Mindfulness neuroscience

The journal Social Cognitive and Affective Neuroscience has released an issue devoted to studies of brain correlates of different kinds of meditation. One article, on compassion or loving-kindness meditation, is open access. For me, the crucial article is the last one, written by a senior guru of the brain imaging field, Michael Posner, and his colleague Yi-Yuan Tang, outlining theoretical and methodological issues in the field. They note that reviews of the field have:

..summarized four components of how mindfulness meditation may work: (i) attention regulation, (ii) body awareness, (iii) emotion regulation (including reappraisal, exposure, extinction and reconsolidation) and (iv) change in perspective on the self. The authors indicate that mindfulness practice comprises a process of enhanced self-regulation that can be differentiated into distinct but interrelated components. While these components are a start, future empirical work should identify additional components of mindfulness and establish to what extent the components involve distinct mechanisms.

Many studies have difficulties with appropriate control and comparison subjects:

Different control and comparison groups have been used in mindfulness research, such as waiting lists, active control groups and interventions designed to match the non-specific effects of mindfulness practices, such as trainer’s confidence, expectancy effects and group support... Ideally, participants would be randomly assigned to condition, and the conditions would be matched with the many non-specific factors that have been found to produce beneficial change... Random assignment allows the changes observed in mindfulness research to be reasonably attributed to the active ingredient of mindfulness practice per se rather than to pre-existing differences in the experimental and control groups. Therefore, moving the field will require the use of rigorous comparison conditions to which participants are randomly assigned.

In long-term studies, an active control is not possible. In studies of long-term practitioners such as monks with many thousands of hours of practice, it is challenging to find even a matched control group. We don’t know how the monks differed before meditation practice and other factors including the environment and low stress, which differ from any ‘matched’ control group.

Other issues are that the various studies employ different mindfulness techniques, stages of practice, or duration of training. (Motivated readers can request a copy of his article from me.)

The power of concentration

I've been meaning to pass on this review by Konnikova on the salutary effects of mindfulness and concentration. It pulls together a number of observations that I have noted in previous MindBlog posts. Here are a few clips:

...mindfulness is less about spirituality and more about concentration: the ability to quiet your mind, focus your attention on the present, and dismiss any distractions that come your way...In 2011, researchers from the University of Wisconsin demonstrated that daily meditation-like thought could shift frontal brain activity toward a pattern that is associated with what cognitive scientists call positive, approach-oriented emotional states — states that make us more likely to engage the world rather than to withdraw from it...

An exercise in mindfulness can also help with that plague of modern existence: multitasking...researchers led by a team from the University of Washington examined the effects of meditation training on multitasking in a real-world setting. They asked a group of human resources professionals to engage in the type of simultaneous planning they did habitually... After the multitasking free-for-all, participants were divided into three groups: one was assigned to an eight-week meditation course (two hours of instruction, weekly); another group didn’t take the course at first, but took it later; and the last group took an eight-week course in body relaxation. Everyone was put through a second round of frenzy...The only participants to show improvement were those who had received the mindfulness training.Not only did they report fewer negative emotions at the end of the assignment, but their ability to concentrate improved significantly. They could stay on task longer and they switched between tasks less frequently.

In recent years, mindfulness has been shown to improve connectivity inside our brain’s attentional networks, as well as between attentional and medial frontal regions — changes that save us from distraction. Mindfulness, in other words, helps our attention networks communicate better and with fewer interruptions than they otherwise would...In 2006, a team of psychologists demonstrated that the neural activation patterns of older adults (specifically, activation in the prefrontal cortex), began to resemble those of much younger subjects after just five one-hour training sessions on a task of attentional control. Their brains became more efficient at coordinating multiple tasks — and the benefit transferred to untrained activities, suggesting that it was symptomatic of general improvement.

Similar changes have been observed in the default network (the brain’s resting-state activity). In 2012, researchers from Ohio State University demonstrated that older adults who scored higher on mindfulness scales had increased connectivity in their default networks, specifically in two of the brain’s major information processing hubs. And while we already know that this kind of increased connectivity is a very good thing, there’s more to these particular results. The precise areas that show increased connectivity with mindfulness are also known to be pathophysiological sites of Alzheimer’s disease.

Self affirmation enhances responsiveness to errors.

Legault et al. note brain responses that correlate with augmented attention and emotional receptivity to performance errors caused by enhanced self affirmation. The experiments used the usual group of undergraduate psychology students, who were split into two groups given writing exercises designed to either enhance or undermine self-affirmation. Both groups then performed a simple go, no-go exercise, with errors getting negative feedback. EEG recordings were made during this exercise. Here is their summary extract:

Self-affirmation produces large effects: Even a simple reminder of one’s core values reduces defensiveness against threatening information. But how, exactly, does self-affirmation work? We explored this question by examining the impact of self-affirmation on neurophysiological responses to threatening events. We hypothesized that because self-affirmation increases openness to threat and enhances approachability of unfavorable feedback, it should augment attention and emotional receptivity to performance errors. We further hypothesized that this augmentation could be assessed directly, at the level of the brain. We measured self-affirmed and nonaffirmed participants’ electrophysiological responses to making errors on a task. As we anticipated, self-affirmation elicited greater error responsiveness than did nonaffirmation, as indexed by the error-related negativity, a neural signal of error monitoring. Self-affirmed participants also performed better on the task than did nonaffirmed participants. We offer novel brain evidence that self-affirmation increases openness to threat and discuss the role of error detection in the link between self-affirmation and performance.

Music and movement: shared dynamic structure in universal expressions of emotion

Sievers et al. do a fascinating analysis. They designed an ingenious computer program that used slider bars to adjust a music player or a bouncing ball with varying rate, jitter (regularity of rate), direction, step size, and dissonance/visual spikiness. Participants were instructed to take as much time as needed to set the sliders in the program to express five emotions: “angry,” “happy,” “peaceful,” “sad,” and “scared.” One set of participants was instructed to move sliders to express the emotion with the moving ball, then other set told to move the sliders to use music to express the emotion. U.S. college students were one experimental group, the other was a culturally isolated Kreug ethnic minority in northern Cambodia with music formally dissimilar to Western music: no system of vertical pitch relations equivalent to Western tonal harmony, constructed using different scales and tunings, and performed on morphologically dissimilar instruments. Here is the authors' summary abstract:

Music moves us. Its kinetic power is the foundation of human behaviors as diverse as dance, romance, lullabies, and the military march. Despite its significance, the music-movement relationship is poorly understood. We present an empirical method for testing whether music and movement share a common structure that affords equivalent and universal emotional expressions. Our method uses a computer program that can generate matching examples of music and movement from a single set of features: rate, jitter (regularity of rate), direction, step size, and dissonance/visual spikiness. We applied our method in two experiments, one in the United States and another in an isolated tribal village in Cambodia. These experiments revealed three things: (i) each emotion was represented by a unique combination of features, (ii) each combination expressed the same emotion in both music and movement, and (iii) this common structure between music and movement was evident within and across cultures.

The End of History Illusion.

The Jan 4 issue of Science has an interested article by Quoidbach et al. on our perception of how much we changed in the past decade and how much we expect to change in the next. Here is some context from their introduction:

At every stage of life, people make decisions that profoundly influence the lives of the people they will become—and when they finally become those people, they aren’t always thrilled about it. Young adults pay to remove the tattoos that teenagers paid to get, middle-aged adults rush to divorce the people whom young adults rushed to marry, and older adults visit health spas to lose what middle-aged adults visited restaurants to gain. Why do people so often make decisions that their future selves regret? One possibility is that people have a fundamental misconception about their future selves. Time is a powerful force that transforms people’s preferences, reshapes their values, and alters their personalities, and we suspect that people generally underestimate the magnitude of those changes. In other words, people may believe that who they are today is pretty much who they will be tomorrow, despite the fact that it isn’t who they were yesterday. In the studies we describe here, we showed that people expect to change little in the future, despite knowing that they have changed a lot in the past, and that this tendency bedevils their decision-making. We call this tendency to underestimate the magnitude of future change the “end of history illusion.”

And here is their summary and discussion:

Across six studies of more than 19,000 participants, we found consistent evidence to indicate that people underestimate how much they will change in the future, and that doing so can lead to suboptimal decisions. Although these data cannot tell us what causes the end of history illusion, two possibilities seem likely. First, most people believe that their personalities are attractive, their values admirable, and their preferences wise (10); and having reached that exalted state, they may be reluctant to entertain the possibility of change. People also like to believe that they know themselves well (11), and the possibility of future change may threaten that belief. In short, people are motivated to think well of themselves and to feel secure in that understanding, and the end of history illusion may help them accomplish these goals.

Second, there is at least one important difference between the cognitive processes that allow people to look forward and backward in time (12). Prospection is a constructive process, retrospection is a reconstructive process, and constructing new things is typically more difficult than reconstructing old ones (13, 14). The reason this matters is that people often draw inferences from the ease with which they can remember or imagine (15, 16). If people find it difficult to imagine the ways in which their traits, values, or preferences will change in the future, they may assume that such changes are unlikely. In short, people may confuse the difficulty of imagining personal change with the unlikelihood of change itself.

Although the magnitude of this end of history illusion in some of our studies was greater for younger people than for older people, it was nonetheless evident at every stage of adult life that we could analyze. Both teenagers and grandparents seem to believe that the pace of personal change has slowed to a crawl and that they have recently become the people they will remain. History, it seems, is always ending today.

Surprise! Satisfied old folks live longer.

Contra a popular assumption that feisty, grumpy old farts are likely to live longer than sweet docile passive ones, Judith Graham reviews recent work by Becca Levy, an associate professor of epidemiology and psychology at Yale University that suggests the opposite - basically that older people become what they think, what their age stereotypes are. Some edited clips:

She looked at a a database of 660 adults age 50 and older in Oxford, Ohio, who were followed for a period of 23 years, from 1975 to 1998, and reported in The Journal of Personal and Social Psychology in 2002 that those with positive age stereotypes lived 7.5 years longer than those with negative stereotypes. She also did a series of laboratory experiments with older people, exposing them subliminally to negative or positive stereotypes by flashing words associated with aging on a computer screen too fast for them to process consciously. Then these seniors were asked to perform a task. Those exposed to negative words such as "decrepit" had poorer handwriting, slower walking speeds, higher levels of cardiovascular stress and a greater willingness to reject hypothetical medical interventions that could prolong their lives. Those primed with positive words such as "wisdom" did much better.

Levy established that people with positive age stereotypes were more likely to eat a balanced diet, exercise, limit their alcohol consumption, stop smoking and get regular physical exams, and that they had a higher level of physical functioning over time. Results were controlled for other factors like illness, gender, race and socioeconomic status…In these papers, Dr. Levy hypothesized that positive age stereotypes are associated with a greater sense of control and that this enhanced seniors' sense of self efficacy -- their ability to remain captains of their own ship, as it were.

Human evolution: endurance running made our brains larger and smarter.

Gretchen Reynolds reviews work suggesting that our advanced cleverness and big brains may have come not from the need to think but becoming endurance athletes, able to bring down swifter prey through sheer doggedness, jogging and plodding along behind them until the animals dropped. It turns out our larger brain size with respect to body size is also shown to some extent by species like dogs and rats that have a high innate endurance capacity, presumably evolved over millennia. it is also seen in mice and rats systematically bred to be marathon runners. After multiple generations, these animals begin to develop innately higher levels of tissue growth and health promoters, including the protein brain-derived neurotrophic factor, or BDNF. These substances are important for endurance performance. They also are known to drive brain growth. Such observations have led Raichlen and Polk to suggest that physical activity may have helped to make early humans smarter:

The hunting and gathering lifestyle adopted by human ancestors around 2 Ma required a large increase in aerobic activity. High levels of physical activity altered the shape of the human body, enabling access to new food resources (e.g. animal protein) in a changing environment. Recent experimental work provides strong evidence that both acute bouts of exercise and long-term exercise training increase the size of brain components and improve cognitive performance in humans and other taxa. However, to date, researchers have not explored the possibility that the increases in aerobic capacity and physical activity that occurred during human evolution directly influenced the human brain. Here, we hypothesize that proximate mechanisms linking physical activity and neurobiology in living species may help to explain changes in brain size and cognitive function during human evolution. We review evidence that selection acting on endurance increased baseline neurotrophin and growth factor signalling (compounds responsible for both brain growth and for metabolic regulation during exercise) in some mammals, which in turn led to increased overall brain growth and development. This hypothesis suggests that a significant portion of human neurobiology evolved due to selection acting on features unrelated to cognitive performance.

Why are older people more susceptible to fraud?

From Castle et al: a succinct set of observations. Their data is quite compelling.

Older adults are disproportionately vulnerable to fraud, and federal agencies have speculated that excessive trust explains their greater vulnerability. Two studies, one behavioral and one using neuroimaging methodology, identified age differences in trust and their neural underpinnings. Older and younger adults rated faces high in trust cues similarly, but older adults perceived faces with cues to untrustworthiness to be significantly more trustworthy and approachable than younger adults. This age-related pattern was mirrored in neural activation to cues of trustworthiness. Whereas younger adults showed greater anterior insula activation to untrustworthy versus trustworthy faces, older adults showed muted activation of the anterior insula to untrustworthy faces. The insula has been shown to support interoceptive awareness that forms the basis of “gut feelings,” which represent expected risk and predict risk-avoidant behavior. Thus, a diminished “gut” response to cues of untrustworthiness may partially underlie older adults’ vulnerability to fraud.

Body resonance and art appreciation.

Leder et al. have asked how hand movements reflected two styles of painting having similar content and historic period might interact with muscle movements in the viewer to influence their appreciation of the painting. Their introduction gives a bit of context for the work:

The question of how art creates aesthetic pleasure has puzzled researchers since the early days of psychology... In the visual arts, the common belief is that perceptual features, such as contrast or color, determine aesthetic pleasure; one mechanism underlying this perceptual path has been identified as processing efficiency... By contrast, since the late 19th century, the Empathists’ movement has claimed that a substantial source of aesthetic pleasure is empathy with the artwork... More precisely, Lee..argued that such empathy may result from episodes of sympathetic resonance of the perceiver’s own body with the artwork he or she is viewing. Currie...distinguished different kinds of resonance occurring through structures specifically responsible for motor processing, emotional responses, and even metaphorical word-action relations. Regarding motor simulations, Freedberg and Gallese..speculated that viewing artwork may activate neural movement programs associated with the way the artwork was produced ... Thus, one source of aesthetic empathy and thus aesthetic pleasure may stem from body resonances (of the perceiver’s body) with the movements that the artist made when producing the work.

They started with the view that perceiving a painting style elicits covert simulations of concordant hand movements in the viewer and that these stimulus-triggered simulations might be enhanced or interfered with by simultaneously performing hand movements that either resemble or do not resemble, respectively, the movements the artist made while creating the paintings... Making such movements might increase or decrease aesthetic appreciation, respectively, in the viewer...

Indeed, they found that when subjects were instructed to tap an eraser tip out of their view on the table top at their own pace (the motion used the stippling of pointillism), on viewing a series of pictures they preferred pointillist painting over stroke-style paintings. Instruction to move a pen out of view in strokes of about 20 cm from left to right on the table’s surface produced a preference for stroke-style paintings.

They showed that the movements were essential to the aesthetic episode of perceiving and evaluating the artwork by doing the control of have subjects perform matching or mismatching hand movements before viewing the artwork. This did not influence their art appreciation.

Lévi-Strauss - "shattered hologram" of aging.

I've been having a go at Jim Holt's popular book  "Why does the world exist? An existential detective story."  After three chapters of fascinating quotes from famous ancient and modern philosophers and scientists I skipped to the epilogue, and found a striking account given by the author of attending a small party at the Collège de France in celebration of the ninetieth birthday of Claude Lévi-Strauss. Lévi-Strauss was asked to give a little speech to the group, and begins with:

"Montaigne said that aging diminishes us each day in a way that, when death finally arrives, it takes away only a quarter or half the man. But Montaigne only lived to be fifty-nine, so he could have no idea of the extreme old age I find myself in today" - which, he adds, was one of the "most curious surprises of my existence."  He says he feels like a "shattered hologram" that has lost its unity but that still retains an image of the whole self. 

Lévi-Strauss goes on to talk about the "dialogue"  between the eroded self he has become - le moi réel - and the ideal self that coexists with it - le moi métronymique.  The latter, planning ambitious new intellectual projects, says to the former,  "You must continue."  But the former replies, "That's your business - only you can see things whole."  Levi-Strauss then thanks those of us assembled for helping him silence this futile dialogue and allowing his two selves of "coincide" again for a moment - "although," he adds,  "I am well aware that le moi réel will continue to sink toward its ultimate dissolution."

What an incredible description of what we experience as we continually loose our brain cells during aging: a receding shadow of the richness of the world once integrated by their antecedent and larger ensemble.

The final lines of Holt's epilogue, and the book:

Philosophy, n. A route of many roads leading from nowhere to nothing.

-AMBROSE BIERCE, The Devil's Dictionary

A usefull trick: Shifting attention to reduce emotional reactivity.

Thiruchselvam et al. do a simple demonstration of how our introspective attention can regulate our emotions after an unpleasant for fearful stimulus. Shifting the focus of that subsequent attention away from the challenging part of the image lessens emotional reactivity.  Here is their abstract, following by the basic experimental protocol:

Selective attention plays a fundamental role in emotion regulation. To date, research has examined individuals’ use of selective attention to regulate emotional responses during stimulus presentation. In the present study, we examined whether selective attention can be used to regulate emotional responses during a poststimulus period when representations are active within working memory (WM). On each trial, participants viewed either a negative or a neutral image. After the offset of the image, they maintained a representation of it in WM and were cued to focus their attention on either neutral or arousing aspects of that representation. Results showed that, relative to focusing on an arousing portion of a negative-image representation within WM, focusing on a neutral portion of the representation reduced both self-reported negative emotion and the late positive potential, a robust neural measure of emotional reactivity. These data suggest that selective attention can alter emotional responses arising from affective representations active within WM.

Figure (click to enlarge): Illustration of the trial structure. After an initial fixation period, an image (either negative or neutral) appeared on-screen for 1,500 ms. Then, two circles were overlaid on the image for 1,500 ms. For negative images (as shown here), one circle highlighted a neutral portion, whereas the other circle highlighted an arousing portion. For neutral images, both circles highlighted neutral portions. The image then disappeared, leaving a black screen for 750 ms, during which participants held the full image in working memory. Then, one of the circles was presented briefly for 250 ms. In the subsequent 3,000-ms interval, participants had to focus their attention on the portion of the image that had previously been contained within the target circle. Participants then rated how pleasant or unpleasant they felt.

Happy Holidays - a personal note - and MindBlog taking a break

My partner Len and I have traveled from our Fort Lauderdale snowbird retreat to Austin Texas to join  my ex-wife Marilyn Young, son Jonathan Bownds, daughter-in-law Shana Merlin, and my first grandchild, their new 9 month old grandson Sebastian.   They are now living in the Bownds family home that now has sheltered four generations of the Bownds family.  Daughter Sarah Bownds from Madison is also here.

Training parts of your brain for perceptual enhancement.

Geraint Rees and collaborators have done some fascinating work showing that training the spontaneous activity of just a part of our visual brain, corresponding to just a part of our visual field, can enhance the visual performance of that part of our vision:

Perception depends on the interplay of ongoing spontaneous activity and stimulus-evoked activity in sensory cortices. This raises the possibility that training ongoing spontaneous activity alone might be sufficient for enhancing perceptual sensitivity. To test this, we trained human participants to control ongoing spontaneous activity in circumscribed regions of retinotopic visual cortex using real-time functional MRI-based neurofeedback. After training, we tested participants using a new and previously untrained visual detection task that was presented at the visual field location corresponding to the trained region of visual cortex. Perceptual sensitivity was significantly enhanced only when participants who had previously learned control over ongoing activity were now exercising control and only for that region of visual cortex. Our new approach allows us to non-invasively and non-pharmacologically manipulate regionally specific brain activity and thus provide “brain training” to deliver particular perceptual enhancements.

For guys who want to attract women?

Perhaps there is a human equivalent of the non-volatile protein pheromone darcin, that Roberts et al. show to stimulate spatial preference and learning in mice. Female mice preferred locations where male urine (or synthesized darcin) had been found, and remembered these spatial locations for 2 weeks post-exposure. (Scent marking is an essential component of communication for most mammals. Individuals remember the location of scent marks and regularly revisit marked sites, presumably to assess the condition and status of the animal doing the marking. It is known that individuals can follow odor or pheromone gradients to locate another individual, but relocating scent marks is a much more difficult task given the small amount of volatile compounds deposited, and their static nature.) Here is the abstract:

Many mammals use scent marking for sexual and competitive advertisement, but little is known about the mechanism by which scents are used to locate mates and competitors. We show that darcin, an involatile protein sex pheromone in male mouse urine, can rapidly condition preference for its remembered location among females and competitor males so that animals prefer to spend time in the site even when scent is absent. Learned spatial preference is conditioned through contact with darcin in a single trial and remembered for approximately 14 days. This pheromone-induced learning allows animals to relocate sites of particular social relevance and provides proof that pheromones such as darcin can be highly potent stimuli for social learning.

Unconscious reading and arithmetic.

Here is a fascinating bit from Sklar et al.:

The modal view in the cognitive and neural sciences holds that consciousness is necessary for abstract, symbolic, and rule-following computations. Hence, semantic processing of multiple-word expressions, and performing of abstract mathematical computations, are widely believed to require consciousness. We report a series of experiments in which we show that multiple-word verbal expressions can be processed outside conscious awareness and that multistep, effortful arithmetic equations can be solved unconsciously. All experiments used Continuous Flash Suppression to render stimuli invisible for relatively long durations (up to 2,000 ms). Where appropriate, unawareness was verified using both objective and subjective measures. The results show that novel word combinations, in the form of expressions that contain semantic violations, become conscious before expressions that do not contain semantic violations, that the more negative a verbal expression is, the more quickly it becomes conscious, and that subliminal arithmetic equations prime their results. These findings call for a significant update of our view of conscious and unconscious processes.

(note:  Continuous Flash Suppression consists of a presentation of a target stimulus to one eye and a simultaneous presentation of rapidly changing masks to the other eye. The rapidly changing masks dominate awareness until the target breaks into consciousness. This suppression may last seconds. To examine arithmetic, another symbolic, rule-following system, the authors moved from a breaking-into-consciousness design to a priming design. They examined the effects of subliminal stimuli on conscious stimuli that follow them, using both subjective and objective measures to verify the subliminality of the primes.)

Grin and bear it.

Kraft and Pressman make a nice observation on linking muscle movement to emotion, showing how manipulating the muscles involved in a smile can alter the stress response:

In the study reported here, we investigated whether covertly manipulating positive facial expressions would influence cardiovascular and affective responses to stress. Participants (N = 170) naive to the purpose of the study completed two different stressful tasks while holding chopsticks in their mouths in a manner that produced a Duchenne smile, a standard smile, or a neutral expression. Awareness was manipulated by explicitly asking half of all participants in the smiling groups to smile (and giving the other half no instructions related to smiling). Findings revealed that all smiling participants, regardless of whether they were aware of smiling, had lower heart rates during stress recovery than the neutral group did, with a slight advantage for those with Duchenne smiles. Participants in the smiling groups who were not explicitly asked to smile reported less of a decrease in positive affect during a stressful task than did the neutral group. These findings show that there are both physiological and psychological benefits from maintaining positive facial expressions during stress.

Brain plasticity induced by musical training.

As a lifelong pianist, I have always regarded with awe pianists like Horowitz and Rubenstein who have continued to perform into into their advanced old age. I have done some 4 hands recitals here in my winter nest of Fort Lauderdale with an 87-year old retired music professor and performer who still gives solo concerts. Musical performance makes very complex demands on visual, auditory, and motor processing. Numerous studies have shown that subcortical and cortical brain regions can change with musical training. Hernholz and Zatorre offer a massive review of musical training as a framework for brain plasticity in a recent issue of Neuron. I can't even begin to summarize the abundant material presented and offer only the abstract and one sample figure here (motivated readers can request a PDF of the article from me.)

Musical training has emerged as a useful framework for the investigation of training-related plasticity in the human brain. Learning to play an instrument is a highly complex task that involves the interaction of several modalities and higher-order cognitive functions and that results in behavioral, structural, and functional changes on time scales ranging from days to years. While early work focused on comparison of musical experts and novices, more recently an increasing number of controlled training studies provide clear experimental evidence for training effects. Here, we review research investigating brain plasticity induced by musical training, highlight common patterns and possible underlying mechanisms of such plasticity, and integrate these studies with findings and models for mechanisms of plasticity in other domains.

Figure 2 (click to enlarge). Interindividual Differences in Auditory Cortical Structure and Function(A) Variability in auditory cortex gray matter concentration and cortical thickness predicted performance on a melodic transposition task (adapted from Foster and Zatorre, 2010).(B) Different rates of behavioral improvement during pitch memory training were accompanied by differential training-related functional changes in secondary auditory areas (adapted from Gaab et al., 2006).(C) BOLD signal covariation to increasing pitch size in microtonal melodies prior to training in both left and right auditory cortices was predictive of the speed with which learning occurred, such that those individuals who subsequently learned more quickly had an initially steeper response function (adapted from Zatorre et al., in press).

The herding hormone

Yet another addition, from Stallen et al., to the long list of studies on oxytocin and our social behaviors (enter oxytocin in the search box in the left column to pull up the numerous mindblog posts on oxytocin effects on our behaviors):

People often conform to others with whom they associate. Surprisingly, however, little is known about the possible hormonal mechanisms that may underlie in-group conformity. Here, we examined whether conformity toward one’s in-group is altered by oxytocin, a neuropeptide often implicated in social behavior. After administration of either oxytocin or a placebo, participants were asked to provide attractiveness ratings of unfamiliar visual stimuli. While viewing each stimulus, participants were shown ratings of that stimulus provided by both in-group and out-group members. Results demonstrated that on trials in which the ratings of the in-group and out-group were incongruent, the ratings of participants given oxytocin conformed to the ratings of their in-group but not of their out-group. Participants given a placebo did not show this in-group bias. These findings indicate that administration of oxytocin can influence subjective preferences, and they support the view that oxytocin’s effects on social behavior are context dependent.

Brain imaging of the positive bias we place on social feedback.

Continuing the social brain thread started by yesterday's post, I pass on this piece by Korn et al. showing brain correlates of the rose colored glasses we put on interpreting social feedback from others. Participants in the study rated how much 40 positive and 40 negative trait adjectives applied to themselves and to one other person before and after receiving feedback ratings of themselves. The critical test for positively biased updating was finding that the changes toward desirable feedback were larger than the changes toward undesirable feedback. Here is their abstract:

Receiving social feedback such as praise or blame for one's character traits is a key component of everyday human interactions. It has been proposed that humans are positively biased when integrating social feedback into their self-concept. However, a mechanistic description of how humans process self-relevant feedback is lacking. Here, participants received feedback from peers after a real-life interaction. Participants processed feedback in a positively biased way, i.e., they changed their self-evaluations more toward desirable than toward undesirable feedback. Using functional magnetic resonance imaging we investigated two feedback components. First, the reward-related component correlated with activity in ventral striatum and in anterior cingulate cortex/medial prefrontal cortex (ACC/MPFC). Second, the comparison-related component correlated with activity in the mentalizing network, including the MPFC, the temporoparietal junction, the superior temporal sulcus, the temporal pole, and the inferior frontal gyrus. This comparison-related activity within the mentalizing system has a parsimonious interpretation, i.e., activity correlated with the differences between participants' own evaluation and feedback. Importantly, activity within the MPFC that integrated reward-related and comparison-related components predicted the self-related positive updating bias across participants offering a mechanistic account of positively biased feedback processing. Thus, theories on both reward and mentalizing are important for a better understanding of how social information is integrated into the human self-concept.

Enhancing social ability with brain stimulation.

Social information is thought to be processed by a specific set of neural circuits often referred to as the ‘social brain’ The figure shows localization in human brains of the relevant temporo-parietal junction orbitofrontal cortex in lateral (top) and medial (bottom) views.  Santiesteban et al. now show that low levels of direct current stimulation of the temporoparietal junction region improves control of self-other representations. (The electrical stimulation is two saline-soaked surface sponge electrodes driven by a battery driven constant low current stimulator). Here is their summary, followed by the abstract:

-OFC neurons respond to social visual stimul
-OFC neurons differentiate between socially defined classes of images
-OFC neurons signal the value of social information for making decisions
-More OFC neurons convey social information than fluid reward magnitude.

Primate evolution produced an increased capacity to respond flexibly to varying social contexts as well as expansion of the prefrontal cortex [1,2]. Despite this association, how prefrontal neurons respond to social information remains virtually unknown. People with damage to their orbitofrontal cortex (OFC) struggle to recognize facial expressions [3,4], make poor social judgments [5,6], and frequently make social faux pas [7,8]. Here we test explicitly whether neurons in primate OFC signal social information and, if so, how such signals compare with responses to primary fluid rewards. We find that OFC neurons distinguish images that belong to socially defined categories, such as female perinea and faces, as well as the social dominance of those faces. These modulations signaled both how much monkeys valued these pictures and their interest in continuing to view them. Far more neurons signaled social category than signaled fluid value, despite the stronger impact of fluid reward on monkeys’ choices. These findings indicate that OFC represents both the motivational value and attentional priority of other individuals, thus contributing to both the acquisition of information about others and subsequent social decisions. Our results betray a fundamental disconnect between preferences expressed through overt choice, which were primarily driven by the desire for more fluid, and preferential neuronal processing, which favored social computations.