How human breeding has changed dogs’ brains

Hecht et al. have identified brain networks in dogs related to behavioral specializations roughly corresponding to sight hunting, scent hunting, guarding, and companionship. Here is their detailed abstract:

Humans have bred different lineages of domestic dogs for different tasks such as hunting, herding, guarding, or companionship. These behavioral differences must be the result of underlying neural differences, but surprisingly, this topic has gone largely unexplored. The current study examined whether and how selective breeding by humans has altered the gross organization of the brain in dogs. We assessed regional volumetric variation in MRI studies of 62 male and female dogs of 33 breeds. Neuroanatomical variation is plainly visible across breeds. This variation is distributed nonrandomly across the brain. A whole-brain, data-driven independent components analysis established that specific regional subnetworks covary significantly with each other. Variation in these networks is not simply the result of variation in total brain size, total body size, or skull shape. Furthermore, the anatomy of these networks correlates significantly with different behavioral specialization(s) such as sight hunting, scent hunting, guarding, and companionship. Importantly, a phylogenetic analysis revealed that most change has occurred in the terminal branches of the dog phylogenetic tree, indicating strong, recent selection in individual breeds. Together, these results establish that brain anatomy varies significantly in dogs, likely due to human-applied selection for behavior.

A triple drug combination increases lifespan by 48%

In Drosophila flies, to be sure, but the nutrient sensing pathways that are the target of the drugs are common to all animals. Here is the abstract from open source article by Castillo-!uan et al.:

Increasing life expectancy is causing the prevalence of age-related diseases to rise, and there is an urgent need for new strategies to improve health at older ages. Reduced activity of insulin/insulin-like growth factor signaling (IIS) and mechanistic target of rapamycin (mTOR) nutrient-sensing signaling network can extend lifespan and improve health during aging in diverse organisms. However, the extensive feedback in this network and adverse side effects of inhibition imply that simultaneous targeting of specific effectors in the network may most effectively combat the effects of aging. We show that the mitogen-activated protein kinase kinase (MEK) inhibitor trametinib, the mTOR complex 1 (mTORC1) inhibitor rapamycin, and the glycogen synthase kinase-3 (GSK-3) inhibitor lithium act additively to increase longevity in Drosophila. Remarkably, the triple drug combination increased lifespan by 48%. Furthermore, the combination of lithium with rapamycin cancelled the latter’s effects on lipid metabolism. In conclusion, a polypharmacology approach of combining established, prolongevity drug inhibitors of specific nodes may be the most effective way to target the nutrient-sensing network to improve late-life health.

Skill development - the intelligence vs. practice debate reframed

Vaci et al. note that what is often overlooked in the nature vs. nurture debate is the fact that both factors interact with each other:

The relative importance of different factors in the development of human skills has been extensively discussed. Research on expertise indicates that focused practice may be the sole determinant of skill, while intelligence researchers underline the relative importance of abilities at even the highest level of skill. There is indeed a large body of research that acknowledges the role of both factors in skill development and retention. It is, however, unknown how intelligence and practice come together to enable the acquisition and retention of complex skills across the life span. Instead of focusing on the 2 factors, intelligence and practice, in isolation, here we look at their interplay throughout development. In a longitudinal study that tracked chess players throughout their careers, we show that both intelligence and practice positively affect the acquisition and retention of chess skill. Importantly, the nonlinear interaction between the 2 factors revealed that more intelligent individuals benefited more from practice. With the same amount of practice, they acquired chess skill more quickly than less intelligent players, reached a higher peak performance, and arrested decline in older age. Our research demonstrates the futility of scrutinizing the relative importance of highly intertwined factors in human development.

The miracle cure - just move

A summary from the editor of the British Medical Journal of work by Ekelund et. al.:

As miracle cures are hard to come by, any claims that a treatment is 100% safe and effective must always be viewed with intense scepticism. There is perhaps one exception. Physical activity has been called a miracle cure by no less a body than the Academy of Medical Sciences (http://bit.ly/2lTqDvc); and, like those who avail themselves of it, the supporting science grows stronger by the day. The BMJ recently published a systematic review showing a clear dose-response relation between physical activity and all cause mortality (doi:10.1136/bmj.l4570). The authors concluded that any level of activity is better than none, and more is better still, a message recently encapsulated in the updated guidelines from the UK’s chief medical officers (doi:10.1136/bmj.l5470).

The statement from the authors on their analysis of numerous studies:

We conducted a harmonised meta-analysis to examine the association between accelerometer measured physical activity and sedentary time and all cause mortality. Specifically, we examined the dose-response relations of total physical activity, different intensities of physical activity (light, low light, high light, moderate to vigorous, and vigorous) and sedentary time and all cause mortality.

Feeling grateful - a shortcut to virtuous behavior.

Psychologist David DeSteno, in an Aeon essay, summarizes his experiments suggesting that moving towards a more virtuous life might accomplished by simply cultivating gratitude, a more simple route than through deep deliberation on noble qualities such as honesty and generosity. Subjects were asked to report the results of a coin toss in which heads yielded a larger financial reward than tails. The coins were rigged to always come up tails.

The percentage of cheaters fell by half (from almost 49 per cent to 27 per cent) among those who had just recalled a time when they felt grateful, compared with those who described a time when they felt happy or no particular emotion at all.

They then did a second experiment that..

...had two key differences. First, the coin flip determined whether any given participant would have to complete an enjoyable 10-minute task or a difficult 45-minute one. Second, we led participants to believe that the next person to come would be assigned to complete whichever task remained.

In deciding to cheat by reporting that the virtual coin flip came up heads, people were giving themselves a much shorter and more enjoyable task, but in so doing, were also unfairly dooming another person to a more onerous task.

As one might imagine, the overall frequency of cheating was lower. Nonetheless, gratitude worked in the exact same way. Whereas 17 per cent of people cheated when feeling neutral or happy, only 2 per cent cheated when feeling grateful.

The empirical literature shows a similar influence of gratitude on other virtues. People feeling grateful are more likely to help others who request assistance, to divide their profits in a more egalitarian way, to be loyal even at cost to themselves, to be less materialistic, and even to exercise as opposed to loafing.

Five myths about aging.

I want to pass on a few clips from this piece by William Mair, who researches the biology of aging at Harvard:

MYTH NO. 1 Biological aging can't be slowed. The growing field of geroscience offers hope... that genetic alterations and drugs such as rapamycin can slow the rate at which animals age.

MYTH NO. 2 Live fast, die young. Recent work shows that regular exercise helps slow key signs of aging, boosting immune function and curbing mental decline. If anything, conserving our batteries as isolated couch potatoes ages us faster.

MYTH NO. 3 Antioxidants slow aging. Free radicals...have captured the public imagination as a source of old age with little scientific evidence. There is in fact more negative data than positive examples.

MYTH NO. 4 Fewer calories mean a longer life. In truth, we just don’t know that the benefit of strict diets lies solely in their calorie content. Increasingly, it seems that many of the positive effects of calorie restriction on aging may be unrelated to caloric intake. Hungry animals and people tend to eat faster, and as a result spend more of their day eating nothing. These extended periods of abstinence are enough to slow aging in mice, whether overall calorie intake is reduced or not. The science uncoupling the effects of fasting and calorie restriction on aging is in its infancy.

MYTH NO. 5 Short telomeres explain aging. Aging is not caused by one event, however, as compelling as fraying telomeres may be. Some of our cells do not divide at all, and they age without shortened telomeres. Many animals have telomeres much longer than ours, yet they age faster than we do. Shortening telomeres may even be useful, protecting against unchecked cell division, which is a hallmark of cancer.

The Metamorphosis of the Western Soul

I want to point to an article by Will Storr "The Metamorphosis of the Western Soul" that has been languishing for over a year in my list of references that might become the basis of a MindBlog post. Storr presents a nice distillation of the story of how Between 1965 and 1985, the Western self was transformed. Storr's basic point is that economic forces are the dominant reason for these changes.

We turned from anti-materialistic, stick-it-to-the-Man hippies into greed-is-good yuppies... While the origins of such changes cannot be reduced to a single source, I believe we can point to a dominant one: the economy. In the early 1980s, President Ronald Reagan and the British Prime Minister Margaret Thatcher rewrote the rules by which we had once lived. And that, with stunning rapidity, changed who we were.

Storr proceeds review the historical story of how citizens of the individualistic West and the collectivist East have developed fundamental cognitive differences - largely adaptations to different physical landscapes - in how they view the world through collectivist versus individualistic filters. But, there is plasticity:

Humans are born incomplete. The brain absorbs huge amounts of essential information throughout childhood and adolescence, which it uses to carry on building who we are. It’s as if the brain asks a single, vital question: Who do I have to be, in this place, to thrive? If it was a boastful hustler in ancient Greece and a humble team-player in ancient China, then who is it in the West today?

The answer is a neoliberal...After the economic chaos of the 1970s, it was decided that the United States and Britain had become too collective. Previous decades had seen the introduction of the New Deal, which included the Social Security Act, strict regulations on banking and business, and the rising power of the unions. This collectively tilted economy sired a collectively tilted people...For Mr. Reagan and Mrs. Thatcher, saving ourselves meant rediscovering our individualist roots.

They cut taxes and regulations; they battled unions; they shrunk the welfare state; they privatized assets and weakened the state’s safety nets. They pursued the neoliberal dream of globalization — one free market that covered the earth. As much of human life as possible was to become a competition of self versus self...In 1981, Margaret Thatcher said “Economics are the method: The object is to change the soul.” And that’s precisely what happened.

Before 2008, it felt as if neoliberalism was basically working for most people. But since the crash, millions have come to see the system as broken...We have seen the neoliberal Hillary Clinton falter and the antiglobalist Donald Trump triumph. Britain’s Brexit was secured by antiglobalist arguments....The perception of a broken, rigged economy has left us angry and increasingly tribal, which might explain this recent trend toward “us” over the narcissistic “me.”

If this is correct, it’s yet more evidence that who we are is powerfully influenced by where we are. Humans want to get along and get ahead and will become whoever they need to be in order to do so. In the 21st century, those rules are no longer set by our physical landscape. Today, the deep and enormously powerful controlling force is the economy.

Shape of your heart is determined by whether you run or sit.

Shave et al. show that endurance runners and farmers have larger, elongated left ventricles with thin walls (traits that help pump large volumes of blood for a long time) compared with football linemen, whose training emphasizes short, high-intensity exercise. Linemen, as well has sedentary people, have shorter, wider ventricles with thicker walls and are more prone to hypertensive heart disease. Their experiments used ultrasound imaging to examine the hearts of more than 160 adult men from four groups: long-distance runners, sedentary adults, highly trained football linemen, and the Tarahumara, Native American farmers renowned for their running ability.

Abstract

Chimpanzees and gorillas, when not inactive, engage primarily in short bursts of resistance physical activity (RPA), such as climbing and fighting, that creates pressure stress on the cardiovascular system. In contrast, to initially hunt and gather and later to farm, it is thought that preindustrial human survival was dependent on lifelong moderate-intensity endurance physical activity (EPA), which creates a cardiovascular volume stress. Although derived musculoskeletal and thermoregulatory adaptations for EPA in humans have been documented, it is unknown if selection acted similarly on the heart. To test this hypothesis, we compared left ventricular (LV) structure and function across semiwild sanctuary chimpanzees, gorillas, and a sample of humans exposed to markedly different physical activity patterns. We show the human LV possesses derived features that help augment cardiac output (CO) thereby enabling EPA. However, the human LV also demonstrates phenotypic plasticity and, hence, variability, across a wide range of habitual physical activity. We show that the human LV’s propensity to remodel differentially in response to chronic pressure or volume stimuli associated with intense RPA and EPA as well as physical inactivity represents an evolutionary trade-off with potential implications for contemporary cardiovascular health. Specifically, the human LV trades off pressure adaptations for volume capabilities and converges on a chimpanzee-like phenotype in response to physical inactivity or sustained pressure loading. Consequently, the derived LV and lifelong low blood pressure (BP) appear to be partly sustained by regular moderate-intensity EPA whose decline in postindustrial societies likely contributes to the modern epidemic of hypertensive heart disease.

The default mode network represents esthetic appeal.

Vessel et al. note another role for the default mode network of our brain:

Significance

Despite being highly subjective, aesthetic experiences are powerful moments of interaction with one’s surroundings, shaping behavior, mood, beliefs, and even a sense of self. The default-mode network (DMN), which sits atop the cortical hierarchy and has been implicated in self-referential processing, is typically suppressed when a person engages with the external environment. Yet not only is the DMN surprisingly engaged when one finds a visual artwork aesthetically moving, here we present evidence that the DMN also represents aesthetic appeal in a manner that generalizes across visual aesthetic domains, such as artworks, landscapes, or architecture. This stands in contrast to ventral occipitotemporal cortex (VOT), which represents the content of what we see, but does not contain domain-general information about aesthetic appeal.

Abstract

Visual aesthetic evaluations, which impact decision-making and well-being, recruit the ventral visual pathway, subcortical reward circuitry, and parts of the medial prefrontal cortex overlapping with the default-mode network (DMN). However, it is unknown whether these networks represent aesthetic appeal in a domain-general fashion, independent of domain-specific representations of stimulus content (artworks versus architecture or natural landscapes). Using a classification approach, we tested whether the DMN or ventral occipitotemporal cortex (VOT) contains a domain-general representation of aesthetic appeal. Classifiers were trained on multivoxel functional MRI response patterns collected while observers made aesthetic judgments about images from one aesthetic domain. Classifier performance (high vs. low aesthetic appeal) was then tested on response patterns from held-out trials from the same domain to derive a measure of domain-specific coding, or from a different domain to derive a measure of domain-general coding. Activity patterns in category-selective VOT contained a degree of domain-specific information about aesthetic appeal, but did not generalize across domains. Activity patterns from the DMN, however, were predictive of aesthetic appeal across domains. Importantly, the ability to predict aesthetic appeal varied systematically; predictions were better for observers who gave more extreme ratings to images subsequently labeled as “high” or “low.” These findings support a model of aesthetic appreciation whereby domain-specific representations of the content of visual experiences in VOT feed in to a “core” domain-general representation of visual aesthetic appeal in the DMN. Whole-brain “searchlight” analyses identified additional prefrontal regions containing information relevant for appreciation of cultural artifacts (artwork and architecture) but not landscapes.

Cross-national negativity bias in reacting to news

There seems to be a world-wide anxiety industry of media that find maximum profits in presenting mostly negative news - in a way similar to the drug companies that have reaped great profits from flooding distressed population areas with opioids. An interesting study in this area comes from Soroka et al., who provide more information on our human tendency to react more strongly to negative than positive information. (See also my post on Pinker's "Enlightenment Now" book that engages this topic):

What accounts for the prevalence of negative news content? One answer may lie in the tendency for humans to react more strongly to negative than positive information. “Negativity biases” in human cognition and behavior are well documented, but existing research is based on small Anglo-American samples and stimuli that are only tangentially related to our political world. This work accordingly reports results from a 17-country, 6-continent experimental study examining psychophysiological reactions to real video news content. Results offer the most comprehensive cross-national demonstration of negativity biases to date, but they also serve to highlight considerable individual-level variation in responsiveness to news content. Insofar as our results make clear the pervasiveness of negativity biases on average, they help account for the tendency for audience-seeking news around the world to be predominantly negative. Insofar as our results highlight individual-level variation, however, they highlight the potential for more positive content, and suggest that there may be reason to reconsider the conventional journalistic wisdom that “if it bleeds, it leads.”

An update on the science of ‘free will’

I want to point to an excellent article by Gholilpour in the Atlantic Magazine that describes a reinterpretation of experiments by Libet taken to suggest that our brains 'decide' to initiate a movement before our subjective awareness of intending to initiate that movement. A 'readiness potential' is observed about 500 msec before an action occurs, while a subject reports initiating that action about 150 msec before it occurs. Gholilpour points to work of Schurger and colleagues that suggests that the readiness potential is not the mark of a brain's brewing intention, but something much more circumstantial.

...Schurger and his colleagues ... proposed an explanation. Neuroscientists know that for people to make any type of decision, our neurons need to gather evidence for each option. The decision is reached when one group of neurons accumulates evidence past a certain threshold. Sometimes, this evidence comes from sensory information from the outside world: If you’re watching snow fall, your brain will weigh the number of falling snowflakes against the few caught in the wind, and quickly settle on the fact that the snow is moving downward.

Libet’s experiment, Schurger pointed out, provided its subjects with no such external cues. To decide when to tap their fingers, the participants simply acted whenever the moment struck them. Those spontaneous moments, Schurger reasoned, must have coincided with the haphazard ebb and flow of the participants’ brain activity. They would have been more likely to tap their fingers when their motor system happened to be closer to a threshold for movement initiation.

This would not imply, as Libet had thought, that people’s brains “decide” to move their fingers before they know it. Hardly. Rather, it would mean that the noisy activity in people’s brains sometimes happens to tip the scale if there’s nothing else to base a choice on, saving us from endless indecision when faced with an arbitrary task. The readiness potential would be the rising part of the brain fluctuations that tend to coincide with the decisions. This is a highly specific situation, not a general case for all, or even many, choices.

The name Schurger rang a bell with me, and so I did a MindBlog search, only to discover that I had reported Schurger's work in a 2016 post "A 50 year misunderstanding of how we decide to initiate action - our intuition is valid". I then proceeded to completely forget about it when I was preparing a subsequent 2019 lecture mentioning Libet's work. The conventional dogma that we are 'late to action' was apparently burned into my brain - most embarrassing. (I've now inserted the new perspective into four of my web lectures, dating as far back as 2012). The real clincher is...

In a new study under review for publication in the Proceedings of the National Academy of Sciences, Schurger and two Princeton researchers repeated a version of Libet’s experiment. To avoid unintentionally cherry-picking brain noise, they included a control condition in which people didn’t move at all. An artificial-intelligence classifier allowed them to find at what point brain activity in the two conditions diverged. If Libet was right, that should have happened at 500 milliseconds before the movement. But the algorithm couldn’t tell any difference until about only 150 milliseconds before the movement, the time people reported making decisions in Libet’s original experiment.

In other words, people’s subjective experience of a decision—what Libet’s study seemed to suggest was just an illusion—appeared to match the actual moment their brains showed them making a decision.

Gholilpour points out that this does not resolve the question of free will, it only deepens the question, which is the subject of an intensive collaboration between neuroscientists and philosophers, backed by $7 million from two private foundations, the John Templeton Foundation and the Fetzer Institute.

More critique of work linking loving kindness meditation and cellular again

In my Sept. 23 post, "Loving kindness meditation slows cellular aging?", I gave a few of the reasons that the article triggered my bullshit detector. A email from Harris Friedman, Univ. of Florida, has pointed me to their more extended critique in a letter to the editor of Psychoneuroendocrinology, which I pass on in a slightly truncated version:

Extraordinary claims require compelling evidence: Concerns about “loving-kindness meditation slows biological aging in novices”

The recent paper by Le Nguyen et al. (2019) makes the extra- ordinary claim that loving-kindness meditation (LKM) slows biological aging. Unfortunately, its headline-grabbing title lacks compelling evidence. This paper shows telomere length (TL) decreased considerably in a control group over a very short time period, as compared to a LKM group, while a mindfulness meditation (MM) group was somewhere in between. From this difference, the paper argues that LKM slows biological aging, which is quite a logical leap. Clearly LKM had nothing to do with the extent of TL shrinkage in the control group, and why the control group’s TL decreased so much is ignored in the paper. More generally, there are many problems with using TL as a proxy for biological aging. Even if this paper’s basic logic is accepted, there are many problems with how the paper’s data are handled.1 The most important problem is the absence of any analyses that provides a direct and straightforward examination of pre-post TL as a function of experimental condition. Consequently, we ran a 2×3 mixed factorial ANOVA using TL measured across two times (pre and post) compared across three conditions (control, MM, and LKM) with the paper’s data. Although a significant repeated measures main effect was found, the interaction with experimental condition was non-sig- nificant. One-way ANOVAs examining pre-, post-, and change/differ- ence TL variables as a function of condition also produced non-sig nificant results. Looking at the data using other statistical approaches, however, did show some pattern of mixed results that trend, although most are non-significant, in the direction of the LKM group having less TL shortening compared to the other groups. Regardless of analysis, effect sizes were consistently meager.

In addition, there are several serious confounds compromising any valid comparison among the groups. For example, the data show that six in the control group engaged in some meditation, and one even reported meditating 16 days during the study’s short time-span. This hardly constitutes an adequate control group for a meditation study. Also, the LKM group spent considerably more time meditating than the MM group, so these did not differ only in meditation type. We are unable to address many other problems with this paper due to this journal’s length restrictions in a letter to the editor. We simply conclude that this paper’s extraordinary claim does not have the compelling evidence to back it up, and we urge not making extraordinary claims without such evidence. 

Harris L. Friedman - University of Florida, United States
Douglas A. MacDonald - University of Detroit Mercy, United States
Nicholas J.L. Brown-  University of Groningen, the Netherlands
James C. Coyne University of Pennsylvania, United States

Psilocybin + Mindfulness Meditation change brain connectivity - lasting positive effects

Dolan points to work by Smigielski et al.:

Both psychedelics and meditation exert profound modulatory effects on consciousness, perception and cognition, but their combined, possibly synergistic effects on neurobiology are unknown. Accordingly, we conducted a randomized, double-blind, placebo-controlled study with 38 participants following a single administration of the psychedelic psilocybin (315 μg/kg p.o.) during a 5-day mindfulness retreat. Brain dynamics were quantified directly pre- and post-intervention by functional magnetic resonance imaging during the resting state and two meditation forms. The analysis of functional connectivity identified psilocybin-related and mental state–dependent alterations in self-referential processing regions of the default mode network (DMN). Notably, decoupling of medial prefrontal and posterior cingulate cortices, which is thought to mediate sense of self, was associated with the subjective ego dissolution effect during the psilocybin-assisted mindfulness session. The extent of ego dissolution and brain connectivity predicted positive changes in psycho-social functioning of participants 4 months later. Psilocybin, combined with meditation, facilitated neurodynamic modulations in self-referential networks, subserving the process of meditation by acting along the anterior–posterior DMN connection. The study highlights the link between altered self-experience and subsequent behavioral changes. Understanding how interventions facilitate transformative experiences may open novel therapeutic perspectives. Insights into the biology of discrete mental states foster our understanding of non-ordinary forms of human self-consciousness and their concomitant brain substrate.

Mindfulness doesn't reduce impulsive behavior.

Korponay, Davidson and colleagues present results of a study that were contrary to their expectation that the practice of mindfulness meditation would correlate with a reduction in impulsive behaviors (like having that second dish of ice cream). What they found is that neither short-term nor long-term meditation appears to be effective for reducing impulsivity that is not related to attentional difficulties, but rather is a function of motor control and planning capacities. Here is their detailed abstract:

Interest has grown in using mindfulness meditation to treat conditions featuring excessive impulsivity. However, while prior studies find that mindfulness practice can improve attention, it remains unclear whether it improves other cognitive faculties whose deficiency can contribute to impulsivity. Here, an eight-week mindfulness intervention did not reduce impulsivity on the go/no-go task or Barratt Impulsiveness Scale (BIS-11), nor produce changes in neural correlates of impulsivity (i.e. frontostriatal gray matter, functional connectivity, and dopamine levels) compared to active or wait-list control groups. Separately, long-term meditators (LTMs) did not perform differently than meditation-naïve participants (MNPs) on the go/no-go task. However, LTMs self-reported lower attentional impulsivity, but higher motor and non-planning impulsivity on the BIS-11 than MNPs. LTMs had less striatal gray matter, greater cortico-striatal-thalamic functional connectivity, and lower spontaneous eye-blink rate (a physiological dopamine indicator) than MNPs. LTM total lifetime practice hours (TLPH) did not signifcantly relate to impulsivity or neurobiological metrics. Findings suggest that neither short nor long-term mindfulness practice may be efective for redressing impulsive behavior derived from inhibitory motor control or planning capacity defcits in healthy adults. Given the absence of TLPH relationships to impulsivity or neurobiological metrics, diferences between LTMs and MNPs may be attributable to pre-existing diferences.

Gender and race stereotypes - what's in a name...

Eaton et al. give us more data on the application of gender and race stereotypes in academia:

The current study examines how intersecting stereotypes about gender and race influence faculty perceptions of post-doctoral candidates in STEM fields in the United States. Using a fully-crossed, between-subjects experimental design, biology and physics professors (n = 251) from eight large, public, U.S. research universities were asked to read one of eight identical curriculum vitae (CVs) depicting a hypothetical doctoral graduate applying for a post-doctoral position in their field, and rate them for competence, hireability, and likeability. The candidate’s name on the CV was used to manipulate race (Asian, Black, Latinx, and White) and gender (female or male), with all other aspects of the CV held constant across conditions. Faculty in physics exhibited a gender bias favoring the male candidates as more competent and more hirable than the otherwise identical female candidates. Further, physics faculty rated Asian and White candidates as more competent and hirable than Black and Latinx candidates, while those in biology rated Asian candidates as more competent and hirable than Black candidates, and as more hireable than Latinx candidates. An interaction between candidate gender and race emerged for those in physics, whereby Black women and Latinx women and men candidates were rated the lowest in hireability compared to all others. Women were rated more likeable than men candidates across departments. Our results highlight how understanding the underrepresentation of women and racial minorities in STEM requires examining both racial and gender biases as well as how they intersect.

Cognitive and Affective Neuroscience

I want to point the subset of MindBlog readers interested in brain-behavior correlations to the journal “Social Cognitive and Affective Neuroscience,” particularly to the June 2019 issue. Most of the articles in this issue are open source, and a scan of the article abstracts gives a good sense of the kind of work being done in this field to identify correlations between behaviors and brain activities in different brain areas. Such work gives us an idea of where to focus our attention when extreme behaviors are at issue, such as (in the first article) being willing to fight and die for a cause. Another interesting article suggests that the medial prefrontal cortex may play a role in maintaining a positively biased self-concept.

People of color - getting quantitative about police-involved deaths

From Edwards et al.:

Significance

Police violence is a leading cause of death for young men in the United States. Over the life course, about 1 in every 1,000 black men can expect to be killed by police. Risk of being killed by police peaks between the ages of 20 y and 35 y for men and women and for all racial and ethnic groups. Black women and men and American Indian and Alaska Native women and men are significantly more likely than white women and men to be killed by police. Latino men are also more likely to be killed by police than are white men.

Abstract

We use data on police-involved deaths to estimate how the risk of being killed by police use of force in the United States varies across social groups. We estimate the lifetime and age-specific risks of being killed by police by race and sex. We also provide estimates of the proportion of all deaths accounted for by police use of force. We find that African American men and women, American Indian/Alaska Native men and women, and Latino men face higher lifetime risk of being killed by police than do their white peers. We find that Latina women and Asian/Pacific Islander men and women face lower risk of being killed by police than do their white peers. Risk is highest for black men, who (at current levels of risk) face about a 1 in 1,000 chance of being killed by police over the life course. The average lifetime odds of being killed by police are about 1 in 2,000 for men and about 1 in 33,000 for women. Risk peaks between the ages of 20 y and 35 y for all groups. For young men of color, police use of force is among the leading causes of death.

Red and Blue Voters Live in Different Economies

Wow... if you want some graphics that powerfully describe our current political malaise, check out Edsall's Op-Ed piece in the NYTimes. Here is a graph showing how economic output and income for Democratic and Republican House districts diverged over the last decade - two different economies that are diverging rapidly:

Another Edsall piece notes that insecurity caused by rapid cultural change as well as economic insecurity has generated a class of voters who feel powerless and angry, and actually feel a need for the chaos Trump generates - that they hope might disrupt the system that disadvantages them.

Mindfulness training and attentional control of mind-wandering

Several studies have suggested that mindfulness training can strengthen the connections between the networks in our dorsolateral prefrontal cortex [DLPFC] attentional executive control network and those supporting the posterior cingulate cortex [PCC] default mode network active in mind-wandering. Davidson and his colleagues have expanded on this to see whether a Mindfulness-Based Stress Reduction (MBSR) course can increase DLPFC-PCC connectivity:

Mindfulness meditation training has been shown to increase resting state functional connectivity between nodes of the frontoparietal executive control network (dorsolateral prefrontal cortex [DLPFC]) and the default mode network (posterior cingulate cortex [PCC]). We investigated whether these effects generalized to a Mindfulness-Based Stress Reduction (MBSR) course, and tested for structural and behaviorally relevant consequences of change in connectivity. Healthy, meditationnaïve adults were randomized to either MBSR (N=48), an active (N=47) or waitlist (N=45) control group. Participants completed behavioral testing, resting state fMRI scans, and diffusion tensor scans at pre-randomization (T1), post-intervention (T2) and approximately 5.5 months later (T3). We found increased T2-T1 PCC–DLPFC resting connectivity for MBSR relative to control groups. Although these effects did not persist through long-term follow-up (T3-T1), MBSR participants showed a significantly stronger relationship between days of practice (T1 to T3) and increased PCC–DLPFC resting connectivity than participants in the active control group. Increased PCC–DLPFC resting connectivity in MBSR participants was associated with increased microstructural connectivity of a white matter tract connecting these regions, and increased self reported attention. These data show that MBSR increases PCC–DLPFC resting connectivity, which is related to increased practice time, attention, and structural connectivity.

Loving kindness meditation slows cellular aging?

I like to be generous, loving, kind and nice, but a recent PsyPost article on the slowing of cellular aging by loving-kindness meditation triggered my bullshit detector. I first pass on the summary and abstract of the work referenced in the article by Le Nguyen et al., and then get a bit into the details available only to those who have journal access (motivated readers can request a PDF of the article from me). It is a noble and complicated effort, with proper double blind controls, but with statistics compromised by a small sample size and measured changes in DNA telomere length (a proxy for aging) over a short period of time much larger than would be expected from longer terms studies. While I would like to believe the conclusions drawn by the authors, I have to remain wary of accepting them.

Highlights

•Over 12 weeks, loving-kindness meditation buffered telomere attrition.

•Telomere length decreased in the mindfulness group and the control group.

•The loving-kindness group showed less telomere attrition than the control group.

Abstract

Combinations of multiple meditation practices have been shown to reduce the attrition of telomeres, the protective caps of chromosomes (Carlson et al., Cancer, 121 (2015), pp. 476-484). Here, we probed the distinct effects on telomere length (TL) of mindfulness meditation (MM) and loving-kindness meditation (LKM). Midlife adults (N = 142) were randomized to be in a waitlist control condition or to learn either MM or LKM in a 6-week workshop. Telomere length was assessed 2 weeks before the start of the workshops and 3 weeks after their termination. After controlling for appropriate demographic covariates and baseline TL, we found TL decreased significantly in the MM group and the control group, but not in the LKM group. There was also significantly less TL attrition in the LKM group than the control group. The MM group showed changes in TL that were intermediate between the LKM and control groups yet not significantly different from either. Self-reported emotions and practice intensity (duration and frequency) did not mediate these observed group differences. This study is the first to disentangle the effects of LKM and MM on TL and suggests that LKM may buffer telomere attrition.

Fig. 1. Descriptive Mean and Standard Errors of Changes in TL per Experimental Conditions. (TL is expressed as the ratio (T/S) of telomeric (T) to single copy (S) gene product for a particular blood sample)

Apart from picking apart their statistics and the "controls for demographic covariates," the discussion paragraph that troubles me most is:

The difference in telomere length between the Control and LKM groups was .048 T/S ratio after demographic covariates were considered. Based on comparison of T/S ratios and telomere length measured by Southern blot in a series of quality control samples from the same lab, we estimated this difference of .048 T/S ratio to be 115 basepairs. This TL decrease over the 12-week period appears to be large compared to studies of TL change with much longer time periods (Müezzinler et al., Obes. Rev., 15 (2014), pp. 192-201). It is possible that this reflects short term dynamic change, or potential systematic differences in the collection and/or assay of baseline and follow-up samples. The fact that DNA extraction and assay were done as one batch (all samples from Time 1 and Time 2) argues against the latter concern, although we cannot completely rule out other potential unaccounted for systematic differences. Although it is unknown whether this effect remains longer than 3 weeks post-intervention, the current study demonstrated proof of concept for the malleability of TL changes, and that certain forms of meditation, in this case loving-kindness meditation, may buffer against telomere erosion.

After several paragraphs of other reservations and cautions on the data, the authors state:

...one should interpret the differences in TL changes here with caution, treating them as evidence for “apparent” rather than true alterations in TL.

In balance, the PsyPost article title: "Study provides evidence that loving-kindness meditation slows cellular aging" is wrong.