Getting the rhythm to suppress Alzheimer's

An interesting brief open source review by Lynne Peeples in PNAS describes experiments on mice and humans showing that visual and sound stimulation in the e.e.g gamma frequency range (30-80 Hertz, or cycles/sec, peaking at 40 Hz) elicits gamma frequency brain oscillation, enhance cognition, and diminishes levels of the amyloid plaques and tau protein tangles associated with Alzheismer's. The article is worth a read, and I pass on just a bit of a background paragraph:

Brain rhythms are known to participate in all forms of cognition. And changes of brain rhythms appear to be implicated in all forms of neurological disease...Growing evidence indicates that neurons in many animals, including humans, can strongly synchronize in the gamma range of frequencies—between 30 and 80 hertz, and peaking around 40 hertz. As far back as a 1955 study of meditating yogis, researchers have associated gamma waves with peak concentration and high levels of cognitive functioning. Studies in the last decade that manipulated brain rhythms in lab animals and humans have confirmed the impact of those rhythms on cognition and disease. Researchers have also found that fewer neurons fire together at this rate in patients with Alzheimer’s disease or other neurological conditions, suggesting that gamma rhythms may play a role in the cognitive impairments associated with such disorders.

Rice-farming predicts tigher social norms, less innovative thinking, worldwide

From Talhelm and English (open source):

Data recently published in PNAS mapped out regional differences in the tightness of social norms across China [R. Y. J. Chua, K. G. Huang, M. Jin, Proc. Natl. Acad. Sci. U.S.A. 116, 6720–6725 (2019)]. Norms were tighter in developed, urbanized areas and weaker in rural areas. We tested whether historical paddy rice farming has left a legacy on social norms in modern China. Premodern rice farming could plausibly create strong social norms because paddy rice relied on irrigation networks. Rice farmers coordinated their water use and kept track of each person’s labor contributions. Rice villages also established strong norms of reciprocity to cope with labor demands that were twice as high as dryland crops like wheat. In line with this theory, China’s historically rice-farming areas had tighter social norms than wheat-farming areas, even beyond differences in development and urbanization. Rice–wheat differences were just as large among people in 10 neighboring provinces (n = 3,835) along the rice–wheat border. These neighboring provinces differ sharply in rice and wheat, but little in latitude, temperature, and other potential confounding variables. Outside of China, rice farming predicted norm tightness in 32 countries around the world. Finally, people in rice-farming areas scored lower on innovative thinking, which tends to be lower in societies with tight norms. This natural test case within China might explain why East Asia—historically reliant on rice farming—has tighter social norms than the wheat-farming West.

Stable isotopes in hair reveal dietary divergence related to socioeconomic status and health

From Ehleringer et al.:

Carbon and nitrogen isotope ratios in hair sampled from 65 communities across the central and intermountain regions of the United States and more intensively throughout 29 ZIP codes in the Salt Lake Valley, Utah, revealed a dietary divergence related to socioeconomic status as measured by cost of living, household income, and adjusted gross income. Corn-fed, animal-derived proteins were more common in the diets of lower socioeconomic status populations than were plant-derived proteins, with individual estimates of animal-derived protein diets as high as 75%; United States towns and cities averaged 57%. Similar patterns were seen across the socioeconomic status spectrum in the Salt Lake Valley. It is likely that corn-fed animal proteins were associated with concentrated animal-feeding operations, a common practice for industrial animal production in the United States today. Given recent studies highlighting the negative impacts of animal-derived proteins in our diets, hair carbon isotope ratios could provide an approach for scaling assessments of animal-sourced foods and health risks in communities across the United States.

Gaze deflection reveals how gaze cueing is tuned to extract the mind behind the eyes

Here is a fascinating bit from Colombatto et al.:  

Significance

We report an empirical study of gaze deflection—a common experience in which you turn to look in a different direction when someone “catches” you staring at them. We show that gaze cueing (the automatic orienting of attention to locations at which others are looking) is far weaker for such displays, even when the actual eye and head movements are identical to more typical intentional gazes. This demonstrates how gaze cueing is driven by the perception of minds, not eyes, and it serves as a case study of both how social dynamics can shape visual attention in a sophisticated manner and how vision science can contribute to our understanding of common social phenomena.

Abstract

Suppose you are surreptitiously looking at someone, and then when they catch you staring at them, you immediately turn away. This is a social phenomenon that almost everyone experiences occasionally. In such experiences—which we will call gaze deflection—the “deflected” gaze is not directed at anything in particular but simply away from the other person. As such, this is a rare instance where we may turn to look in a direction without intending to look there specifically. Here we show that gaze cues are markedly less effective at orienting an observer’s attention when they are seen as deflected in this way—even controlling for low-level visual properties. We conclude that gaze cueing is a sophisticated mental phenomenon: It is not merely driven by perceived eye or head motions but is rather well tuned to extract the “mind” behind the eyes.

Effects of lockdown on human sleep and chronotype during the COVID-19 pandemic

An open source article in Current Biology from Leone et al., the summary:

The COVID-19 pandemic resulted in many countries imposing a lockdown, which in turn reduces sunlight exposure and alters daily social schedules. Since these are the main entrainment factors for biological rhythms, we hypothesized that the lockdown may have affected sleep and circadian rhythms. We indeed show that participants slept longer and later during lockdown weekdays, and exhibited lower levels of social jetlag. While this may seem to be an overall improvement of sleep conditions, chronotype was also delayed under the lockdown. This signature of a weaker light–dark cycle should be monitored attentively since it may progressively cause disruptive effects on sleep and circadian rhythms, affecting human performance and health.

A model shows herd immunity to COVID can be achieved at a population-wide infection rate of ~40%

I pass on the editor's summary and the abstract for a open source article by Britton et al.:  

Heterogeneity and herd immunity

In response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), some politicians have been keen to exploit the idea of achieving herd immunity. Countering this possibility are estimates derived from work on historical vaccination studies, which suggest that herd immunity may only be achieved at an unacceptable cost of lives. Because human populations are far from homogeneous, Britton et al. show that by introducing age and activity heterogeneities into population models for SARS-CoV-2, herd immunity can be achieved at a population-wide infection rate of ∼40%, considerably lower than previous estimates. This shift is because transmission and immunity are concentrated among the most active members of a population, who are often younger and less vulnerable. If nonpharmaceutical interventions are very strict, no herd immunity is achieved, and infections will then resurge if they are eased too quickly.

Abstract

Despite various levels of preventive measures, in 2020, many countries have suffered severely from the coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Using a model, we show that population heterogeneity can affect disease-induced immunity considerably because the proportion of infected individuals in groups with the highest contact rates is greater than that in groups with low contact rates. We estimate that if R0 = 2.5 in an age-structured community with mixing rates fitted to social activity, then the disease-induced herd immunity level can be ~43%, which is substantially less than the classical herd immunity level of 60% obtained through homogeneous immunization of the population. Our estimates should be interpreted as an illustration of how population heterogeneity affects herd immunity rather than as an exact value or even a best estimate.

Philanthropy—or tax-exempt lobbying?

I pass on this piece by Brad Wible from the Editors' Choice section of the current issue of Science Magazine:

Major corporations appear to fund their charitable foundations in part to cater to politicians who are important to the firm's profitability. Integrating corporate tax returns, lobbying data, and data on U.S. congressional committee assignments, Bertrand et al. show that donations from a given corporate-funded foundation to charities in a particular congressional representative's district, or for which a congressional representative is a board member, ebb and flow according to whether the representative sits on a committee that is of interest to the corporation. The patterns parallel spending by political action committees (PACs). Around 7% of charitable giving (∼$1.2 billion annually) appears to be politically motivated, amounting to about 2.5 times the annual PAC spending and one-third of the total federal lobbying spending—and it is tax exempt and thus subsidized by taxpayers.

Am. Econ. Rev. 110, 2065 (2020).

Our default-mode network contains nine subnetworks serving different cognitive tasks.

Our brains are organized into large networks that can be identified during brain scanning. The default mode network, which has been the subject of many MindBlog posts (try the Blog's search function in the left column), engages a large number of inwardly directed cognitive functions such as mind-wandering, autobiographical and social thinking, memory, and reward. Gordon et al. now do resting-state functional connectivity studies distinguishing nine subnetworks with different specializations:

Significance

The human brain is organized into large networks. One important brain network is the Default network, which enables cognitive functions such as social thinking, memory, and reward. In group-averaged data, this network emerges as a unitary whole, despite its involvement in multiple cognitive functions. Here, we tested whether Default networks found in individual humans, rather than group-average networks, contain organized substructure. In individuals, we consistently found nine subnetworks within the Default network. These subnetworks matched brain activity patterns during cognitive tasks. Some subnetworks resembled brain circuits involved in specific Default functions. Others linked Default network to other large networks. In summary, this study describes a set of brain circuits within the Default networks of individual humans.

Abstract

The human brain is organized into large-scale networks identifiable using resting-state functional connectivity (RSFC). These functional networks correspond with broad cognitive domains; for example, the Default-mode network (DMN) is engaged during internally oriented cognition. However, functional networks may contain hierarchical substructures corresponding with more specific cognitive functions. Here, we used individual-specific precision RSFC to test whether network substructures could be identified in 10 healthy human brains. Across all subjects and networks, individualized network subdivisions were more valid—more internally homogeneous and better matching spatial patterns of task activation—than canonical networks. These measures of validity were maximized at a hierarchical scale that contained ∼83 subnetworks across the brain. At this scale, nine DMN subnetworks exhibited topographical similarity across subjects, suggesting that this approach identifies homologous neurobiological circuits across individuals. Some DMN subnetworks matched known features of brain organization corresponding with cognitive functions. Other subnetworks represented separate streams by which DMN couples with other canonical large-scale networks, including language and control networks. Together, this work provides a detailed organizational framework for studying the DMN in individual humans.

The Neurobiology of Social Distance

Bzdok and Dunbar (open source) do a definitive review of evidence that psychosocial embedding in interpersonal relationship is crucial for survival. Dunbar is well known for his demonstration of the correlation between the size of social groups and the brain size of their members, which places the natural size of groups of humans at ~150 (roughly the size of human hunter gatherer groups whose isolation has permitted them to survive into the modern era. The number of friends and family relationships we can manage at any given time is limited by our cognitive constraints to ~150). Their summary:

From babies to the elderly, psychosocial embedding in interpersonal relationships is crucial for survival.

Insufficient social stimulation affects reasoning and memory performance, hormone homeostasis, brain grey/white matter connectivity and function, as well as resilience to physical and mental disease.

Feelings of loneliness can spread through a social network, causing negatively skewed social perception, escalating morbidity and mortality, and, in older people, precipitating the onset of dementia (e.g., Alzheimer’s disease).

Placebos without deception reduce self-report and neural measures of emotional distress

Interesting work from Guevarra et al. (open source):

Several recent studies suggest that placebos administered without deception (i.e., non-deceptive placebos) can help people manage a variety of highly distressing clinical disorders and nonclinical impairments. However, whether non-deceptive placebos represent genuine psychobiological effects is unknown. Here we address this issue by demonstrating across two experiments that during a highly arousing negative picture viewing task, non-deceptive placebos reduce both a self-report and neural measure of emotional distress, the late positive potential. These results show that non-deceptive placebo effects are not merely a product of response bias. Additionally, they provide insight into the neural time course of non-deceptive placebo effects on emotional distress and the psychological mechanisms that explain how they function.

Here is a description from their text of the EEG signals measured:

The LPP is an electroencephalogram (EEG) derived event-related brain potential (ERP) response that measures millisecond changes in the neural activity involved in emotional processing. The early-time window of the LPP (400–1000 ms) indexes attention allocation34; the sustained time window (1000–6000 ms) indexes conscious appraisals and meaning-making mechanisms involved in emotion processing34,35 and is consistently downregulated by cognitive emotion regulation strategies. Consistent with its role in immediate attentional orienting responses to emotional stimuli and later appraisal processes, neural sources of the LPP include both the amygdala and dorsolateral prefrontal cortex41. Thus, the LPP is ideally suited to help examine the neural mechanisms and time course of non-deceptive placebo effects on emotional distress.

And, conditions presented to participants:

In both experiments, we randomly assigned participants to either a non-deceptive placebo group or a control group. Participants in the non-deceptive placebo group read about placebo effects and were then asked to inhale a nasal spray consisting of saline solution. They were told that the nasal spray was a placebo that contained no active ingredients, but would help reduce their negative emotional reactions to viewing distressing images if they believed it would. Participants in the control group read about the neural processes underlying the experience of pain and were also asked to inhale the same saline solution spray; however, they were told that the purpose of the nasal spray was to improve the clarity of the physiological readings we were recording in the study. The articles were matched for narrative structure, emotional content, and length

Personality dimensions are predicted by cell phone usage data

From Stachi et al.:  

Significance

Smartphones are sensor-rich computers that can easily be used to collect extensive records of behaviors, posing serious threats to individuals’ privacy. This study examines the extent to which individuals’ personality dimensions (assessed at broad domain and narrow facet levels) can be predicted from six classes of behavior: 1) communication and social behavior, 2) music consumption, 3) app usage, 4) mobility, 5) overall phone activity, and 6) day- and night-time activity, in a large sample. The cross-validated results show which Big Five personality dimensions are predictable and which specific patterns of behavior are indicative of which dimensions, revealing communication and social behavior as most predictive overall. Our results highlight the benefits and dangers posed by the widespread collection of smartphone data.

Abstract

Smartphones enjoy high adoption rates around the globe. Rarely more than an arm’s length away, these sensor-rich devices can easily be repurposed to collect rich and extensive records of their users’ behaviors (e.g., location, communication, media consumption), posing serious threats to individual privacy. Here we examine the extent to which individuals’ Big Five personality dimensions can be predicted on the basis of six different classes of behavioral information collected via sensor and log data harvested from smartphones. Taking a machine-learning approach, we predict personality at broad domain and narrow facet levels based on behavioral data collected from 624 volunteers over 30 consecutive days (25,347,089 logging events). Our cross-validated results reveal that specific patterns in behaviors in the domains of 1) communication and social behavior, 2) music consumption, 3) app usage, 4) mobility, 5) overall phone activity, and 6) day- and night-time activity are distinctively predictive of the Big Five personality traits. The accuracy of these predictions is similar to that found for predictions based on digital footprints from social media platforms and demonstrates the possibility of obtaining information about individuals’ private traits from behavioral patterns passively collected from their smartphones. Overall, our results point to both the benefits (e.g., in research settings) and dangers (e.g., privacy implications, psychological targeting) presented by the widespread collection and modeling of behavioral data obtained from smartphones.

Conversational primes influence choices - a magic trick example

From Pailhès and Kuhn:

Abstract

Past research demonstrates that unconscious primes can affect people’s decisions. However, these free choice priming paradigms present participants with very few alternatives. Magicians’ forcing techniques provide a powerful tool to investigate how natural implicit primes can unconsciously influence decisions with multiple alternatives. We used video and live performances of the mental priming force. This technique uses subtle nonverbal and verbal conversational primes to influence spectators to choose the three of diamonds. Our results show that a large number of participants chose the target card while reporting feeling free and in control of their choice. Even when they were influenced by the primes, participants typically failed to give the reason for their choice. These results show that naturally embedding primes within a person’s speech and gestures effectively influenced people’s decision making. This raises the possibility that this form of mind control could be used to effectively manipulate other mental processes.

From the text of the article:

Magic tricks provide a valuable tool to investigate psychological processes within a highly natural environment. Most magic principles rely on tightly structured action and language scripts, which allow researchers to investigate psychological processes (e.g., priming, attention, and perception) under controlled, yet realistic conditions. Forcing refers to conjuring techniques that allow magicians to covertly influence a spectator’s choice, and they provide unique tools to investigate how primes unconsciously influence people’s decisions when there is a broad range of alternatives (i.e., 52 playing cards). Many of these forces are commonly used within a magic performance context, but only a few have been empirically investigated. In this paper, we examine a forcing technique that relies on subtle conversational nonverbal and verbal primes: the mental priming force. This force was created by British illusionist Derren Brown, and uses subtle verbal and nonverbal primes to influence the spectator to think about the three of diamonds (see figure).

We recruited 90 participants (62 women) who were randomly allocated to the video or live performance groups. After watching the performance, participants were asked to write down the card they chose ...Overall, 17.8% of the participants chose the three of diamonds, 38.9% chose a three (all suits combined) and 33.3% chose a diamond (all numbers combined). The three of diamonds was the most commonly chosen card, closely followed by the three of hearts. To carry out statistical analyses, we compared these results to a condition in which participants were asked to choose a card after watching a video of the same performer and script without using any specific prime (0 out of 23 named the three of diamonds.)

Our results illustrate that the mental priming force significantly influenced participants’ choice among a large number of alternatives, and it works just as effectively when presented on video compared to when it is performed by a real person. Eighteen percent of our participants chose the target card, and most were oblivious to the force itself. Indeed, even though the force resulted in a ninefold increase chance of participants choosing the three of diamonds, participants reported that their choice was free and that they were in control of it. Investigating the way implicit cues unconsciously influence people’s thoughts provides important insights into the nature of human cognition.

The Paradoxical Role of Social Capital in the Coronavirus Pandemic

I suggest you read an insightful article by Adam Gopnik in the New Yorker with the title of this post. He begins with an interesting comparison of the King James Version of the Bible having the angels proclaiming "On earth peace, goodwill toward men" versus more militant Bibles that render the Greek phrase as "Peace on earth to men of goodwill" and asks "Is the happy news that of Heaven's dispensation of ever-increasing trust toward all people? Or is it a special favor restricted to those already possessed of good will toward us?" He goes on to examine:

...the relationship between the perniciousness of the plague and the presence or the absence of social capital in the places that suffer it. Are places that have high levels of social trust and strong institutions of civil society doing any better than those that don’t? Does good will toward men help fight the virus, or does it make no difference what the angels sing?

...the empirical results so far seem at least to suggest an intriguing paradox: that places with a great deal of social capital got hit worst by the virus, and then recovered fastest. This is reportedly the case with the secular, social-democratic countries of the European Union, none of them particularly religious, but many of them rich in shared networks of trust.

It’s a paradox of place: people who were not socially distanced at the start of the plague had an easier time learning to social-distance by its end. A striking study in Italy, for instance, found that places with high existing “civic capital” tended to “display greater mobility”—that is, people travelled around more—than places without it. But, “as soon as the threat of the virus became real, communities with high civic capital started to self-restrain and to internalize the risk of propagating the infection through social contacts.” Translated from the academese, people who are used to going out a lot stopped when people they trusted told them that doing so was a good way to get sick. That’s a process familiar to New Yorkers... We had, through nearly all of April, above a twenty-per-cent positive-testing rate; now, by living behind our masks and (mostly) staying out of bars, we have driven the number below one per cent.

In America, we have been undergoing a kind of four-year experiment in what happens to a country when social trust and social capital are not merely badly maintained but actively corroded. In Donald Trump’s government, favor flows from the head of state only to men of good will, i.e., those whom he considers to be on his side. We have been living a four-year exercise in destroying social trust and replacing it with gangster values: loyalty to the capo at all costs, and vengeance on his competitors and enemies taken at his direction.

The results are already clear. The rush to reopen in the so-called red states was motivated partly by commercial impatience but also largely by a kind of irrational rage at the “élitist” social networks that depend on the diffusion of scientific expertise. If instructed that scientific medicine is one more opinion on the spectrum of political grievance, then social distancing and mask-wearing become, like gun control, an imposition on liberty.

The disasters that have left America with far more COVID-19 deaths and a far higher per-capita infection rate than other rich countries have many causes and many lessons, acting, as they do, as an X-ray of our social inequality. But the seemingly unstoppable spread of the illness shows the cost, too, of actively looting our already diminished supply of social capital. Destroy our commonplace civilization, and the larger civilization around it will collapse, too. Where we struggle to create good will toward our fellow-citizens, illness rises and then abates. Where we encourage it only toward our kind, illness increases. It is a simple formula, though, by now, so much a matter of life and death that it would leave the angels, all of them, weeping to watch it.

Working memory capacity predicts individual differences in social-distancing compliance during the COVID-19 pandemic

Xie et al. suggest that non-compliance is associated with limitations in people's mental capacity to simultaneously retain multiple pieces of information in working memory (WM) for rational decision making that leads to social-distancing compliance.:

Significance

Before vaccination and other intervention measures become available, successful containment of an unknown infectious disease critically relies on people’s voluntary compliance with the recommended social-distancing guidelines. This involves a decision process of prioritizing the merits of social distancing over its costs, which may depend on one’s ability to compare multiple pieces of potentially conflicting information regarding social distancing in working memory. Our data support this hypothesis, highlighting the critical role of one’s working memory capacity in social-distancing compliance during the early stage of the coronavirus disease 2019 pandemic. This observation reveals a core cognitive limitation in one’s response to a public health crisis and suggests a possible cognitive venue for the development of strategies to mitigate this challenge.

Abstract

Noncompliance with social distancing during the early stage of the coronavirus disease 2019 (COVID-19) pandemic poses a great challenge to the public health system. These noncompliance behaviors partly reflect people’s concerns for the inherent costs of social distancing while discounting its public health benefits. We propose that this oversight may be associated with the limitation in one’s mental capacity to simultaneously retain multiple pieces of information in working memory (WM) for rational decision making that leads to social-distancing compliance. We tested this hypothesis in 850 United States residents during the first 2 wk following the presidential declaration of national emergency because of the COVID-19 pandemic. We found that participants’ social-distancing compliance at this initial stage could be predicted by individual differences in WM capacity, partly due to increased awareness of benefits over costs of social distancing among higher WM capacity individuals. Critically, the unique contribution of WM capacity to the individual differences in social-distancing compliance could not be explained by other psychological and socioeconomic factors (e.g., moods, personality, education, and income levels). Furthermore, the critical role of WM capacity in social-distancing compliance can be generalized to the compliance with another set of rules for social interactions, namely the fairness norm, in Western cultures. Collectively, our data reveal contributions of a core cognitive process underlying social-distancing compliance during the early stage of the COVID-19 pandemic, highlighting a potential cognitive venue for developing strategies to mitigate a public health crisis.

The coming de facto world government?

David J. Lynch does a fascinating description, which I strongly suggest that you read, of

How a little-known company kept Apple products on the market — and previewed a future less dependent on China...The little-known, Singapore-based company had to improvise when the coronavirus started spreading in China to make sure their operations didn't collapse. Its journey through the pandemic illuminates how globalization could evolve.

The main force for stability in the emerging world order may be the vast global network of buyers and suppliers that continually shifts its loci of operations as competing nation states flail about, imagining that they are running the show, while the distributed intelligence of smaller more local units of function, integrated by cloud-based systems analyzing supply and demand, is actually what matters. Lynch's article describes the remarkable ability of Singapore based Flex Ltd. (160,000 workers, 100 facilities in 30 different countries, annual revenue over $24 billion) to adapt to the sudden shut down of its China operations (50,000 workers) supplying Apple. (Flex has been making Mac Pros in an Austin TX plant since 2013 - the plant Trump claimed to have opened on a Nov. 2019 visit, proving he was bringing back high paying jobs to America.)

...as Flex’s evolution demonstrates, the pandemic did not — and likely will not — end globalization. Instead, it turbocharged trends that already were in motion when the virus first flared, including a diminishing reliance on China...Armed with data and facing a perilous world, more companies recalculated the balance between cost and resilience, between efficiency of production and certainty of delivery, and imagined a less-China-centric economy.

From a Flex command post in Milpitas, Calif., Lynn Torrel, the company’s chief procurement officer, monitors 16,000 suppliers and more than 1 million individual items using a data analytics tool called Pulse. Introduced in 2015, the cloud-based system gobbles data from 88 sources, providing a cohesive view of the multinational’s operation. Arrayed on a wall, 22 video screens provided near-real-time information on every .0005-cent screw and each integrated circuit costing hundreds of dollars...Each weekday on a 5:30 a.m. conference call, Torrel and the logistics team juggles priorities as the virus disrupts their tightly choreographed network.

The subsequent text describes the amazing flexibility and resilience of Flex's response to constantly shifting patterns of travel restrictions and country specific shutdowns and openings.

Conserved aspects of sex-biased brain development in humans and mice

It is a pity that in our current political environment any scientist adding to the abundant evidence of brain differences between the sexes runs the risk of being "cancelled" as an unredeemable sexist by the "woke" intelligentsia. Mostly, however, work of the sort described by Liu et al. remains under or outside of their radar, and is consumed only by fellow scientists and the scientifically literate. I pass on their summary statements, and here is a link to a neat movie showing their data, which is also downloadable as an mp3 file. The caption to the video: "Movie of continuous coronal slices shows overlapping significant sex differences in human GMV (gray matter volume) - with male larger than female shown as cyan, and female greater than male shown as yellow.)

Significance

Sex differences in brain organization are theoretically important for our understanding of sex differences in human cognition and behavior. However, neurobiological sex differences have been easier to characterize in mice than in humans. Recent murine work has revealed a highly reproducible spatial patterning of gray matter volume (GMV) sex differences that is centered on systems for socioreproductive behavior and correlated with regional expression of sex chromosome genes. We integrate neuroimaging and transcriptomic data to establish that these same characteristics also apply to GMV sex differences in humans. These findings establish conserved aspects of sex-biased brain development in humans and mice, and update our understanding of the consistency, candidate causes, and potential functional corollaries of sex-biased brain anatomy in humans.

Abstract

Humans display reproducible sex differences in cognition and behavior, which may partly reflect intrinsic sex differences in regional brain organization. However, the consistency, causes and consequences of sex differences in the human brain are poorly characterized and hotly debated. In contrast, recent studies in mice—a major model organism for studying neurobiological sex differences—have established: 1) highly consistent sex biases in regional gray matter volume (GMV) involving the cortex and classical subcortical foci, 2) a preponderance of regional GMV sex differences in brain circuits for social and reproductive behavior, and 3) a spatial coupling between regional GMV sex biases and brain expression of sex chromosome genes in adulthood. Here, we directly test translatability of rodent findings to humans. First, using two independent structural-neuroimaging datasets (n > 2,000), we find that the spatial map of sex-biased GMV in humans is highly reproducible (r > 0.8 within and across cohorts). Relative GMV is female biased in prefrontal and superior parietal cortices, and male biased in ventral occipitotemporal, and distributed subcortical regions. Second, through systematic comparison with functional neuroimaging meta-analyses, we establish a statistically significant concentration of human GMV sex differences within brain regions that subserve face processing. Finally, by imaging-transcriptomic analyses, we show that GMV sex differences in human adulthood are specifically and significantly coupled to regional expression of sex-chromosome (vs. autosomal) genes and enriched for distinct cell-type signatures. These findings establish conserved aspects of sex-biased brain development in humans and mice, and shed light on the consistency, candidate causes, and potential functional corollaries of sex-biased brain anatomy in humans.

Cats associated with early human farming long before their domestication

As the herd of Abyssinian cats in my has grown, now numbering two 12 year olds and two kittens, I've become more curious about the origins of this breed and of domestic cats in general. It turn out, as shown in recent work by Jrahcarz et al., that cats were predators feeding on rodents in grain stores in Neolithic farming settlements for at least a thousand years before their domestication as house cats.

Most of today’s domesticates began as farm animals, but cat domestication took a different path. Cats became commensal of humans somewhere in the Fertile Crescent, attracted to early farmers’ settlements by rodent pests. Cat remains from Poland dated to 4,200 to 2,300 y BCE are currently the earliest evidence for the migration of the Near Eastern wildcat to Central Europe. Tracking the possible synanthropic origin of that migration, we used stable isotopes to investigate the paleodiet. We found that the ecological balance was already changed due to the expansion of Neolithic farmlands. We conclude that among the Late Neolithic Near Eastern wildcats from Poland were free-living individuals, who preyed on rodent pests and shared ecological niches with native European wildcats.

As regards the origins of my Abyssianians, I have always passed on the story that all of the current registered purebreds derive from a male brought to England by a British solider in the late 19th century. A quick google look, however, shows their origins to be far from clear.

Robust evidence for bisexual orientation among men

It is interesting that debate over whether genuinely bisexual men actually exist has continued for so long. In the current issue of PNAS Jabbour et al. appear to settle the issue:  

Significance

There has long been skepticism among both scientists and laypersons that male bisexual orientation exists. Skeptics have claimed that men who self-identify as bisexual are actually homosexual or heterosexual. (The existence of female bisexuality has been less controversial.) This controversy can be resolved using objective, genital responses of men to male and female erotic stimuli. We combined nearly all available data (from eight previous American, British, and Canadian studies) to form a dataset of more than 500 men, much larger than any previous individual study, and conducted rigorous statistical tests. Results provided compelling evidence that bisexual-identified men tend to show bisexual genital and subjective arousal patterns. Male sexual orientation is expressed on a continuum rather than dichotomously.

Abstract

The question whether some men have a bisexual orientation—that is, whether they are substantially sexually aroused and attracted to both sexes—has remained controversial among both scientists and laypersons. Skeptics believe that male sexual orientation can only be homosexual or heterosexual, and that bisexual identification reflects nonsexual concerns, such as a desire to deemphasize homosexuality. Although most bisexual-identified men report that they are attracted to both men and women, self-report data cannot refute these claims. Patterns of physiological (genital) arousal to male and female erotic stimuli can provide compelling evidence for male sexual orientation. (In contrast, most women provide similar physiological responses to male and female stimuli.) We investigated whether men who self-report bisexual feelings tend to produce bisexual arousal patterns. Prior studies of this issue have been small, used potentially invalid statistical tests, and produced inconsistent findings. We combined nearly all previously published data (from eight previous studies in the United States, United Kingdom, and Canada), yielding a sample of 474 to 588 men (depending on analysis). All participants were cisgender males. Highly robust results showed that bisexual-identified men’s genital and subjective arousal patterns were more bisexual than were those who identified as exclusively heterosexual or homosexual. These findings support the view that male sexual orientation contains a range, from heterosexuality, to bisexuality, to homosexuality.

Inflammaging and COVID-19

I pass on the first paragraph from a Science Perspectives article by Akbar and Gilroy, and suggest that you have a look at the whole article.

Aging is associated with increased morbidity arising from a range of tissue dysfunctions. A common denominator of age-associated frailty is increased baseline inflammation, called inflammaging, that is present in older individuals. Recent studies have shown that the presence of excessive inflammation can inhibit immunity in both animals and humans and that this can be prevented by blocking inflammatory processes. This finding has important implications for the immunity of older individuals who are infected with pathogens such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that induce overwhelming inflammation, which can be fatal, particularly in older people. Reducing inflammation may be a therapeutic strategy for enhancing immunity in older people.

Stepping backwards enhances cognitive control.

From Koch et al., some interesting work on the role of body locomotion in the recruitment of control processes.:

In the most fundamental and literal sense, approach refers to decreasing, and avoidance to increasing, the physical distance between the self and the outside world. In our view, body locomotion most purely taps into this fundamental nature of approach and avoidance. In everyday life, individuals typically approach desired stimuli by stepping forward and avoid aversive stimuli by stepping backward

...The idea that body locomotion may trigger approach and avoidance orientations has, so far, not been tested...we expected that stepping backward would increase the recruitment of cognitive control relative to stepping forward. To test this prediction, we gauged cognitive functioning by means of a Stroop task immediately after a participant stepped in one direction. The Stroop task requires naming the color in which stimulus words are printed while ignoring their semantic meaning, which is actually processed more automatically than the color. Cognitive control is required to override the tendency to respond to the semantic meaning and instead respond to the color.

...our study showed that stepping backward significantly enhanced cognitive performance compared to stepping forward or sideways. Considering the effect size, backward locomotion appears to be a very powerful trigger to mobilize cognitive resources. Thus, whenever you encounter a difficult situation, stepping backward may boost your capability to deal with it effectively.