Climate change and human crisis

In case you need anything further to depress you about our impending climate changes, Zhang et al. do a more fine-grained analysis of the effect of past episodes of climate catastrophe by bringing more quantitative scrutiny to try to confirm what scholars have qualitatively noted: that massive social disturbance, societal collapse, and population collapse often coincided with great climate change in America, the Middle East, China, and many other countries in preindustrial times.

Recent studies have shown strong temporal correlations between past climate changes and societal crises. However, the specific causal mechanisms underlying this relation have not been addressed. We explored quantitative responses of 14 fine-grained agro-ecological, socioeconomic, and demographic variables to climate fluctuations from A.D. 1500–1800 in Europe (a period that contained both periods of harmony and times of crisis). Results show that cooling from A.D. 1560–1660 caused successive agro-ecological, socioeconomic, and demographic catastrophes, leading to the General Crisis of the Seventeenth Century. We identified a set of causal linkages between climate change and human crisis. Using temperature data and climate-driven economic variables, we simulated the alternation of defined “golden” and “dark” ages in Europe and the Northern Hemisphere during the past millennium. Our findings indicate that climate change was the ultimate cause, and climate-driven economic downturn was the direct cause, of large-scale human crises in preindustrial Europe and the Northern Hemisphere.

Their data support the causal links shown in this figure:

Figure - Set of causal linkages from climate change to large-scale human crisis in preindustrial Europe. The terms in bold black type are sectors, and terms in red type within parentheses are variables that represent the sector. The thickness of the arrow indicates the degree of average correlation

Narcissistic Leaders and Group Performance

Nevica et al. point to yet another case where reality is at odds with perceptions:

Although narcissistic individuals are generally perceived as arrogant and overly dominant, they are particularly skilled at radiating an image of a prototypically effective leader. As a result, they tend to emerge as leaders in group settings. Despite people’s positive perceptions of narcissists as leaders, it was previously unknown if and how leaders’ narcissism is related to the performance of the people they lead. In this study, we used a hidden-profile paradigm to investigate this question and found evidence for discordance between the positive image of narcissists as leaders and the reality of group performance. We hypothesized and found that although narcissistic leaders are perceived as effective because of their displays of authority, a leader’s narcissism actually inhibits information exchange between group members and thereby negatively affects group performance. Our findings thus indicate that perceptions and reality can be at odds and have important practical and theoretical implications.

The evolution of cognition

It is now commonly recognized that high-level cognitive function is not limited to primate lineages and like many other traits, is shaped by selection imposed by ecological and environmental demands. MacClean et al. (PDF here) propose that a merger of the fields of comparative psychology and phylogenetics would greatly improve our ability to understand the forces that drive cognitive evolution:

Now more than ever animal studies have the potential to test hypotheses regarding how cognition evolves. Comparative psychologists have developed new techniques to probe the cognitive mechanisms underlying animal behavior, and they have become increasingly skillful at adapting methodologies to test multiple species. Meanwhile, evolutionary biologists have generated quantitative approaches to investigate the phylogenetic distribution and function of phenotypic traits, including cognition. In particular, phylogenetic methods can quantitatively (1) test whether specific cognitive abilities are correlated with life history (e.g., lifespan), morphology (e.g., brain size), or socio-ecological variables (e.g., social system), (2) measure how strongly phylogenetic relatedness predicts the distribution of cognitive skills across species, and (3) estimate the ancestral state of a given cognitive trait using measures of cognitive performance from extant species. Phylogenetic methods can also be used to guide the selection of species comparisons that offer the strongest tests of a priori predictions of cognitive evolutionary hypotheses (i.e., phylogenetic targeting). Here, we explain how an integration of comparative psychology and evolutionary biology will answer a host of questions regarding the phylogenetic distribution and history of cognitive traits, as well as the evolutionary processes that drove their evolution.

Very brief meditation training produces brain changes associated with positive emotions.

It is known that the ratio of left frontal to right frontal lobe activation is relatively higher in individuals with higher positive affect - this effect can be monitored by e.e.g. electrodes placed on the head. (In light of Gilbert's recent observation that "A wandering mind is an unhappy mind," I wonder if resting frontal asymmetry correlates with mind wandering....) Davidson and colleagues have shown that a fairly rigorous 8-week meditation training program can cause a significant increase the left-sided anterior activation associated with positive affect. Now Moyer et al. at the Univ. of Wisconsin, Stout, claim that a much briefer intervention can be effective. Participants..

...who did not differ in frontal EEG asymmetry before training, were randomly assigned to the meditation training (MT; n = 11) or waiting-list (WL; n = 10) group. MT participants were told that nine 30-min sessions of meditation instruction were available to them and were encouraged to attend as many sessions as possible. A standard protocol was used to measure positive and negative affect before and after 15 min of attempted focused-attention meditation according to provided instructions (“relax with your eyes closed, and focus on the flow of your breath at the tip of your nose; if a random thought arises, acknowledge the thought and then simply let it go by gently bringing your attention back to the flow of your breath”).

Some results from the paper:

MT and WL participants did not differ in frontal EEG asymmetry before training, paired t(13) = 0.16, r = −.01, p = .88, d = 0.06 (see Figure, click to enlarge). During training, MT participants attended an average of 6.73 (SD = 1.35, range = 4−8) instruction sessions and reported engaging in independent 15-min intervals of meditation an average of 2.24 (SD = 1.01, range = 1−5) times per week. MT participants averaged 6 hr 13 min of training (SD = 1 hr 35 min, range = 3 hr 15 min to 9 hr 8 min) across the 5 weeks. After training, MT participants had significantly greater leftward shift in frontal EEG asymmetry than WL participants did across all time points, paired t(13) = 10.80, r = .40, p less than .001, d = 3.18 (see Figure).

Comparison with the control group (WL) seems somewhat shakey. They were doing nothing except knowing they would be offered training after the first group? What about being given an amount for some other kind of 'instruction' (religious, philosophical, whatever) for the same intervals?

Some clips from the discussion:

With training, focused-attention meditation shifts frontal EEG asymmetry toward a pattern associated with positive, approach-oriented emotions. Further, this shift does not require hundreds or even dozens of hours of practice. Individual MT participants in this study averaged only 5 to 16 min of active training (i.e., instruction, independent practice) per day across 5 weeks, but still exhibited a strong change in EEG asymmetry compared with the WL group. Our results suggest that the benefits of meditation may be more accessible than was previously believed. However, this study does not indicate if such asymmetry is pervasive or is limited to the time of meditation and the brief intervals that immediately surround it...We suggest two explanations for the increase in EEG asymmetry that emerged after so little training. First, our MT participants were able to decide when to practice, and for how long; this flexibility allowed them to determine for themselves when they would be most receptive to meditation, and choosing advantageous times may have heightened the efficacy of the meditation. Second, the small amount of active practice participants reported may have enabled a larger amount of passive practice to occur spontaneously, without a conscious decision to meditate; such passive practice may have strengthened the effects of meditation. This latter explanation is consistent with reports from some MT participants that they occasionally found themselves focusing their attention in the way they had been taught, even without having set out to do so.

Adolescent brain changes while viewing media violence

Strenziok et al. (open access) note a habituation and desensitization of adolescent emotional network brain responses to TV violence, which raises the obvious concern that diminishing the linking of the consequences of aggression with an emotional response might promote aggressive attitudes and behavior.

Adolescents spend a significant part of their leisure time watching TV programs and movies that portray violence. It is unknown, however, how the extent of violent media use and the severity of aggression displayed affect adolescents’ brain function. We investigated skin conductance responses, brain activation and functional brain connectivity to media violence in healthy adolescents. In an event-related functional magnetic resonance imaging experiment, subjects repeatedly viewed normed videos that displayed different degrees of aggressive behavior. We found a downward linear adaptation in skin conductance responses with increasing aggression and desensitization towards more aggressive videos. Our results further revealed adaptation in a fronto-parietal network including the left lateral orbitofrontal cortex (lOFC), right precuneus and bilateral inferior parietal lobules, again showing downward linear adaptations and desensitization towards more aggressive videos. Granger causality mapping analyses revealed attenuation in the left lOFC, indicating that activation during viewing aggressive media is driven by input from parietal regions that decreased over time, for more aggressive videos. We conclude that aggressive media activates an emotion–attention network that has the capability to blunt emotional responses through reduced attention with repeated viewing of aggressive media contents, which may restrict the linking of the consequences of aggression with an emotional response, and therefore potentially promotes aggressive attitudes and behavior.

A Fauré Nocturne - new born chicks would like it....

I'm finding some of the Gabriel Fauré Noctures very pleasant. Here is Nocturne no. 3, op. 33. And, the abstract following the video is relevant to the debate over whether our preference of consonant music of this sort is rooted in acoustic properties important to the auditory system or is acquired through enculturation. Italian researchers find newly hatched domestic chicks show a spontaneous preference for a visual imprinting object associated with consonant sound intervals over an identical object associated with dissonant sound intervals. This suggests that preference for harmonic relationships between frequency components may be related to the prominence of harmonic spectra in biological sounds in natural environments.



Here is the abstract from Chiandetti and
Vallortigara1:

The question of whether preference for consonance is rooted in acoustic properties important to the auditory system or is acquired through enculturation has not yet been resolved. Two-month-old infants prefer consonant over dissonant intervals, but it is possible that this preference is rapidly acquired through exposure to music soon after birth or in utero. Controlled-rearing studies with animals can help shed light on this question because such studies allow researchers to distinguish between biological predispositions and learned preferences. In the research reported here, we found that newly hatched domestic chicks show a spontaneous preference for a visual imprinting object associated with consonant sound intervals over an identical object associated with dissonant sound intervals. We propose that preference for harmonic relationships between frequency components may be related to the prominence of harmonic spectra in biological sounds in natural environments.

Our "divided brain" - an animated tutorial.

A loyal mindblog reader has pointed me to an animated lecture, by psychiatrist and writer Iain McGilchrist, that is quite fun to watch. It starts by briefly describing and debunking the pop-psychology about our split brains that reached a peak in the 1970s (for imagination and reason you in fact need BOTH hemispheres), and then proceeds through a lucid explanation of the evolution and function of our brain's hemispheric asymmetry, and the advanced functions made possible by the inhibitory functions of our frontal lobes. McGilchrist cites and illustrates Pascal's point that "The end point of rationality is to demonstrate the limits of rationality." The last few minutes of the 11 minute video are notably informative and hysterically funny. At the conclusion McGilchrist cites Einstein's comment that "The intuitive mind is a sacred gift and the rational mind is a faithful servant," noting that we have created a society that honors the servant. (You should check out the RSA organization's website, which points to a number of lectures in this style.)

Women's memory enhanced by lower male voice pitch.

Women are attracted to low male voices, and a prevailing idea is that this is relevant to mate selection. Kevin Allen and colleagues now show that they are also more likely to remember what those low voices say to them. (It makes sense that memory should be sensitive towards content of adaptive value and thus help us to act in ways that enhance our reproductive fitness):

From a functionalist perspective, human memory should be attuned to information of adaptive value for one’s survival and reproductive fitness. While evidence of sensitivity to survival-related information is growing, specific links between memory and information that could impact upon reproductive fitness have remained elusive. Here, in two experiments, we showed that memory in women is sensitive to male voice pitch, a sexually dimorphic cue important for mate choice because it not only serves as an indicator of genetic quality, but may also signal behavioural traits undesirable in a long-term partner. In a first experiment, we found that women’s visual object memory is significantly enhanced when an object’s name is spoken during encoding in a masculinised (i.e., lower-pitch) versus feminised (i.e., higher-pitch) male voice, but that no analogous effect occurs when women listen to other women’s voices. A second experiment replicated this pattern of results, additionally showing that lowering and raising male voice pitch enhanced and impaired women’s memory, respectively, relative to a baseline (i.e., unmanipulated) voice condition. The modulatory effect of sexual dimorphism cues in the male voice may reveal a mate-choice adaptation within women’s memory, sculpted by evolution in response to the dilemma posed by the double-edged qualities of male masculinity.

Human genes still evolve rapidly

A Harvard group has found evolution in response to natural selection in a contemporary human population, showing a dramatic decrease in age of reproduction in a defined population since 1720. Context on the location of their study:

Ile aux Coudres is a 34-km2 island located ∼80 km to the northeast of Québec City along the St. Lawrence River (Canada). Thirty families settled on the island between 1720 and 1773 and the population reached 1,585 people by the 1950s. This population is ideal to study the genetic basis of life-history traits (LHTs). First, church registers provide exceptionally detailed records of dates of births, marriages, and deaths. Second, the long-term data and endogamy (marriages within the population) provide a deep and intricate pedigree to facilitate the separation of genetic and environmental influences on LHTs. Third, the population was very homogeneous among families, particularly in traits known to correlate with the timing of reproduction (social class, education, and religion). In addition, the split of resources among families was quite even due to the type of land distribution, and the number of professions was limited. This relative homogeneity should minimize confounding socioeconomic or shared environmental influences within quantitative genetic analyses.

Here is their abstract:

It is often claimed that modern humans have stopped evolving because cultural and technological advancements have annihilated natural selection. In contrast, recent studies show that selection can be strong in contemporary populations. However, detecting a response to selection is particularly challenging; previous evidence from wild animals has been criticized for both applying anticonservative statistical tests and failing to consider random genetic drift. Here we study life-history variation in an insular preindustrial French-Canadian population and apply a recently proposed conservative approach to testing microevolutionary responses to selection. As reported for other such societies, natural selection favored an earlier age at first reproduction (AFR) among women. AFR was also highly heritable and genetically correlated to fitness, predicting a microevolutionary change toward earlier reproduction. In agreement with this prediction, AFR declined from about 26–22 y over a 140-y period. Crucially, we uncovered a substantial change in the breeding values for this trait, indicating that the change in AFR largely occurred at the genetic level. Moreover, the genetic trend was higher than expected under the effect of random genetic drift alone. Our results show that microevolution can be detectable over relatively few generations in humans and underscore the need for studies of human demography and reproductive ecology to consider the role of evolutionary processes.

The brain's fountain of youth

Williams points to an article that suggests that Dracula may have gotten it right. Young blood can restore an aging body. Giving young blood to older mice is know to boost their immune system and muscle function, and now it turns out that it also causes the synthesis of new nerve cells, boosting the number of cells in the hippocampus involved in memory formation. Conversely, serum from older mice decreases the number of these memory cells in younger mice. Wyss-Coray and collaborators find a blood borne protein (cytokine CCL11) that increases with aging and inhibits synthesis of new nerve cells. Factors stimulating neurogenesis are being sought. Here is their abstract:

In the central nervous system, ageing results in a precipitous decline in adult neural stem/progenitor cells and neurogenesis, with concomitant impairments in cognitive functions. Interestingly, such impairments can be ameliorated through systemic perturbations such as exercise1. Here, using heterochronic parabiosis we show that blood-borne factors present in the systemic milieu can inhibit or promote adult neurogenesis in an age-dependent fashion in mice. Accordingly, exposing a young mouse to an old systemic environment or to plasma from old mice decreased synaptic plasticity, and impaired contextual fear conditioning and spatial learning and memory. We identify chemokines—including CCL11 (also known as eotaxin)—the plasma levels of which correlate with reduced neurogenesis in heterochronic parabionts and aged mice, and the levels of which are increased in the plasma and cerebrospinal fluid of healthy ageing humans. Lastly, increasing peripheral CCL11 chemokine levels in vivo in young mice decreased adult neurogenesis and impaired learning and memory. Together our data indicate that the decline in neurogenesis and cognitive impairments observed during ageing can be in part attributed to changes in blood-borne factors.

"Neurotrash"

In The Chronicle of Higher Education Marc Parry notes the crusade of Raymond Tallis to throw out the "Neurotrash." This is the goal of his new book "Aping Mankind: Neuromania, Darwinitis, and the Misrepresentation of Humanity" (McGill-Queen's University Press). Parry describes a Tallis lecture that seeks to demolish

…two "pillars of unwisdom." The first, "neuromania," is the notion that to understand people you must peer into the "intracranial darkness" of their skulls with brain-scanning technology. The second, "Darwinitis," is the idea that Charles Darwin's evolutionary theory can explain not just the origin of the human species—a claim Tallis enthusiastically accepts—but also the nature of human behavior and institutions….Those trends, as Tallis sees them, are like "intellectual illnesses" metastasizing from academic labs into popular culture. He sees the symptoms in neuro-economic thinkers who explain our susceptibility to subprime mortgages by describing how our brains evolved to favor short-term rewards. He sees them in philosophers who claim that our primate minds admire paintings of landscapes that would have supported hunting and gathering. He sees it in neurotheologians who preach that "God is a tingle in the 'God spot' in the brain."

The points Tallis makes are good, much of the press description of 'love spots in the brain' , etc. is nonsense…but Tallis does seem to throw out the baby with the bathwater. How could we make sense of the irrational social behaviors described in the previous two mindblog posts this week outside of an evolutionary framework, and how do we explain that activities of certain brain areas, when perturbed by strokes, electrical stimulation, or drugs do alter fairly discrete classes of behaviors?

Brief neuroscience video-tutorials

I recently received an email from Aki Nikolaidis, a neuroscience graduate student at the University of Illinois, asking me to have a look some brief instructional videos he had been making over the past several years. I took a look, and found them quite engaging. Here they are:

Fluid Intelligence

Consciousness and Free Will

Non-conscious Information Processing

Electroencephalogram (EEG)

Working Memory Training

The science of irrationality.

As a followup to yesterday's post on how common sense, ideology and intuition lead us astray in our attempts to fix social problems - while social intervention programs that have been validated by true randomized experiments are ignored - I point to Jonah Lehrer's brief review of Daniel Kahneman's new book "Thinking, Fast and Slow.", which describes his work on evolved blind spots in our rational processes which appear to be virtually impossible to fix, even though we understand that they are there.

When people face an uncertain situation, they don't carefully evaluate the information or look up relevant statistics. Instead, their decisions depend on mental short cuts, which often lead them to make foolish decisions. The short cuts aren't a faster way of doing the math; they're a way of skipping the math altogether...The biases and blind-spots identified by Messrs. Kahneman and Tversky aren't symptoms of stupidity. They're an essential part of our humanity, the inescapable byproducts of a brain that evolution engineered over millions of years.

Consider the overconfidence bias, which drives many of our mistakes in decision-making. The best demonstration of the bias comes from the world of investing. Although many fund managers charge high fees to oversee stock portfolios, they routinely fail a basic test of skill: persistent achievement. As Mr. Kahneman notes, the year-to-year correlation between the performance of the vast majority of funds is barely above zero, which suggests that most successful managers are banking on luck, not talent...This shouldn't be too surprising. The stock market is a case study in randomness, a system so complex that it's impossible to predict. Nevertheless, professional investors routinely believe that they can see what others can't. The end result is that they make far too many trades, with costly consequences.

We like to see ourselves as a Promethean species, uniquely endowed with the gift of reason. But Mr. Kahneman's simple experiments reveal a very different mind, stuffed full of habits that, in most situations, lead us astray. Though overconfidence may encourage us to take necessary risks—Mr. Kahneman calls it the "engine of capitalism"—it's generally a dangerous (and expensive) illusion.

What's even more upsetting is that these habits are virtually impossible to fix. As Mr. Kahneman himself admits, "My intuitive thinking is just as prone to overconfidence, extreme predictions and the planning fallacy as it was before I made a study of these issues."...Even when we know why we stumble, we still find a way to fall.

The science of psychological change

In the Oct 14 issue of Science Magazine
Geoffrey L. Cohen reviews Timothy Wilson's new book "Redirect: The Surprising New Science of Psychological Change." The book reviews success stories in social psychology, and I thought it would be worthwhile to pass on a few clips from that review:

There are interventions that harness the power of expressive writing and volunteerism to improve happiness and health and to lessen rates of teen pregnancy. There are interventions that reduce student failure and close gaps between minority and nonminority students by inculcating in them core positive beliefs that sustain them through hardship, such as the belief that intelligence is not a fixed entity but rather like a muscle that grows with effort. There are interventions that improve intertribal trust in Rwanda by modeling cooperative intergroup relations through radio soap operas. In the United States, interventions that defuse blacks' and whites' fear of interracial rejection increase their likelihood of becoming friends. And...there are studies that cleverly manipulate social norms to reduce teen alcohol use and encourage energy conservation.

And notes:

What these interventions share is that they are grounded in science, found effective in randomized experiments, have surprisingly large and durable effects—and, by and large, aren't used. Over and over, Wilson writes, schools, government agencies, and workplaces opt for interventions that not only have never been subjected to experimental test but also, when they finally are, often yield null and even negative effects. These interventions are usually based on a combination of intuition, ideology, and good intentions. Wilson critiques several popular but unwise interventions: Drug Abuse Resistance Education (D.A.R.E., implemented in 75% of the school districts in the United States), “scared straight,” certain forms of posttraumatic grief counseling, many commonplace diversity training programs, and the self-help and positive thinking industry in general ["The Secret" book receives sustained criticism]. These are analogous, Wilson writes, to the practices of leeching and blood-letting before the scientific method took hold in medicine.

Wilson uses the thought-provoking metaphor of “story editing” to describe the ingredient common to many of the successful interventions he reviews. They alter the narratives people tell themselves about their world and their place in it: Is it safe or threatening? Do I belong or not? Am I capable or not? During sensitive periods, people's storytelling can be redirected and the change can build on itself over time. Amend the opening sentence of the story of your transition to college, or to a new job, and the arc of your story may be entirely different from what it would have been otherwise. This helps explain why seemingly simple interventions, such as writing about a traumatic experience, or volunteering for a humanitarian cause, improve health and well-being. They give people an organizing narrative that puts their lives in an optimistic context.

Dissolution of the social contract

I've been meaning to point to a very cogent essay by Marmor and Mashaw on why conditions for recovery from the great depression of the early 1930's were more propitious than those that prevail in our current recession - which promises to be very prolonged.

...there is a crucial difference between then and now: the words that our political leaders use to talk about our problems have changed. Where politicians once drew on a morally resonant language of people, family and shared social concern, they now deploy the cold technical idiom of budgetary accounting...This is more than a superficial difference in rhetoric. It threatens to deprive us of the intellectual resources needed to address today’s problems.

From the 1930s to the 1960s...American public discourse was filled with references to the social circumstances of average citizens, our common institutions and our common history. Over the last five decades, that discourse has changed in ways that emphasize individual choice, agency and preferences. The language of sociology and common culture has been replaced by the language of economics and individualism.

In 1934, the government was us. We had shared circumstances, shared risks and shared obligations. Today the government is the other — not an institution for the achievement of our common goals, but an alien presence that stands between us and the realization of individual ambitions. Programs of social insurance have become “entitlements,” a word apparently meant to signify not a collectively provided and cherished basis for family-income security, but a sinister threat to our national well-being.

Over the last 50 years we seem to have lost the words — and with them the ideas — to frame our situation appropriately.

Differences in reality monitoring correlate with prefrontal cortex variations

Here is an intriguing bit of work from Buda et al.:

Much recent interest has centered on understanding the relationship between brain structure variability and individual differences in cognition, but there has been little progress in identifying specific neuroanatomical bases of such individual differences. One cognitive ability that exhibits considerable variability in the healthy population is reality monitoring; the cognitive processes used to introspectively judge whether a memory came from an internal or external source (e.g., whether an event was imagined or actually occurred). Neuroimaging research has implicated the medial anterior prefrontal cortex (PFC) in reality monitoring, and here we sought to determine whether morphological variability in a specific anteromedial PFC brain structure, the paracingulate sulcus (PCS), might underlie performance. Fifty-three healthy volunteers were selected on the basis of MRI scans and classified into four groups according to presence or absence of the PCS in their left or right hemisphere. The group with absence of the PCS in both hemispheres showed significantly reduced reality monitoring performance and ability to introspect metacognitively about their performance when compared with other participants. Consistent with the prediction that sulcal absence might mean greater volume in the surrounding frontal gyri, voxel-based morphometry revealed a significant negative correlation between anterior PFC gray matter and reality monitoring performance. The findings provide evidence that individual differences in introspective abilities like reality monitoring may be associated with specific structural variability in the PFC.

Examples of prominent (left) and absent (right) PCS classifications. In the left panel, PCS is indicated by the red arrow.

Merging emotional information from voice and faces in the brain.

Klasen et al. find the ventral posterior cingulate to be a central structure for supramodal representation of complex emotional information. The left amygdala reflects input of happy stimuli from multiple sensory inputs:

Supramodal representation of emotion and its neural substrates have recently attracted attention as a marker of social cognition. However, the question whether perceptual integration of facial and vocal emotions takes place in primary sensory areas, multimodal cortices, or in affective structures remains unanswered yet. Using novel computer-generated stimuli, we combined emotional faces and voices in congruent and incongruent ways and assessed functional brain data (fMRI) during an emotional classification task. Both congruent and incongruent audiovisual stimuli evoked larger responses in thalamus and superior temporal regions compared with unimodal conditions. Congruent emotions were characterized by activation in amygdala, insula, ventral posterior cingulate (vPCC), temporo-occipital, and auditory cortices; incongruent emotions activated a frontoparietal network and bilateral caudate nucleus, indicating a greater processing load in working memory and emotion-encoding areas. The vPCC alone exhibited differential reactions to congruency and incongruency for all emotion categories and can thus be considered a central structure for supramodal representation of complex emotional information. Moreover, the left amygdala reflected supramodal representation of happy stimuli. These findings document that emotional information does not merge at the perceptual audiovisual integration level in unimodal or multimodal areas, but in vPCC and amygdala.

Measuring Zeitgeist from the Tweet stream.

Golder and Macy have analyzed more than 509 million Twitter posts by 2.4 million users over a 2-year period in order to study collective mood (using Twitter to track the mood of nations sort of like using satellites to track the state of the atmosphere!). They used a freely available protocol provided by Twitter to download tweets originating from 84 countries between February 2008 and January 2010, and searched these messages for roughly 1000 words on a tried-and-tested list of words associated with positive (agree, fantastic, super) and negative (afraid, mad, panic) emotion. Despite very different cultures, geographies, and religions, the U.S., Canada, the UK, Australia, India, and English-speaking Africa all showed similar mood rhythms:

We identified individual-level diurnal and seasonal mood rhythms in cultures across the globe, using data from millions of public Twitter messages. We found that individuals awaken in a good mood that deteriorates as the day progresses—which is consistent with the effects of sleep and circadian rhythm—and that seasonal change in baseline positive affect varies with change in daylength. People are happier on weekends, but the morning peak in positive affect is delayed by 2 hours, which suggests that people awaken later on weekends.

A graphic from the article:

Hourly changes in individual affect broken down by day of the week (top, positive affect, PA; bottom,  negative affect, NA). Each series shows mean affect (black lines) and 95% confidence interval (colored regions). (Experimental psychologists have repeatedly demonstrated that positive and negative affect are independent dimensions. Positive affect (PA) includes enthusiasm, delight, activeness, and alertness, whereas negative affect (NA) includes distress, fear, anger, guilt, and disgust)

Fatherhood decreases testosterone.

Gettler et al. find that, in a community-based sample from the Philippines, men with higher testosterone level are more likely to marry than men with lower testosterone; that men who marry and become fathers experience declines in testosterone; and that men who provide more paternal care have lower testosterone levels than fathers who provide less care:

In species in which males care for young, testosterone (T) is often high during mating periods but then declines to allow for caregiving of resulting offspring. This model may apply to human males, but past human studies of T and fatherhood have been cross-sectional, making it unclear whether fatherhood suppresses T or if men with lower T are more likely to become fathers. Here, we use a large representative study in the Philippines (n = 624) to show that among single nonfathers at baseline (2005) (21.5 ± 0.3 y), men with high waking T were more likely to become partnered fathers by the time of follow-up 4.5 y later (P < 0.05). Men who became partnered fathers then experienced large declines in waking (median: −26%) and evening (median: −34%) T, which were significantly greater than declines in single nonfathers (P < 0.001). Consistent with the hypothesis that child interaction suppresses T, fathers reporting 3 h or more of daily childcare had lower T at follow-up compared with fathers not involved in care (P < 0.05). Using longitudinal data, these findings show that T and reproductive strategy have bidirectional relationships in human males, with high T predicting subsequent mating success but then declining rapidly after men become fathers. Our findings suggest that T mediates tradeoffs between mating and parenting in humans, as seen in other species in which fathers care for young. They also highlight one likely explanation for previously observed health disparities between partnered fathers and single men.

Mimicry can foster both rapport and threat.

Liu does experiments that illustrate two aspects of mimicry. Mimicry can bond people by fostering rapport and liking, but appears to have the opposite effect if participants in an interaction are primed by reminders of money. Money-primed participants liked a mimicking interaction partner less than they liked a nonmimicking partner, an effect that appears to have been due to enhanced feelings of threat. Their observations are consonant with studies that have shown that reminders of money elicit a self-sufficient state characterized by two tendencies: First, eagerness to pursue personal goals and freedom, persisting longer than others on difficult tasks and hesitating to ask for help; and second, acting more insensitive to others, desiring solo versus activities and showing more indifference to social exclusion.