laser light from any direction and re-emit it as green light. Because that green light is diffuse, it can then be funneled to a small receiver that converts the light back to data...imagine that instead of a water gun, you’re pointing a blow dart gun at a water balloon attached to a funnel over the potted plant. As soon as you hit the balloon, it pops and releases water. With the addition of the balloon, you’ve eliminated the need to move the pot around. You can shoot at the water balloon from any direction, and the plant will get watered.

Facebook’s new detector is able to achieve fast data rates of two gigabits per second — several orders of magnitude higher than those from radio frequencies — because light has a higher frequency than radio waves, and because the fluorescence process is fast. Free-space optical communication can also carry more information than radio communication, and is more secure because narrow laser beams are harder to intercept than wide radio waves.

The technology fits in with Facebook’s plans to beam internet access down from the skies using drones.

Abstract thinking in newborn ducklings!

Martinho and Kacelnik have shown that duckings imprint on the relational concept of "same or different." From Wasserman's perspective on the work:

Adhering to the adage that “actions speak more loudly than words,” scientists are deploying powerful behavioral tests that provide animals with nonverbal ways to reveal their intelligence to us. Although animals may not be able to speak, studying their behavior may be a suitable substitute for assaying their thoughts, and this in turn may allow us to jettison the stale canard that thought without language is impossible. Following this behavioral approach and using the familiar social learning phenomenon of imprinting, Martinho and Kacelnik report that mallard ducklings preferentially followed a novel pair of objects that conformed to the learned relation between a familiar pair of objects. Ducklings that had earlier been exposed to a pair of identical objects preferred a pair of identical objects to a pair of nonidentical objects; other ducklings that had been exposed to a pair of nonidentical objects preferred a pair of nonidentical objects to a pair of identical objects. Because the testing objects were decidedly unlike the training objects, Martinho and Kacelnik concluded that the ducklings had effectively understood the abstract concepts of “same” and “different.”

A duckling in the testing arena approaches a stimulus pair composed of “different” shapes.

This study is important for at least three reasons. First, it indicates that animals not generally believed to be especially intelligent are capable of abstract thought. Second, even very young animals may be able to display behavioral signs of abstract thinking. And, third, reliable behavioral signs of abstract relational thinking can be obtained without deploying explicit reward-and-punishment procedures.

Brain scans are prone to false positives.

An analysis by Eklund et al. has raised serious doubts about positive correlations reported in many of the 40,000 fMRI studies published in the last 2 decades (think of all those ‘This is your brain on politics’ type articles).

Significance

Functional MRI (fMRI) is 25 years old, yet surprisingly its most common statistical methods have not been validated using real data. Here, we used resting-state fMRI data from 499 healthy controls to conduct 3 million task group analyses. Using this null data with different experimental designs, we estimate the incidence of significant results. In theory, we should find 5% false positives (for a significance threshold of 5%), but instead we found that the most common software packages for fMRI analysis (SPM, FSL, AFNI) can result in false-positive rates of up to 70%. These results question the validity of some 40,000 fMRI studies and may have a large impact on the interpretation of neuroimaging results.

Abstract

The most widely used task functional magnetic resonance imaging (fMRI) analyses use parametric statistical methods that depend on a variety of assumptions. In this work, we use real resting-state data and a total of 3 million random task group analyses to compute empirical familywise error rates for the fMRI software packages SPM, FSL, and AFNI, as well as a nonparametric permutation method. For a nominal familywise error rate of 5%, the parametric statistical methods are shown to be conservative for voxelwise inference and invalid for clusterwise inference. Our results suggest that the principal cause of the invalid cluster inferences is spatial autocorrelation functions that do not follow the assumed Gaussian shape. By comparison, the nonparametric permutation test is found to produce nominal results for voxelwise as well as clusterwise inference. These findings speak to the need of validating the statistical methods being used in the field of neuroimaging.

Added note: Check out this NYTimes piece on these issues.

A must see Rube Goldberg machine

The intractability of implicit beliefs

Caoa and Banaji in the Harvard Psychology Dept. introduce their study:

Imagine meeting Jonathan and Elizabeth. One person is a doctor. The other is a nurse. Who is the doctor? Or imagine that an employer is deciding to hire either Colin or Jamaal. A background check will reveal that one person has a violent felony on his record and therefore will not be hired. Who is the violent felon? Before individuating facts are learned, when only gender or race is known, one of two principles can guide beliefs.

The first, which we call the base rate principle, supports the belief that Jonathan is the doctor and Jamaal is the violent felon. If ignoring base rates is considered an error, then one must realize that doctors are more likely to be men than women and people with violent felonies on their record are more likely to be Black than White. In fact, because group membership contains useful information for deciding whether an individual has a certain attribute, stereotypes have been conceptualized as base rates. Moreover, decision theorists have shown that base rates are critical ingredients for making predictions, as neglecting base rates will cause predictions to deviate from what is statistically likely.

Using these base rates, however, is inconsistent with a second principle that we call the fairness principle. By this account, it is morally proper to assume a fair coin, so to speak. Jonathan and Elizabeth are equally likely to be the doctor and Colin and Jamaal are equally likely to have a violent felony on their record. Motivated by egalitarian values, many people believe that base rates cannot and should not be used to make such predictions. In fact, the value of fairness is deeply woven into many legal systems. American courts have rejected the use of base rates to determine guilt, and the European Union has banned gender-based insurance premiums.

In the present work, we assess which principle guides beliefs before individuating facts are learned. Given only information about gender, do beliefs favor Jonathan to be the doctor or both Jonathan and Elizabeth equally to be the doctor? We then assess if the base rate and fairness principles are set aside after individuating facts are learned. Given facts that make abundantly clear who is—and who is not—the doctor, do beliefs align with the facts?

Here is the abstract summarizing their findings:

Meet Jonathan and Elizabeth. One person is a doctor and the other is a nurse. Who is the doctor? When nothing else is known, the base rate principle favors Jonathan to be the doctor and the fairness principle favors both individuals equally. However, when individuating facts reveal who is actually the doctor, base rates and fairness become irrelevant, as the facts make the correct answer clear. In three experiments, explicit and implicit beliefs were measured before and after individuating facts were learned. These facts were either stereotypic (e.g., Jonathan is the doctor, Elizabeth is the nurse) or counterstereotypic (e.g., Elizabeth is the doctor, Jonathan is the nurse). Results showed that before individuating facts were learned, explicit beliefs followed the fairness principle, whereas implicit beliefs followed the base rate principle. After individuating facts were learned, explicit beliefs correctly aligned with stereotypic and counterstereotypic facts. Implicit beliefs, however, were immune to counterstereotypic facts and continued to follow the base rate principle. Having established the robustness and generality of these results, a fourth experiment verified that gender stereotypes played a causal role: when both individuals were male, explicit and implicit beliefs alike correctly converged with individuating facts. Taken together, these experiments demonstrate that explicit beliefs uphold fairness and incorporate obvious and relevant facts, but implicit beliefs uphold base rates and appear relatively impervious to counterstereotypic facts.

Our sociability correlates with epigenetic oxytocin gene modifications.

From Haas et al.:

 Significance

Elucidating the genetic and biological substrates of social behavior serves to advance the way basic human nature is understood and improves the way genetic and biological markers can be used to prevent, diagnose, and treat people with impairments in social cognition and behavior. This study shows that epigenetic modification of the structural gene for oxytocin (OXT) is an important factor associated with individual differences in social processing, including self-report, behavior, and brain function and structure in humans.

Abstract

Across many mammalian species there exist genetic and biological systems that facilitate the tendency to be social. Oxytocin is a neuropeptide involved in social-approach behaviors in humans and others mammals. Although there exists a large, mounting body of evidence showing that oxytocin signaling genes are associated with human sociability, very little is currently known regarding the way the structural gene for oxytocin (OXT) confers individual differences in human sociability. In this study, we undertook a comprehensive approach to investigate the association between epigenetic modification of OXT via DNA methylation, and overt measures of social processing, including self-report, behavior, and brain function and structure. Genetic data were collected via saliva samples and analyzed to target and quantify DNA methylation across the promoter region of OXT. We observed a consistent pattern of results across sociability measures. People that exhibit lower OXT DNA methylation (presumably linked to higher OXT expression) display more secure attachment styles, improved ability to recognize emotional facial expressions, greater superior temporal sulcus activity during two social-cognitive functional MRI tasks, and larger fusiform gyrus gray matter volume than people that exhibit higher OXT DNA methylation. These findings provide empirical evidence that epigenetic modification of OXT is linked to several overt measures of sociability in humans and serve to advance progress in translational social neuroscience research toward a better understanding of the evolutionary and genetic basis of normal and abnormal human sociability.

Cultural differences in music perception

McDermott et al. find that the isolated Tsimane people, who live in the Amazonian rainforest in northwest Bolivia, have no preference for for consonance over dissonance.

Music is present in every culture, but the degree to which it is shaped by biology remains debated. One widely discussed phenomenon is that some combinations of notes are perceived by Westerners as pleasant, or consonant, whereas others are perceived as unpleasant, or dissonant. The contrast between consonance and dissonance is central to Western music and its origins have fascinated scholars since the ancient Greeks. Aesthetic responses to consonance are commonly assumed by scientists to have biological roots11, and thus to be universally present in humans. Ethnomusicologists and composers, in contrast, have argued that consonance is a creation of Western musical culture. The issue has remained unresolved, partly because little is known about the extent of cross-cultural variation in consonance preferences18. Here we report experiments with the Tsimane’—a native Amazonian society with minimal exposure to Western culture—and comparison populations in Bolivia and the United States that varied in exposure to Western music. Participants rated the pleasantness of sounds. Despite exhibiting Western-like discrimination abilities and Western-like aesthetic responses to familiar sounds and acoustic roughness, the Tsimane’ rated consonant and dissonant chords and vocal harmonies as equally pleasant. By contrast, Bolivian city- and town-dwellers exhibited significant preferences for consonance, albeit to a lesser degree than US residents. The results indicate that consonance preferences can be absent in cultures sufficiently isolated from Western music, and are thus unlikely to reflect innate biases or exposure to harmonic natural sounds. The observed variation in preferences is presumably determined by exposure to musical harmony, suggesting that culture has a dominant role in shaping aesthetic responses to music.

Oxytocin both bonds and divides the sexes.

From Gao et al.:

Facilitation of social attraction and bonding by the evolutionarily conserved neuropeptide oxytocin is well-established in female mammals. However, accumulating behavioral evidence suggests that oxytocin may have evolved sex-specific functional roles in the domain of human social cognition. A critical question is how oxytocin differentially modulates neural processing of social information in men and women, leading to divergent behavioral responses. Here we show that intranasal oxytocin treatment produces sex- and valence-dependent increases in amygdala activation when women view individuals identified as praising others but in men those who criticize them. Women subsequently show increased liking for the faces of these individuals, whereas in men it is reduced. Thus, oxytocin may act differentially via the amygdala to enhance the salience of positive social attributes in women but negative ones in men. We hypothesize that oxytocin may have evolved different but complementary roles to help ensure successful reproduction by encouraging mothers to promote a prosocial rearing environment for offspring and fathers to protect against antisocial influences.

Placebo effects in brain training

Foroughi et al. address the question of whether our desire to become smarter may blind us to the role of placebo effects in brain training regimes. They found that few published articles on cognitive training provide details regarding participant recruitment... whether participants were recruited overtly [e.g., “sign up for a brain training study” ] or covertly [e.g., “did not inform subjects that they were participating in a training study”]. The authors:

...designed a procedure to intentionally induce a placebo effect via overt recruitment. Our recruitment targeted two populations of participants using different advertisements varying in the degree to which they evoked an expectation of cognitive improvement. Once participants self-selected into the two groups, they completed two pretraining fluid intelligence tests followed by 1 h of cognitive training and then completed two posttraining fluid intelligence tests on the following day. Two individual difference metrics regarding beliefs about cognition and intelligence were also collected as potential moderators. The researchers who interacted with participants were blind to the goal of the experiment and to the experimental condition. Aside from their means of recruitment, all participants completed identical cognitive-training experiments. All participants read and signed an informed consent form before beginning the experiment.

Here are their summaries:

Significance

Placebo effects pose problems for some intervention studies, particularly those with no clearly identified mechanism. Cognitive training falls into that category, and yet the role of placebos in cognitive interventions has not yet been critically evaluated. Here, we show clear evidence of placebo effects after a brief cognitive training routine that led to significant fluid intelligence gains. Our goal is to emphasize the importance of ruling out alternative explanations before attributing the effect to interventions. Based on our findings, we recommend that researchers account for placebo effects before claiming treatment effects.

Abstract

Although a large body of research shows that general cognitive ability is heritable and stable in young adults, there is recent evidence that fluid intelligence can be heightened with cognitive training. Many researchers, however, have questioned the methodology of the cognitive-training studies reporting improvements in fluid intelligence: specifically, the role of placebo effects. We designed a procedure to intentionally induce a placebo effect via overt recruitment in an effort to evaluate the role of placebo effects in fluid intelligence gains from cognitive training. Individuals who self-selected into the placebo group by responding to a suggestive flyer showed improvements after a single, 1-h session of cognitive training that equates to a 5- to 10-point increase on a standard IQ test. Controls responding to a nonsuggestive flyer showed no improvement. These findings provide an alternative explanation for effects observed in the cognitive-training literature and the brain-training industry, revealing the need to account for confounds in future research.

Consciousness is the brain messing with itself.

George Johnson does a nice summary of some current ideas on what consciousness is that were discussed at a recent symposium (live stream here) at The New York Academy of Sciences. He notes for example Graziano's ideas that I have previously reviewed on MindBlog:

Descartes’s notion of dualism — mind and body as separate things — has long receded from science. The challenge now is to explain how the inner world of consciousness arises from the flesh of the brain.

Michael Graziano, a neuroscientist at Princeton University, suggested to the audience that consciousness is a kind of con game the brain plays with itself. The brain is a computer that evolved to simulate the outside world. Among its internal models is a simulation of itself — a crude approximation of its own neurological processes... The result is an illusion. Instead of neurons and synapses, we sense a ghostly presence — a self — inside the head. But it’s all just data processing...“The machine mistakenly thinks it has magic inside it,” Dr. Graziano said. And it calls the magic consciousness.

It’s not the existence of this inner voice he finds mysterious. “The phenomenon to explain,” he said, “is why the brain, as a machine, insists it has this property that is nonphysical.”

Johnson notes other ideas aired at the symposium, such as "the centuries-old doctrine of panpsychism — the idea that consciousness is universal, existing as some kind of mind stuff inside molecules and atoms."

Insurance makes sellers of services dishonest.

This piece from Kerschbamer et al. really resonates with my experiences in Florida, scam central for health insurance fraud:

Honesty is a fundamental pillar for cooperation in human societies and thus for their economic welfare. However, humans do not always act in an honest way. Here, we examine how insurance coverage affects the degree of honesty in credence goods markets. Such markets are plagued by strong incentives for fraudulent behavior of sellers, resulting in estimated annual costs of billions of dollars to customers and the society as a whole. Prime examples of credence goods are all kinds of repair services, the provision of medical treatments, the sale of software programs, and the provision of taxi rides in unfamiliar cities. We examine in a natural field experiment how computer repair shops take advantage of customers’ insurance for repair costs. In a control treatment, the average repair price is about EUR 70, whereas the repair bill increases by more than 80% when the service provider is informed that an insurance would reimburse the bill. Our design allows decomposing the sources of this economically impressive difference, showing that it is mainly due to the overprovision of parts and overcharging of working time. A survey among repair shops shows that the higher bills are mainly ascribed to insured customers being less likely to be concerned about minimizing costs because a third party (the insurer) pays the bill. Overall, our results strongly suggest that insurance coverage greatly increases the extent of dishonesty in important sectors of the economy with potentially huge costs to customers and whole economies.

Who blames the victim?

Niemi and Young ask

What determines whether someone feels sympathy or scorn for the victim of a crime? Is it a function of political affiliation? Of gender? Of the nature of the crime? (If you are mugged on a midnight stroll through the park, some people will feel compassion for you, while others will admonish you for being there in the first place. If you are raped by an acquaintance after getting drunk at a party, some will be moved by your misfortune, while others will ask why you put yourself in such a situation.) Their experiments find that the critical factor lies in a particular set of moral values. Their experiments show that the more strongly you privilege loyalty, obedience and purity — as opposed to values such as care and fairness — the more likely you are to blame the victim.

The abstract:

Why do victims sometimes receive sympathy for their suffering and at other times scorn and blame? Here we show a powerful role for moral values in attitudes toward victims. We measured moral values associated with unconditionally prohibiting harm (“individualizing values”) versus moral values associated with prohibiting behavior that destabilizes groups and relationships (“binding values”: loyalty, obedience to authority, and purity). Increased endorsement of binding values predicted increased ratings of victims as contaminated (Studies 1-4); increased blame and responsibility attributed to victims, increased perceptions of victims’ (versus perpetrators’) behaviors as contributing to the outcome, and decreased focus on perpetrators (Studies 2-3). Patterns persisted controlling for politics, just world beliefs, and right-wing authoritarianism. Experimentally manipulating linguistic focus off of victims and onto perpetrators reduced victim blame. Both binding values and focus modulated victim blame through victim responsibility attributions. Findings indicate the important role of ideology in attitudes toward victims via effects on responsibility attribution.

Social support, stress, and the aging brain

Sherman et al. find that the volume of the amygdala in older adults (a center for stress responses) is positively correlated with stress and negatively correlated with social support, these two effects being apparently independent of each other.

Social support benefits health and well-being in older individuals, however the mechanism remains poorly understood. One proposal, the stress-buffering hypothesis states social support ‘buffers’ the effects of stress on health. Alternatively, the main effect hypothesis suggests social support independently promotes health. We examined the combined association of social support and stress on the aging brain. Forty healthy older adults completed stress questionnaires, a social network interview and structural MRI to investigate the amygdala-medial prefrontal cortex circuitry, which is implicated in social and emotional processing and negatively affected by stress. Social support was positively correlated with right medial prefrontal cortical thickness while amygdala volume was negatively associated with social support and positively related to stress. We examined whether the association between social support and amygdala volume varied across stress level. Stress and social support uniquely contribute to amygdala volume, which is consistent with the health benefits of social support being independent of stress.