Observing brain correlates of social interactions.

Bilek et al. look at coordinated brain activity during social interactions between two people in a joint attention paradigm, using a hyperscanning procedure in which neuroimaging is done with the subjects' brain activity measured in two scanner sites coupled over the internet. Allowing two humans to see (and possibly hear) each other in a hyperscanning framework makes possible an immersive social interaction while both participant’s brains are imaged. The authors constructed a setup with delay-free data transmission and precisely synchronized data acquisition, in addition to a live video stream provided between scanner sites during the sessions. From their significance and abstract sections:

Social interaction is the likely driver of human brain evolution, critical for health, and underlies phenomena as varied as childhood development, stock market behavior, and much of what is studied in the humanities. However, appropriate experimental methods to study the underlying brain processes are still developing and technically challenging...Here, we used hyperscanning functional MRI (fMRI) to study information flow between brains of human dyads during real-time social interaction in a joint attention paradigm. In a hardware setup enabling immersive audiovisual interaction of subjects in linked fMRI scanners, we characterize cross-brain connectivity components that are unique to interacting individuals, identifying information flow between the sender’s and receiver’s temporoparietal junction. We replicate these findings in an independent sample and validate our methods by demonstrating that cross-brain connectivity relates to a key real-world measure of social behavior. Together, our findings support a central role of human-specific cortical areas in the brain dynamics of dyadic interactions and provide an approach for the noninvasive examination of the neural basis of healthy and disturbed human social behavior with minimal a priori assumptions.

Figure: Neural coupling of sender and receiver right temporoparietal junctions in a shared attention paradigm. A, Discovery study performed on 26 subjects (13 pairs); B, Replication study performed on 50 subjects (25 pairs).

Early environment and stress systems in children.

Most of the detailed work on the long term effects of adverse early life environment on stress response systems has been done with rodent models. McLaughlin et al. now present results from the Bucharest Early Intervention Project examining whether randomized placement of children into a family caregiving environment alters development of the autonomic nervous system and HPA axis in children exposed to early-life deprivation associated with institutional rearing. They provide the first experimental evidence in humans for a sensitive period with regard to stress response system development.

Disruptions in stress response system functioning are thought to be a central mechanism by which exposure to adverse early-life environments influences human development. Although early-life adversity results in hyperreactivity of the sympathetic nervous system (SNS) and hypothalamic–pituitary–adrenal (HPA) axis in rodents, evidence from human studies is inconsistent. We present results from the Bucharest Early Intervention Project examining whether randomized placement into a family caregiving environment alters development of the autonomic nervous system and HPA axis in children exposed to early-life deprivation associated with institutional rearing. Electrocardiogram, impedance cardiograph, and neuroendocrine data were collected during laboratory-based challenge tasks from children (mean age = 12.9 y) raised in deprived institutional settings in Romania randomized to a high-quality foster care intervention (n = 48) or to remain in care as usual (n = 43) and a sample of typically developing Romanian children (n = 47). Children who remained in institutional care exhibited significantly blunted SNS and HPA axis responses to psychosocial stress compared with children randomized to foster care, whose stress responses approximated those of typically developing children. Intervention effects were evident for cortisol and parasympathetic nervous system reactivity only among children placed in foster care before age 24 and 18 months, respectively, providing experimental evidence of a sensitive period in humans during which the environment is particularly likely to alter stress response system development. We provide evidence for a causal link between the early caregiving environment and stress response system reactivity in humans with effects that differ markedly from those observed in rodent models.

Cognitive training enhances intrinsic brain connectivity in childhood.

A fascinating open access article from Astle et al., who found changes in brain connectivity in 8-11 year old children who completed 20 sessions of computerized working memory training at home:

In human participants, the intensive practice of particular cognitive activities can induce sustained improvements in cognitive performance, which in some cases transfer to benefits on untrained activities. Despite the growing body of research examining the behavioral effects of cognitive training in children, no studies have explored directly the neural basis of these training effects in a systematic, controlled fashion. Therefore, the impact of training on brain neurophysiology in childhood, and the mechanisms by which benefits may be achieved, are unknown. Here, we apply new methods to examine dynamic neurophysiological connectivity in the context of a randomized trial of adaptive working memory training undertaken in children. After training, connectivity between frontoparietal networks and both lateral occipital complex and inferior temporal cortex was altered. Furthermore, improvements in working memory after training were associated with increased strength of neural connectivity at rest, with the magnitude of these specific neurophysiological changes being mirrored by individual gains in untrained working memory performance.

Ideology distorts perception of social mobility in the U.S.

I find it interesting that I share the same misperception of social mobility changes that are noted in this piece of work by Chambers et al.:

The ability to move upward in social class or economic position (i.e., social mobility) is a defining feature of the American Dream, yet recent public-opinion polls indicate that many Americans are losing confidence in the essential fairness of the system and their opportunities for financial advancement. In two studies, we examined Americans’ perceptions of both current levels of mobility in the United States and temporal trends in mobility, and we compared these perceptions with objective indicators to determine perceptual accuracy. Overall, participants underestimated current mobility and erroneously concluded that mobility has declined over the past four decades. These misperceptions were more pronounced among politically liberal participants than among politically moderate or conservative ones. These perception differences were accounted for by liberals’ relative dissatisfaction with the current social system, social hierarchies, and economic inequality. These findings have important implications for theories of political ideology.

The author's introduction, after noting pessimistic views on social mobility - "A recent Gallup poll (Dugan & Newport, 2013) found that only 52% of Americans agreed that there is plenty of opportunity for the average person to get ahead in life—down from 81% a mere 15 years earlier and the lowest level in over six decades." - points to the actual data on social mobility changes:

The publication of a recent, multidecade report provided us with an opportunity to compare those public perceptions with economic reality. Chetty, Hendren, Kline, Saez, and Turner (2014a, 2014b) compared the tax records of nearly 40 million American adults with those of their parents 20 years earlier, assessing changes in individuals’ economic position relative to their starting point in life (i.e., their parents’ economic position). They also compared individuals born in different decades, from the early 1970s through the mid 1990s, to assess any generational changes in mobility patterns. First, they found (as have Hertz, 2007; Lee & Solon, 2009) that intergenerational mobility rates have not declined, but in fact remained stable during the three-decade period they examined—contrary to popular belief (Dugan & Newport, 2013; Pew Research Center, 2012). Second, their data revealed that Americans enjoy—depending on one’s perspective—a substantial amount of social mobility. For example, of individuals born to parents in the bottom third of the income distribution (i.e., lower-class parents), 49% remained in the bottom third later in life, whereas 51% moved up to the middle or top third. In other words, despite their disadvantaged backgrounds, half of them were upwardly mobile (though still below the two-thirds one might expect based on the American Dream). Moreover, because they utilized much larger sample sizes, actual tax records (instead of self-reported income), and multiple indicators of mobility (e.g., incomes, college attendance rates), Chetty and colleagues’ study yields more precise estimates of social mobility than prior studies, and their findings are consistent with those of other published reports (Pew Research Center, 2013; U.S. Department of the Treasury, 2007). This makes their study the most appropriate standard to gauge our participants’ perceptual accuracy.

Economic origins of ultrasociality

Gowdy and Krall, in a manuscript under review by Behavioral and Brain Sciences, argue that the transition to agriculture in ants, termites, and our humans species generated the need for the extreme role specializations and ultrasociality that distinguish us from social species that depend on foraging for food. (Interested readers can obtain a copy of the MS from me).  I pass on a clip from the introduction, followed by their abstract.

With the widespread adoption of agriculture some 10,000 years ago human societies took on some important characteristics shared with social insects—ants and termites in particular—that also engage in the production of their own food. These characteristics represented a sharp break in the evolutionary history of these lineages and led to two important outcomes (1) ecosystem domination as a product of a dramatic increase in population size and much more intensive resource exploitation and (2) the suppression of individual autonomy as the group itself became the focus of economic organization. The evolution of agriculture in fungus-growing ants and termites, and in human societies, is an example of convergent evolution—the independent evolution of similar characteristics in species not closely related. In terms of genetics, ants, humans and termites could hardly be more different. Yet in all three lineages similar patterns of economic organization emerge through similar selection pressures. We use the term ultrasociality to refer to these lineages and we address the question of its origin through the fundamental question of evolutionary biology: “where did something come from and what were the selection pressures that favored its spread?”

Abstract:

Ultrasociality refers to the social organization of a few species, including humans and some social insects, having complex division of labor, city states and an almost exclusive dependence on agriculture for subsistence. We argue that the driving forces in the evolution of these ultrasocial societies were economic. With the agricultural transition, species could directly produce their own food and this was such a competitive advantage that those species now dominate the planet. Once underway, this transition was propelled by the selection of withinspecies groups that could best capture the advantages of (1) actively managing the inputs to food production, (2) a more complex division of labor, and (3) increasing returns to larger scale and larger group size. Together these factors reoriented productive life and radically altered the structure of these societies. Once agriculture began, populations expanded as these economic drivers opened up new opportunities for the exploitation of resources and the active management of inputs to food production. With intensified group-level competition, larger populations and intensive resource exploitation became competitive advantages and the “social conquest of earth” was underway. Ultrasocial species came to dominate the earth’s ecosystems. Ultrasociality also brought a loss of autonomy for individuals within the group. We argue that exploring the common causes and consequences of ultrasociality in humans and the social insects that adopted agriculture can provide fruitful insights into the evolution of complex human society.

Explaining the increase in individualism in the U.S. over the past 150 years.

Grossman and Varnum quantify shifts in eight cultural-level correlates of individualism reflected in the domains of cultural products (individualist and collectivist themes in books, behavioral patterns of uniqueness such as baby-naming practices, behavioral and demographic correlates of individualism-collectivism reflecting the strength of family ties such as family size, percentage of single-person households and multigenerational households, divorce rates, etc.) and test the relationship between these indicators and trends in pathogen prevalence, the number of disasters, urbanization, secularism, and socioeconomic structure. Their data suggest socioeconomic structure shifts have been the most potent predictor of changes across a wide range of individualism-related markers. Compared with blue-collar occupations, white-collar occupations afford and demand more autonomy and self-direction, and greater affluence enables individuals to pursue their own interests without consulting or depending on larger collectives. Their abstract:

Why do cultures change? The present work examined cultural change in eight cultural-level markers, or correlates, of individualism in the United States, all of which increased over the course of the 20th century: frequency of individualist themes in books, preference for uniqueness in baby naming, frequency of single-child relative to multichild families, frequency of single-generation relative to multigeneration households, percentage of adults and percentage of older adults living alone, small family size, and divorce rates (relative to marriage rates). We tested five key hypotheses regarding cultural change in individualism-collectivism. As predicted by previous theories, changes in socioeconomic structure, pathogen prevalence, and secularism accompanied changes in individualism averaged across all measures. The relationship with changes in individualism was less robust for urbanization. Contrary to previous theories, changes in individualism were positively (as opposed to negatively) related to the frequency of disasters. Time-lagged analyses suggested that only socioeconomic structure had a robust effect on individualism; changes in socioeconomic structure preceded changes in individualism. Implications for anthropology, psychology, and sociology are discussed.

The most clever crow yet....

MindBlog has done posts on a raven making a tool, an urban crow with street smarts, and now I pass on a video that a friend alerted me to, showing a crow solving a multi-step problem.

Effortless awareness: Linking subjective experience with brain activity during focused meditation with real-time fMRI

Garrison and collaborators, whose work I have referenced in a previous post and also at the end of my "Upstairs/Downstairs" web lecture, give a further account of their work in this abstract from their open source article in Frontiers in Human Neuroscience:

Neurophenomenological studies seek to utilize first-person self-report to elucidate cognitive processes related to physiological data. Grounded theory offers an approach to the qualitative analysis of self-report, whereby theoretical constructs are derived from empirical data. Here we used grounded theory methodology (GTM) to assess how the first-person experience of meditation relates to neural activity in a core region of the default mode network—the posterior cingulate cortex (PCC). We analyzed first-person data consisting of meditators' accounts of their subjective experience during runs of a real time fMRI neurofeedback study of meditation, and third-person data consisting of corresponding feedback graphs of PCC activity during the same runs. We found that for meditators, the subjective experiences of “undistracted awareness” such as “concentration” and “observing sensory experience,” and “effortless doing” such as “observing sensory experience,” “not efforting,” and “contentment,” correspond with PCC deactivation. Further, the subjective experiences of “distracted awareness” such as “distraction” and “interpreting,” and “controlling” such as “efforting” and “discontentment,” correspond with PCC activation. Moreover, we derived several novel hypotheses about how specific qualities of cognitive processes during meditation relate to PCC activity, such as the difference between meditation and “trying to meditate.” These findings offer novel insights into the relationship between meditation and mind wandering or self-related thinking and neural activity in the default mode network, driven by first-person reports.

Improving vision in older adults.

I'm now a Fort Lauderdale, Florida resident (except for 5 months of spring and summer in Madison WI.), and have several friends 85 and older still still driving on the death defying I-95 interstate that links Palm Beach, Fort Lauderdale, and Miami, even though their visual capabilities have clearly declined. This is an age cohort that is increasing by 350% between 2000 and 2050. One of the most obvious declines in their visual processing is with contrast sensitivity, resolving small changes in illumination and shape detail, especially at high spatial frequencies. DeLoss et al., in a study in the same vein as others reported in this blog (enter aging in the search box in the left column), show that doing simple discrimination exercises for 1.5 hr per day of testing and training over 7 days resulted in performance that was not statistically different from that of younger college age adults prior to training. (These were exercises of the sort currently available online (See Brainhq.com or Luminosity.com). Here is the abstract, followed by figures illustrating the test employed.

A major problem for the rapidly growing population of older adults (age 65 and over) is age-related declines in vision, which have been associated with increased risk of falls and vehicle crashes. Research suggests that this increased risk is associated with declines in contrast sensitivity and visual acuity. We examined whether a perceptual-learning task could be used to improve age-related declines in contrast sensitivity. Older and younger adults were trained over 7 days using a forced-choice orientation-discrimination task with stimuli that varied in contrast with multiple levels of additive noise. Older adults performed as well after training as did college-age younger adults prior to training. Improvements transferred to performance for an untrained stimulus orientation and were not associated with changes in retinal illuminance. Improvements in far acuity in younger adults and in near acuity in older adults were also found. These findings indicate that behavioral interventions can greatly improve visual performance for older adults.

Example of the task used in the study. In each trial, subjects saw a Gabor patch at one of two standard orientations—25° clockwise (shown here) or 25° counterclockwise for training and testing trials, 45° clockwise or 45° counterclockwise for familiarization trials. After this Gabor patch disappeared, subjects saw a second stimulus and had to judge whether it was rotated clockwise or counterclockwise in comparison with the standard orientation (the examples shown here are rotated 15° clockwise and counterclockwise off the standard orientation, respectively). 

Example of contrast and noise levels used in the experiment. Gabor patches are displayed at 75% contrast in the top row and at 25% contrast in the bottom row. Stimuli were presented in five blocks (examples shown from left to right). There was no noise in the first block, but starting with the second block, stimuli were presented in Gaussian noise, with the noise level increasing in each subsequent block.

A clip from the NY Times review:

...the subjects watched 750 striped images that were rapidly presented on a computer screen with subtle changes in the visual “noise” surrounding them — like snow on a television. The viewer indicated whether the images were rotating clockwise or counterclockwise. The subject would hear a beep for every correct response.

Each session took an hour and a half. The exercises were taxing, although the subjects took frequent breaks. But after five sessions, the subjects had learned to home in more precisely on the images and to filter out the distracting visual noise. After the training, the older adults performed as well as those 40 years younger, before their own training.

Emotion is a component of the earliest stages of perception.

Emotions and perceptions are generally assumed to be separate and parallel realms of the mind. Topolinski et al. show to the contrary that affect is a genuine online-component of perception, instantaneously mirroring the success of different perceptual stages. Here is their abstract, following by a graphic of the impossible Necker cube used in experiments 4 and 5.

Current theories assume that perception and affect are separate realms of the mind. In contrast, we argue that affect is a genuine online-component of perception instantaneously mirroring the success of different perceptual stages. Consequently, we predicted that the success (or failure) of even very early and cognitively encapsulated basic visual processing steps would trigger immediate positive (or negative) affective responses. To test this assumption, simple visual stimuli that either allowed or obstructed early visual processing stages without participants being aware of this were presented briefly. Across 5 experiments, we found more positive affective responses to stimuli that allowed rather than obstructed Gestalt completion at certain early visual stages (Experiments 1–3; briefest presentation 100 ms with post-mask), and visual disambiguation in possible vs. impossible Necker cubes (Experiments 4 and 5; briefest presentation 100 ms with post-mask). This effect was observed both on verbal preference ratings (Experiments 1, 2, and 4) and as facial muscle responses occurring within 2–4 s after stimulus onset (zygomaticus activity; Experiments 3 and 7). For instance, in participants unaware of spatial possibility we found affective discrimination between possible and impossible Necker cubes (the famous Freemish Crate) for 100 ms presentation timings, although a conscious discrimination took more than 2000 ms (Experiment 4).

The Freemish Crate (impossible Necker Cube) which features inconsistent mutual occlusions of some of the lines constituting the cube and thus represents a cube that cannot exist in three dimensions. Such an impossible cube renders visual disambiguation impossible. (a), the visual manipulation from Experiments 4 and 5 (b), examples of a possible (c), and an impossible Necker cube (d).

Subliminal learning can nudge future control decisions.

A dichotomy is proposed by most dual-system approaches to cognition (as, for example, in Kahneman's 2011 book "Thinking, fast and slow") in which processes are nonconscious, fast, associative, automatic, rigid, and subjectively effortless, or they are conscious, slow, propositional, controlled, flexible, and effortful. Farooqui and Manly demonstrate a more nuanced reality: unconscious associative learning of subliminal relations. They describe the setup:

In our experiments, participants performed task-switching tests. On each trial, participants saw a colored rectangle that indicated which of two tasks should be performed on the numbers or letter inside it. A couple of seconds before these were presented, one of three subliminal cues appeared: One cue predicted a switch from the prior task, another cue predicted a repetition of the prior task, and a third cue was nonpredictive (and could therefore appear before either type of trial). The cues were not linked to any task set; rather, they predicted the switch/repeat status of the trial, and therefore the participants could use them to make proactive goal-directed changes in the currently active cognitive set.

They found that

Despite participants’ being entirely unaware of subliminal cues in a series of challenging switch tasks, cues predicting switch trials were reliably associated with improved performance. This robust effect was observed across four variants of stimuli and tasks in four independent participant groups.

From their summary abstract:

... This utilization of subliminal information was flexible and adapted to a change in cues predicting task switches and occurred only when switch trials were difficult and effortful. When cues were consciously visible, participants were unable to discern their relevance and could not use them to enhance switch performance. Our results show that unconscious cognition can implicitly use subliminal information in a goal-directed manner for anticipatory control, and they also suggest that subliminal representations may be more conducive to certain forms of associative learning.

Mind wandering and mental autonomy.

I'm on my third reading of a dense open access paper by Thomas Metzinger in Frontiers in Psychology titled "The myth of cognitive agency: subpersonal thinking as a cyclically recurring loss of mental autonomy." Readers interested in my Upstairs/Downstairs web lecture or the March 19 post on Metzinger might want to check it out. My headache sets in from trying to remember and keep in mind the numerous abbreviations he uses for economy in the text - AA, CA, PSM,EAM, SRB, UI, etc. - a whole glossary for them is provided. Of particular interest are his two suggested criteria, noted in the abstract just below, for "individuating single episodes of mind-wandering, namely, the “self-representational blink” (SRB) and a sudden shift in the phenomenological “unit of identification” (UI)." I pass on the abstract first, and then a few clips from the sections of the paper titled "Mind wandering as a switch in the unit of identification" and "The re-appearance of meta-awareness"

This metatheoretical paper investigates mind wandering from the perspective of philosophy of mind. It has two central claims. The first is that, on a conceptual level, mind wandering can be fruitfully described as a specific form of mental autonomy loss. The second is that, given empirical constraints, most of what we call “conscious thought” is better analyzed as a subpersonal process that more often than not lacks crucial properties traditionally taken to be the hallmark of personal-level cognition - such as mental agency, explicit, consciously experienced goal-directedness, or availability for veto control. I claim that for roughly two thirds of our conscious life-time we do not possess mental autonomy (M-autonomy) in this sense. Empirical data from research on mind wandering and nocturnal dreaming clearly show that phenomenally represented cognitive processing is mostly an automatic, non-agentive process and that personal-level cognition is an exception rather than the rule. This raises an interesting new version of the mind-body problem: How is subpersonal cognition causally related to personal-level thought? More fine-grained phenomenological descriptions for what we called “conscious thought” in the past are needed, as well as a functional decomposition of umbrella terms like “mind wandering” into different target phenomena and a better understanding of the frequent dynamic transitions between spontaneous, task-unrelated thought and meta-awareness. In an attempt to lay some very first conceptual foundations for the now burgeoning field of research on mind wandering, the third section proposes two new criteria for individuating single episodes of mind-wandering, namely, the “self-representational blink” (SRB) and a sudden shift in the phenomenological “unit of identification” (UI). I close by specifying a list of potentially innovative research goals that could serve to establish a stronger connection between mind wandering research and philosophy of mind.

And, from the text:

Mind Wandering as a Switch in the Unit of Identification

Let us look at a second phenomenological feature of mind wandering that could, if correctly described, yield a new theoretical perspective. Perhaps the most interesting phenomenological feature of mind wandering is a sudden shift in the UI (phenomenal unit of identification). The UI is the phenomenal property with which we currently identify, exactly the form of currently active conscious content that generates the subjective experience of “I am this!” Please note how many mind wandering episodes are phenomenologically disembodied states, because perceptual decoupling often also means decoupling from current body perception...

The Re-Appearance of Meta-Awareness

How exactly does an episode of mind wandering end? Schooler and colleagues, referring to work by the late Daniel Wegner, point out that regaining meta-awareness may be accompanied by an illusion of control...“I have just regained meta-awareness, because I just introspectively realized that I was lost in mind wandering!”

Because mindfulness and mind wandering are opposing constructs, the process of losing and regaining meta-awareness can be most closely studied in different stages of classical mindfulness meditation. In the early stages of object-oriented meditation, there will typically be cyclically recurring losses of mental autonomy, plus an equally recurring mental action, namely the decision to gently, but firmly bring the focus of attention back to the formal object of meditation, for example to interoceptive sensations associated with the respiratory process. Here, the phenomenology will often be one of mental agency, goal directedness, and a mild sense of effort. In advanced stages of open monitoring meditation, however, the aperture of attention has gradually widened, typically resulting in an effortless and choiceless awareness of the present moment as a whole. Such forms of stable meta-awareness may now be described as shifts to as state without a UI. Whereas in beginning stages of object-oriented mindfulness practice, the meditator identifies with an internal model of a mental agent directed at a certain goal-state (“the meditative self”), meta-awareness of the second kind is typically described as having an effortless and non-agentive quality. Interestingly, the neural correlates pertaining to this difference between “trying to meditate” and meditation are now beginning to emerge (Garrison et al., 2013, graphic from this paper is in my Upstairs/Downstairs web lecture).

The evolution of gender effects on empathy.

Christov-Moore et al. offer a review making the point that differences in the capacity for empathy between males and females have deep evolutionary and developmental roots, in addition to any cultural expectations about gender roles. The review references a graphic summary of brain areas involved in experience sharing which I also pass on.

 Highlights

• Sex differences in empathy have phylogenetic and ontogenetic roots in biology. 

• As primary caregivers females evolved adaptations to be sensitive to infants’ signals. 

• Sex differences in empathy appear to be consistent and stable across the lifespan. 

• In affective empathy, females, compared to men, show higher emotional responsivity. 

• Males show greater recruitment of brain areas for the control of cognitive empathy.

Abstract

Evidence suggests that there are differences in the capacity for empathy between males and females. However, how deep do these differences go? Stereotypically, females are portrayed as more nurturing and empathetic, while males are portrayed as less emotional and more cognitive. Some authors suggest that observed gender differences might be largely due to cultural expectations about gender roles. However, empathy has both evolutionary and developmental precursors, and can be studied using implicit measures, aspects that can help elucidate the respective roles of culture and biology. This article reviews evidence from ethology, social psychology, economics, and neuroscience to show that there are fundamental differences in implicit measures of empathy, with parallels in development and evolution. Studies in nonhuman animals and younger human populations (infants/children) offer converging evidence that sex differences in empathy have phylogenetic and ontogenetic roots in biology and are not merely cultural byproducts driven by socialization. We review how these differences may have arisen in response to males’ and females’ different roles throughout evolution. Examinations of the neurobiological underpinnings of empathy reveal important quantitative gender differences in the basic networks involved in affective and cognitive forms of empathy, as well as a qualitative divergence between the sexes in how emotional information is integrated to support decision making processes. Finally, the study of gender differences in empathy can be improved by designing studies with greater statistical power and considering variables implicit in gender (e.g., sexual preference, prenatal hormone exposure). These improvements may also help uncover the nature of neurodevelopmental and psychiatric disorders in which one sex is more vulnerable to compromised social competence associated with impaired empathy.

The summary graphic by Zaki and Ochsner :

Neuroscientific approaches to studying experience sharing and mentalizing. (a) The experimental logic underlying first-person perception studies of experience sharing. The blue circle represents brain regions engaged by direct, first-person experience of an affective response, motor intention, or other internal state. The yellow circle represents regions engaged by third-person observation of someone else experiencing the same kind of internal state. To the extent that a region demonstrates neural resonance—common engagement by first- and third-person experience (green overlap)—it is described as supporting a perceiver's vicarious experience of a target's state (regions demonstrating such properties are highlighted in green in c). (b) Studies of mentalizing typically ask participants to make judgments about targets’ beliefs, thoughts, intentions and/or feelings, as depicted in highly stylized social cues, including vignettes (top left), posed facial expressions (right), or even more isolated nonverbal cues, such as target eye gaze (bottom left). Regions engaged by such tasks (blue in c) are described as contributing to perceivers’ ability to mentalize. (c) Brain regions associated with experience sharing (green) and mentalizing (blue). IPL, inferior parietal lobule; TPJ, temporoparietal junction; pSTS, posterior superior temporal sulcus; TP, temporal pole; AI, anterior insula; PMC, premotor cortex; PCC, posterior cingulate cortex; ACC, anterior cingulate cortex; MPFC, medial prefrontal cortex.

Observing leadership emergence through interpersonal brain synchronization.

Interesting work from Jiang et al., who show that show that interpersonal neural synchronization is significantly higher between leaders and followers than between followers and followers, suggesting that leaders emerge by synchronizing their brain activity with that of the followers:

The neural mechanism of leader emergence is not well understood. This study investigated (i) whether interpersonal neural synchronization (INS) plays an important role in leader emergence, and (ii) whether INS and leader emergence are associated with the frequency or the quality of communications. Eleven three-member groups were asked to perform a leaderless group discussion (LGD) task, and their brain activities were recorded via functional near infrared spectroscopy (fNIRS)-based hyperscanning. Video recordings of the discussions were coded for leadership and communication. Results showed that the INS for the leader–follower (LF) pairs was higher than that for the follower–follower (FF) pairs in the left temporo-parietal junction (TPJ), an area important for social mentalizing. Although communication frequency was higher for the LF pairs than for the FF pairs, the frequency of leader-initiated and follower-initiated communication did not differ significantly. Moreover, INS for the LF pairs was significantly higher during leader-initiated communication than during follower-initiated communications. In addition, INS for the LF pairs during leader-initiated communication was significantly correlated with the leaders’ communication skills and competence, but not their communication frequency. Finally, leadership could be successfully predicted based on INS as well as communication frequency early during the LGD (before half a minute into the task). In sum, this study found that leader emergence was characterized by high-level neural synchronization between the leader and followers and that the quality, rather than the frequency, of communications was associated with synchronization. These results suggest that leaders emerge because they are able to say the right things at the right time.

Glycogen recovery after exercise: junk food as good as sport supplements

I note this article because one of its authors, Chuck Dumke, now at the University of Montana, worked in my vision research laboratory at the University of Wisconsin in the 1990s, where he also studied kinesiology and sports performance. I'm passing this on to several friends who buy expensive post-exercise food supplements.

A variety of dietary choices are marketed to enhance glycogen recovery after physical activity. Past research informs recommendations regarding the timing, dose, and nutrient compositions to facilitate glycogen recovery. This study examined the effects of isoenergetic sport supplements (SS) vs. fast food (FF) on glycogen recovery and exercise performance. Eleven males completed two experimental trials in a randomized, counterbalanced order. Each trial included a 90-minute glycogen depletion ride followed by a 4-hour recovery period. Absolute amounts of macronutrients (1.54 ± 0.27 g·kg^-1 carbohydrate, 0.24 ± 0.04 g·kg fat^-1, and 0.18 ± 0.03g·kg protein^-1) as either SS or FF were provided at 0 and 2 hours. Muscle biopsies were collected from the vastus lateralis at 0 and 4 hours post exercise. Blood samples were analyzed at 0, 30, 60, 120, 150, 180, and 240 minutes post exercise for insulin and glucose, with blood lipids analyzed at 0 and 240 minutes. A 20k time-trial (TT) was completed following the final muscle biopsy. There were no differences in the blood glucose and insulin responses. Similarly, rates of glycogen recovery were not different across the diets (6.9 ± 1.7 and 7.9 ± 2.4 mmol·kgwet weight^-1·hr^-1 for SS and FF, respectively). There was also no difference across the diets for TT performance (34.1 ± 1.8 and 34.3 ± 1.7 minutes for SS and FF, respectively. These data indicate that short-term food options to initiate glycogen resynthesis can include dietary options not typically marketed as sports nutrition products such as fast food menu items.

Your friends know how long you will live.

An interesting study from Jackson et al. analyzing data from an east coast cohort of 600 people observed in the 1930s through 2013:

Although self-rated personality traits predict mortality risk, no study has examined whether one’s friends can perceive personality characteristics that predict one’s mortality risk. Moreover, it is unclear whether observers’ reports (compared with self-reports) provide better or unique information concerning the personal characteristics that result in longer and healthier lives. To test whether friends’ reports of personality predict mortality risk, we used data from a 75-year longitudinal study (the Kelly/Connolly Longitudinal Study on Personality and Aging). In that study, 600 participants were observed beginning in 1935 through 1938, when they were in their mid-20s, and continuing through 2013. Male participants seen by their friends as more conscientious and open lived longer, whereas friend-rated emotional stability and agreeableness were protective for women. Friends’ ratings were better predictors of longevity than were self-reports of personality, in part because friends’ ratings could be aggregated to provide a more reliable assessment. Our findings demonstrate the utility of observers’ reports in the study of health and provide insights concerning the pathways by which personality traits influence health.

Some details from the text of the article:

Between 1935 and 1938, 600 individuals (300 engaged heterosexual couples) began participating in the KCLS, a longitudinal study on personality and newly formed marriages. Participants were recruited through newspaper advertisements, other advertisements, and word of mouth in the state of Connecticut. The participants were primarily from middle-class backgrounds...Peer ratings were obtained from people that participants identified as knowing them well enough to provide accurate ratings; most of these friends had been in the participants’ wedding parties. Each participant named three to eight friends, and the majority of participants were rated by five friends...Self-ratings and peer ratings of personality were obtained using the 36-item Kelly Personality Rating Scale..we conducted a study to validate the PRS using more modern personality measures: the Big Five Inventory, the Iowa Personality Questionnaire, and the Mini International Personality Item Pool...The resulting five-factor solution reflected the Big Five factor structure. Extraversion was assessed with five items (e.g., quiet, popular), agreeableness with six items (e.g., courteous, sincere), conscientiousness with five items (e.g., persistent, reliable), emotional stability with four items (e.g., nervous, temperamental), and openness with four items (e.g., cultured, intelligent). Analyses indicated that the model adequately captured variation in modern Big Five composite scores...The average life span for men was 75.2 years (range = 23–98 years, SD = 15.5). The average life span for women was 81.3 years (range = 23–102 years, SD = 13.4). The 21 surviving participants had an average age of 97.2 years (SD = 2.1) in 2013.

Positive and negative emotions - valence is not value

Having done several recent posts on positive emotions,  and given the continuing rise of the "Be Happy" industry with its Be Happy Apps, I thought it appropriate to pass on this pithy and appropriate critique by June Gruber, of the idea that happiness is always good, sadness is always bad:

One idea in the study of emotion and its impact on psychological health is overdue for retirement: that negative emotions (like sadness or fear) are inherently bad or maladaptive for our psychological well-being, and positive emotions (like happiness or joy) are inherently good or adaptive. Such value judgments are to be understood, within the framework of affective science, as depending on whether an emotion impedes or fosters a person's ability to pursue goals, attain resources, and function effectively within society. Claims of the sort "sadness is inherently bad" or "happiness is inherently good" must be abandoned in light of burgeoning advances in the scientific study of human emotion.

Let's start with negative emotions. Early hedonic theories defined well-being, in part, as the relative absence of negative emotion. Empirically based treatments like cognitive-behavioral therapy also focus heavily on the reduction of negative feelings and moods as part of enhancing well-being. Yet a strong body of scientific work suggests that negative emotions are essential to our psychological well-being. Here are 3 examples. First, from an evolutionary perspective, negative emotions aid in our survival—they provide important clues to threats or problems that need our attention (such as an unhealthy relationship or dangerous situation). Second, negative emotions help us focus: they facilitate more detailed and analytic thinking, reduce stereotypic thinking, enhance eyewitness memory, and promote persistence on challenging cognitive tasks. Third, attempting to thwart or suppress negative emotions—rather than accept and appreciate them—paradoxically backfires and increases feelings of distress and intensifies clinical symptoms of substance abuse, overeating, and even suicidal ideation. Counter to these hedonic theories of well-being, negative emotions are hence not inherently bad for us. Moreover, the relative absence of them predicts poorer psychological adjustment.

Positive emotions have been conceptualized as pleasant or positively valenced states that motivate us to pursue goal-directed behavior. A longstanding scientific tradition has focused on the benefits of positive emotions, ranging from cognitive benefits such as enhanced creativity, social benefits like fostering relationship satisfaction and prosocial behavior, and physical health benefits such as enhanced cardiovascular health. From this work has emerged the assumption—both implicitly and explicitly—that positive emotional states should always be maximized. This has fueled the birth of entire subdisciplines and garnered momentous popular attention. But there's a mounting body of work against the claim that positive emotions are inherently good. First, positive emotions foster more self-focused behavior, including increased selfishness, greater stereotyping of out-group members, increased cheating and dishonesty, and decreased empathic accuracy in some contexts. Second, positive emotions are associated with greater distractibility and impaired performance on detail-oriented cognitive tasks. Third, because positive emotion may promote decreased inhibition it has been associated with greater risk-taking behaviors and mortality rates. Indeed, the presence of positive emotions is not always adaptive and sometimes can impede our well-being and even survival.

We are left to conclude that valence is not value: we cannot infer value judgments about emotions on the basis of their positive or negative valence. There is no intrinsic goodness or badness of an emotion merely because of its positivity or negativity, respectively. Instead, we must refine specific value-based determinants for an emotion's functionality. Towards this end, emerging research highlights critical variables to focus on. Importantly, the context in which an emotion unfolds can determine whether it helps or hinders an individual's goal, or which types of emotion regulatory strategies (reappraising or distracting) will best match the situation. Related, the degree of psychological flexibility someone possesses—including how quickly one can shift emotions or rebound from a stressful situation—promotes critical clinical health outcomes. Likewise, we find that psychological well-being is not entirely determined by the presence of one type or kind of an emotion but rather an ability to experience a rich diversity of both positive and negative emotions. Whether or not an emotion is "good" or "bad" seems to have surprisingly little to do with the emotion itself, but rather how mindfully we ride the ebbs and tides of our rich emotional life.

What happens in Vagus - compassion, positive emotion, vagal tone, and respiratory sinus arrhythmia,

The 10th cranial nerve, the vagus nerve, is distinctive to mammals and supports social engagement and nurturing behaviors as well as feeding, digesting, resting, breeding, etc. Its level of activity (tonus, or tension) is reflected in its inhibitory regulation of heartbeat, slowing it during exhalation and increasing it during inhalation. This change is heart rate is called respiratory sinus arrhythmia (RSA). Thus RSA serves as a measure of vagal tone. Dacher Keltner and collaborators have studied the relationship of vagal activity, reflected by RSA, to compassion and other prosocial emotions. I want to pass on the abstract from a preprint that can be downloaded here on studies correlating respiratory sinus arrhythmia with tonic (but not phasic) positive emotionality

Resting respiratory sinus arrhythmia (RSA_REST) indexes important aspects of individual differences in emotionality. In the present investigation, we address whether RSA_REST is associated with tonic positive or negative emotionality, and whether RSA_REST relates to phasic emotional responding to discrete positive emotion-eliciting stimuli. Across an 8-month, multiassessment study of first-year university students (n = 80), individual differences in RSA_REST were associated with positive but not negative tonic emotionality, assessed at the level of personality traits, long-term moods, the disposition toward optimism, and baseline reports of current emotional states. RSA_REST was not related to increased positive emotion, or stimulusspecific emotion, in response to compassion-, awe-, or pride-inducing stimuli. These findings suggest that resting RSA indexes aspects of a person’s tonic positive emotionality.

Reproducability in these studies may be an issue, because there is an apparent conflict between this abstracts report of no relationship between RSA_REST compassion-, awe-, or pride-inducing stimuli and the "increases in RSA during compassion" mentioned in Study 4 of the first link above. I might as well paste in that abstract also:

Compassion is an affective response to another’s suffering and a catalyst of prosocial behavior. In the present studies, we explore the peripheral physiological changes associated with the experience of compassion. Guided by long-standing theoretical claims, we propose that compassion is associated with activation in the parasympathetic autonomic nervous system through the vagus nerve. Across 4 studies, participants witnessed others suffer while we recorded physiological measures, including heart rate, respiration, skin conductance, and a measure of vagal activity called respiratory sinus arrhythmia (RSA). Participants exhibited greater RSA during the compassion induction compared with a neutral control (Study 1), another positive emotion (Study 2), and a prosocial emotion lacking appraisals of another person’s suffering (Study 3). Greater RSA during the experience of compassion compared with the neutral or control emotion was often accompanied by lower heart rate and respiration but no difference in skin conductance. In Study 4, increases in RSA during compassion positively predicted an established composite of compassion-related words, continuous self-reports of compassion, and nonverbal displays of compassion. Compassion, a core affective component of empathy and prosociality, is associated with heightened parasympathetic activity.

If you simply google "vagus nerve" you will find sites listing means of enhancing vagus activity and tone by self stimulation to improve mood and functioning, as an antidote to anxiety, etc.

The science of mind wandering.

I want to pass on this reference to an Ann. Rev. of Psychology article by Smallwood and Schooler, an extensive review and description of mind wandering, its disengagement from external input, its costs and benefits, its association with medial brain structures of the default mode network, its regulation by more lateral frontal executive control and external attention networks, etc. Here is the abstract, followed by a useful summary graphic:

Conscious experience is fluid; it rarely remains on one topic for an extended period without deviation. Its dynamic nature is illustrated by the experience of mind wandering, in which attention switches from a current task to unrelated thoughts and feelings. Studies exploring the phenomenology of mind wandering highlight the importance of its content and relation to meta-cognition in determining its functional outcomes. Examination of the information-processing demands of the mind-wandering state suggests that it involves perceptual decoupling to escape the constraints of the moment, its content arises from episodic and affective processes, and its regulation relies on executive control. Mind wandering also involves a complex balance of costs and benefits: Its association with various kinds of error underlines its cost, whereas its relationship to creativity and future planning suggest its potential value. Although essential to the stream of consciousness, various strategies may minimize the downsides of mind wandering while maintaining its productive aspects.

Evidence for the default mode network (DMN) as the substrate of the self-generated thought. The DMN is a large-scale brain network defined by the temporal correlation between activity in two core regions on the medial surface of the cortex, known as the posterior cingulate and medial prefrontal cortex. These regions form the core of the DMN (yellow) and interact with subnetworks including the medial temporal lobe subsystem (green) and the dorsal medial subsystem (blue). Meta-analyses using Neurosynth have shown that the core of this system tends to be engaged in self-referential processes, the medial temporal subsystem is engaged by episodic processes, and the dorsal medial subsystem is engaged by social processes. Together, these forms of thought are similar to the content of the self-generated thoughts that often occur during mind wandering, providing important evidence for the involvement of these regions in the mental content that occurs during mind wandering. Studies using experience sampling in conjunction with functional magnetic resonance imaging have shown that these regions show heightened activity during periods of task-unrelated thought (a–c). These brain images show that regions of the core aspects of the DMN exhibited greater activity during periods of task-unrelated thought. Regions: A, dorsal anterior cingulate cortex; B, ventral-medial medial pre-frontal cortex; C, posterior cingulate cortex; D, right temporal-parietal junction; E, dorsal medial prefrontal cortex; F, left rostral-lateral prefrontal cortex.

Manipulating moral decisions by exploiting eye gaze.

Here is a fascinating piece of work from Pärnamets et al.:

Eye gaze is a window onto cognitive processing in tasks such as spatial memory, linguistic processing, and decision making. We present evidence that information derived from eye gaze can be used to change the course of individuals’ decisions, even when they are reasoning about high-level, moral issues. Previous studies have shown that when an experimenter actively controls what an individual sees the experimenter can affect simple decisions with alternatives of almost equal valence. Here we show that if an experimenter passively knows when individuals move their eyes the experimenter can change complex moral decisions. This causal effect is achieved by simply adjusting the timing of the decisions. We monitored participants’ eye movements during a two-alternative forced-choice task with moral questions. One option was randomly predetermined as a target. At the moment participants had fixated the target option for a set amount of time we terminated their deliberation and prompted them to choose between the two alternatives. Although participants were unaware of this gaze-contingent manipulation, their choices were systematically biased toward the target option. We conclude that even abstract moral cognition is partly constituted by interactions with the immediate environment and is likely supported by gaze-dependent decision processes. By tracking the interplay between individuals, their sensorimotor systems, and the environment, we can influence the outcome of a decision without directly manipulating the content of the information available to them.

We hypothesized that participants’ eye gaze reveals their decision process owing to general coupling between sensorimotor decision processes. By using a gaze-contingent probe and selecting when a decision is prompted the resulting choice can be biased toward a randomly predetermined option.