Making Us/Them Dichotomies More Benign.

I'm reposting this item from 2016 as particularly relevant to the present.... Interesting thoughts from Robert Sapolsky:

A truly discouraging thing to me is how easily humans see the world as dichotomized between Us and Them. This comes through in all sorts of ways —social anthropology, lord of the flies, prison experiments, linguistics (all those cultures where the word for the members of that culture translates into "People," thus making a contrast with the non-people living in the next valley). 

As a neurobiologist, I'm particularly impressed with and discouraged by one finding relevant to this. There's a part of the brain called the amygdala that has lots to do with fear and anxiety and aggression. Functional brain imaging studies of humans show that the amygdala becomes metabolically active when we look at a scary face (even when the face is flashed up so quickly that we aren't consciously aware of seeing it). And some recent work—solid, done by top people, independently replicated — suggests that the amygdala can become activated when we view the face of someone from another race. The Them as scary, and the Them being someone whose skin color is real different from our own. 

Damn, that's an upsetting finding. 

But right on the heels of those studies are follow-ups showing that the picture is more complicated. The "Other skin color = scared activated amygdala = the Other" can be modified by experience. "Experience," can be how diverse of a world you grew up in. More diversity, and the amygdala is likely to become activated in that circumstance. And also, "experience," can be whether, shortly before your amygdala is put through the brain imaging paces, you are subtly biased to think about people categorically or as individuals. If you're cued towards individuating, your amygdala doesn't light up. 

Thus, it seems quite plausible to me that we are hard-wired towards making Us/Them distinctions and not being all that nice to the Them. But what is anything but hard-wired is who counts as an Us and as a Them —we are so easily manipulated into changing those categories. 

So, I'm optimistic that with the right sort of priorities and human engineering (whatever that phrase means), we can be biased towards making Us/Them dichotomies far more benign than they tend to be now. Say, by making all of us collectively feel like an Us with Them being the space aliens that may attack us some day. Or making the Them to be mean, shitty, intolerant people without compassion. 

But, I'm sure not optimistic that we'll soon be having political, religious or cultural leaders likely to move us effectively in that direction. Just to deflate that optimism.

A perky bit of piano - Haydn Fantasia in C major, glitches included

I've generated almost 5,000 posts since this blog started in 2016 (before the first iPhone was released in 2017!, seems an aeon ago.) As a diversion during my self isolation until proper testing or a vaccine appears for COVID-19, I'm scanning through these posts from their beginning, and will be passing on a few. Coming across this bit of my piano playing perked me up yesterday, and I pass it on here, a Haydn fantasia.

People aged 95 and older show stronger brain connectivity

Jiyang et al. have used resting-state functional MRI to compare 57 individuals aged 95-103 years old with 66 cognitively unimpaired younger participants aged 76-79. The centenarians showed more synchronized activation of left and right fronto-parietal control networks. Their abstract:

Highlights

We studied functional connectivity (FC) in near-centenarians and centenarians (nCC).

NCC showed stronger FC between bilateral frontoparietal control network (FPCN).

The stronger bilateral FPCN FC was linked to better visuospatial ability in nCC.

Abstract

Centenarians without dementia can be considered as a model of successful ageing and resistance against age-related cognitive decline. Is there something special about their brain functional connectivity that helps them preserve cognitive function into the 11th decade of life? In a cohort of 57 dementia-free near-centenarians and centenarians (95–103 years old) and 66 cognitively unimpaired younger participants (76–79 years old), we aimed to investigate brain functional characteristics in the extreme age range using resting-state functional MRI. Using group-level independent component analysis and dual regression, results showed group differences in the functional connectivity of seven group-level independent component (IC) templates, after accounting for sex, education years, and grey matter volume, and correcting for multiple testing at family-wise error rate of 0.05. After Bonferroni correction for testing 30 IC templates, near-centenarians and centenarians showed stronger functional connectivity between right frontoparietal control network (FPCN) and left inferior frontal gyrus (Bonferroni-corrected p ​= ​0.024), a core region of the left FPCN. The investigation of between-IC functional connectivity confirmed the voxel-wise result by showing stronger functional connectivity between bilateral FPCNs in near-centenarians and centenarians compared to young-old controls. In addition, near-centenarians and centenarians had weaker functional connectivity between default mode network and fronto-temporo-parietal network compared to young-old controls. In near-centenarians and centenarians, stronger functional connectivity between bilateral FPCNs was associated with better cognitive performance in the visuospatial domain. The current study highlights the key role of bilateral FPCN connectivity in the reserve capacity against age-related cognitive decline.

How Covid-19 stress scrambles our brains

The pandemic is providing an opportunity for a massive, real-time experiment on stress.  Even mild stress can impair the activities of the prefrontal cortex areas 'executive' functions that regulate our attentional focus and emotions. When this area grows more quiet more reactionary brain networks that it normally inhits (centering on the amygdalae) are unleashed. You should read the article by Laura Sanders that describes, with clear illustrations, experiments showing how our thoughtful planning activities are disrupted by stress.

Confront your decline head on.

I pass on another of Arthur Brook's biweekly essays in the Atlantic. This one notes that Much like contemplating death can neutralize the fear of it, it can help to acclimate yourself to the idea of losing professional skills before it happens. After describing the meditation called maranasati ("mindfulness of death") that consists of imagining nine states of one's own dead body, he offers a corresponding list to deal with decline...

I feel my competence declining.

Those close to me begin to notice that I am not as sharp as I used to be.

Other people receive the social and professional attention I used to receive.

I have to decrease my workload and step back from daily activities I once completed with ease.

I am no longer able to work.

Many people I meet do not recognize me or know me for my previous work.

I am still alive, but professionally I am no one.

I lose the ability to communicate my thoughts and ideas to those around me.

I am dead, and I am no longer remembered at all for my accomplishments.

The fear of death is much worse when it is an amorphous phantasm—something lurking menacingly in the shadows—than when it is a plain reality. And so it is with decline. Unacknowledged, it is scary. Acknowledged and contemplated, it can become a normal, natural part of life’s cadence.

It is true that Western society glorifies youthful beauty and the machinelike efficiency of homo economicus. But you don’t have to play along with our culture’s neurotic exercise in futility. Become the master who, when your social or professional standing is threatened by age or circumstance, says, “Don’t you see that I am a person who could be utterly forgotten without batting an eye?”

Do you really want to make your own complex medical decisions?

From Kassirer et al.:

Over the past several decades, the United States medical system has increasingly prioritized patient autonomy. Physicians routinely encourage patients to come to their own decisions about their medical care rather than providing patients with clearer yet more paternalistic advice. Although political theorists, bioethicists, and philosophers generally see this as a positive trend, the present research examines the important question of how patients and advisees in general react to full decisional autonomy when making difficult decisions under uncertainty. Across six experiments (N = 3,867), we find that advisers who give advisees decisional autonomy rather than offering paternalistic advice are judged to be less competent and less helpful. As a result, advisees are less likely to return to and recommend these advisers and pay them lower wages. Importantly, we also demonstrate that advisers do not anticipate these effects. We document these results both inside and outside the medical domain, suggesting that the preference for paternalism is not unique to medicine but rather is a feature of situations in which there are adviser–advisee asymmetries in expertise. We find that the preference for paternalism holds when advice is solicited or unsolicited, when both paternalism and autonomy are accompanied by expert guidance, and it persists both before and after the outcomes of paternalistic advice are realized. Lastly, we see that the preference for paternalism only occurs when decision makers perceive their decision to be difficult. These results challenge the benefits of recently adopted practices in medical decision making that prioritize full decisional autonomy.

Anxiolytic actions of oxytocin, unlike those of benzodiazepines, involve brain regions outside the amygdala

From Kreuder et al.:

Significance

A potential new target for anxiolytic drug development is the oxytocin (OXT) neuropeptide system. An emerging question is whether OXT has similar effects on the neural microcircuitry of fear compared with clinically established compounds such as benzodiazepines. The present functional MRI study showed that both OXT and its benzodiazepine comparator lorazepam (LZP) reduced centromedial amygdala responses to fear signals. OXT, but not LZP, increased extra-amygdalar connectivity between the centromedial amygdala and frontoparietal regions. Thus, while both compounds inhibited the centromedial amygdala, OXT, but not LZP, elicited large-scale connectivity changes of potential therapeutic relevance.

Abstract

Benzodiazepines (BZDs) represent the gold standard of anxiolytic pharmacotherapy; however, their clinical benefit is limited by side effects and addictive potential. Consequently, there is an urgent need to develop novel and safe anxiolytics. The peptide hormone oxytocin (OXT) exhibits anxiolytic-like properties in animals and humans, but whether OXT and BZDs share similar effects on the neural circuitry of fear is unclear. Therefore, the rationale of this ultra-high-field functional MRI (fMRI) study was to test OXT against the clinical comparator lorazepam (LZP) with regard to their neuromodulatory effects on local and network responses to fear-related stimuli. One hundred twenty-eight healthy male participants volunteered in this randomized double-blind, placebo-controlled, between-group study. Before scanning using an emotional face-matching paradigm, participants were randomly administered a single dose of OXT (24 IU), LZP (1 mg), or placebo. On the behavioral level, LZP, but not OXT, caused mild sedation, as evidenced by a 19% increase in reaction times. On the neural level, both OXT and LZP inhibited responses to fearful faces vs. neutral faces within the centromedial amygdala (cmA). In contrast, they had different effects on intra-amygdalar connectivity; OXT strengthened the coupling between the cmA and basolateral amygdala, whereas LZP increased the interplay between the cmA and superficial amygdala. Furthermore, OXT, but not LZP, enhanced the coupling between the cmA and the precuneus and dorsomedial prefrontal cortex. These data implicate inhibition of the cmA as a common denominator of anxiolytic action, with only OXT inducing large-scale connectivity changes of potential therapeutic relevance.

Your voice carries information about your upper body movements.

Fascinating observations by Pouw et al.:

Significance

We show that the human voice carries an acoustic signature of muscle 
tensioning during upper limb movements which can be detected by 
listeners. Specifically, we find that human listeners can synchronize 
their own movements to very subtle wrist movements of a vocalizer only 
by listening to their vocalizations and without any visual contact. This
study shows that the human voice contains information about dynamic 
bodily states, breaking ground for our understanding of the evolution of
spoken language and nonverbal communication. The current findings are 
in line with other research on nonhuman animals, showing that 
vocalizations carry information about bodily states and capacities.

Abstract
We show that the human voice has complex acoustic qualities that are 
directly coupled to peripheral musculoskeletal tensioning of the body, 
such as subtle wrist movements. In this study, human vocalizers produced
a steady-state vocalization while rhythmically moving the wrist or the 
arm at different tempos. Although listeners could only hear and not see 
the vocalizer, they were able to completely synchronize their own 
rhythmic wrist or arm movement with the movement of the vocalizer which 
they perceived in the voice acoustics. This study corroborates recent 
evidence suggesting that the human voice is constrained by bodily 
tensioning affecting the respiratory–vocal system. The current results 
show that the human voice contains a bodily imprint that is directly 
informative for the interpersonal perception of another’s dynamic 
physical states.

An "Apostle's Creed" for the humanistic scientific materialist?

(Note: I have begun to slowly go though the posts on MindBlog, which began in Feb. of 2006, over 14 years ago.  Here I repeat the post that appeared on March 14, 2006.  I could have written it yesterday, without changing a word.)

The classical Christian apostle's creed, over 1600 years old and formulated soon after the writing of the New Testament, is a series of "I believe....." statements. Without thinking too much about it, I've decided to quickly write down a few sentences to suggest the very different creed that I follow. Here they are:

I believe the most fundamental content of our minds to be the sensed physical breathing and moving body, a quiet awareness that underlies our surface waves of emotions and thoughts.

I believe that this awareness can begin to experience a larger process, closer to the machinery that is generating a self, a process that observes rather than being completely defined by the current narrative "I" chatter of who-I-am or what-it-is-I-do.

I believe that this awareness can expand to feel its part in a a drama of evolving life on this planet and an evolving universe - a theater much more universal than conventional cultural or religious myths.

I believe that this awareness can enhance the depth, sanity, and sensed completion of each moment. It provides a sense of wholeness and sufficiency from which actions rise. It makes contact with other humans more sane and whole.

Brain connectivity fingerprinting of complex human personality traits - another tool for the surveillance state?

A group of researchers in the Department of Radiology, Anhui Medical University, Hefei, China, find that resting-state functional connectivity patterns of whole-brain large-scale networks can effectively and reliably predict complex human personality traits, including agreeableness, openness, conscientiousness and neuroticism, at the individual level. Fascinating work, but one wonders whether this might become yet another tool that might be used by a government to assess its citizens? :

Neuroimaging studies have linked inter-individual variability in the brain to individualized personality traits. However, only one or several aspects of personality have been effectively predicted based on brain imaging features. The objective of this study was to construct a reliable prediction model of personality in a large sample by using connectome-based predictive modeling (CPM), a recently developed machine learning approach. High-quality resting-state functional magnetic resonance imaging data of 810 healthy young participants from the Human Connectome Project dataset were used to construct large-scale brain networks. Personality traits of the five-factor model (FFM) were assessed by the NEO Five Factor Inventory. We found that CPM successfully and reliably predicted all the FFM personality factors (agreeableness, openness, conscientiousness and neuroticism) other than extraversion in novel individuals. At the neural level, we found that the personality-associated functional networks mainly included brain regions within default mode, frontoparietal executive control, visual and cerebellar systems. Although different feature selection thresholds and parcellation strategies did not significantly influence the prediction results, some findings lost significance after controlling for confounds including age, gender, intelligence and head motion. Our finding of robust personality prediction from an individual’s unique functional connectome may help advance the translation of ‘brain connectivity fingerprinting’ into real-world personality psychological settings.

An explanation for human synesthesia

Fascinating work from Maurer et al.:

Synesthesia is a neurologic trait in which specific inducers, such as sounds, automatically elicit additional idiosyncratic percepts, such as color (thus “colored hearing”). One explanation for this trait—and the one tested here—is that synesthesia results from unusually weak pruning of cortical synaptic hyperconnectivity during early perceptual development. We tested the prediction from this hypothesis that synesthetes would be superior at making discriminations from nonnative categories that are normally weakened by experience-dependent pruning during a critical period early in development—namely, discrimination among nonnative phonemes (Hindi retroflex /d̪a/ and dental /ɖa/), among chimpanzee faces, and among inverted human faces. Like the superiority of 6-mo-old infants over older infants, the synesthetic groups were significantly better than control groups at making all the nonnative discriminations across five samples and three testing sites. The consistent superiority of the synesthetic groups in making discriminations that are normally eliminated during infancy suggests that residual cortical connectivity in synesthesia supports changes in perception that extend beyond the specific synesthetic percepts, consistent with the incomplete pruning hypothesis.

Social animals need connection for health and survival

Snyder-Mackler et al. have reviewed the relationships between social environment and many aspects of health and well-being across nonhuman mammals and investigated the similarities between these and patterns in humans. They found many of the same threats and responses across social mammals.

From their introduction:

The relationship between the social environment and mortality risk has been known in humans for some time, but studies in other social mammals have only recently been able to test for the same general phenomenon. These studies reveal that measures of social integration, social support, and, to a lesser extent, social status independently predict life span in at least four different mammalian orders. Despite key differences in the factors that structure the social environment in humans and other animals, the effect sizes that relate social status and social integration to natural life span in other mammals align with those estimated for social environmental effects in humans. Also like humans, multiple distinct measures of social integration have predictive value, and in the taxa examined thus far, social adversity in early life is particularly tightly linked to later-life survival.

Animal models have also been key to advancing our understanding of the causal links between social processes and health. Studies in laboratory animals indicate that socially induced stress has direct effects on immune function, disease susceptibility, and life span. Animal models have revealed pervasive changes in the response to social adversity that are detectable at the molecular level. Recent work in mice has also shown that socially induced stress shortens natural life spans owing to multiple causes, including atherosclerosis. This result echoes those in humans, in which social adversity predicts increased mortality risk from almost all major causes of death.

A comparative perspective on the social determinants of health (click to enlarge).

The obsolescence of three core operating systems that have shaped civilization for the past 350 years

I want to pass on a quotations from the beginning and end of Roger Cohen's essay on how honestly - on the 75th anniversary of the end of World War II in Europe - Germany is facing its fractured past:

“The nation-state alone does not have a future,” Angela Merkel, the German chancellor, said this week. It was a direct challenge to President Trump’s “America First,” the slogan whose poison keeps on giving. His United States has become the most unserious of nations.

Stephen Heintz, the president of the Rockefeller Brothers Fund, has written of a crisis “that stems from the growing obsolescence of three core operating systems that have shaped civilization for the past 350 years: capitalism, fueled by carbon since the dawn of the Industrial Age and increasingly driven by global financialization; the nation-state system, formalized by the Treaty of Westphalia in 1648; and representative democracy, a system of self-rule based on Enlightenment ideals of freedom, fairness, justice and equality.”

The problem is that “our practice of capitalism is both putting the planetary ecosystem at risk and generating vast economic inequality.” The nation-state is “inadequate for managing transnational challenges like global warming.” And “representative democracy is neither truly representative nor very democratic as citizens feel that self-rule has given way to rule by corporations, special interests and the wealthy.”

The virus and accompanying economic collapse have only redoubled the urgency of these reflections. This is the Age of Undoing — of world order, of international law, of truth, of America’s word. It is a dangerous time, as Germany knows better than any nation. Autocracy feeds on fear, misery, resentment and lies. It did in the 1930s; it does now. Better to love your country with a broken heart than to love it blind.

Rules for identifying your life's work.

During this time of virtual or postponed college graduations, Arthur Brooks does a relevant installment in his bi-weekly series for Atlantic Magazine. I'm going to pass on just sentence or two of each of his rules for graduates in finding your calling, and suggest you read the whole article:  

Rule 1. The work has to be the reward.

One of the biggest mistakes people make in their careers is to treat work primarily as a means to an end. Whether that end is money, power, or prestige, this instrumentalization of work leads to unhappiness.

Rule 2. An interesting career is better than a fun career.

Interest is considered by many neuroscientists to be a positive primary emotion, processed in the limbic system of the brain. Something that truly interests you is intensely pleasurable; it also must have meaning in order to hold your interest. Thus, “Is this work deeply interesting to me?” is a helpful litmus test of [for] a job.

Rule 3. A career doesn’t have to be a straight line.

Scholars at the University of Southern California have studied career patterns and come up with four broad categories. The first are linear careers, which climb steadily upward, with everything building on everything else...There are three others. Steady-state careers involve staying at one job and growing in expertise. Transitory careers are ones in which people jump from job to job or even field to field, looking for new challenges. Spiral careers, the last category, are more like a series of mini careers—people spend many years developing in a profession, then shift fields seeking not just for novelty, but for work that builds on the skills of their previous mini careers.

Rule 4. Beware of unhealthy passions.

This rule refines Rule 3. Yes, look for something in which you are intensely interested. But go further and ask, “Is my interest obsessive, or harmonious? Does this job or career bring out the best in me? Does it make me a happier, better person, or, in pursuing it, am I neglecting other important things life has to offer?”

AI for social good: Well meaning gobbledegook

I pass on this link to a my-eyes-glaze-over open access perspective on international efforts to use artificial intelligence for social good. The effort is a noble one, and indeed tries to deal with a very complex domain. Here is the abstract, which introduces the first of an array of acronyms:

Advances in machine learning (ML) and artificial intelligence (AI) present an opportunity to build better tools and solutions to help address some of the world’s most pressing challenges, and deliver positive social impact in accordance with the priorities outlined in the United Nations’ 17 Sustainable Development Goals (SDGs). The AI for Social Good (AI4SG) movement aims to establish interdisciplinary partnerships centred around AI applications towards SDGs. We provide a set of guidelines for establishing successful long-term collaborations between AI researchers and application-domain experts, relate them to existing AI4SG projects and identify key opportunities for future AI applications targeted towards social good.

Added note: I almost never respond positively to emails requesting that I link to a particular advocacy or commercial site, but I make an exception on receiving this morning email on 8/12/2020:

My name is Sean from Don’t Panic. We’re a Creative Advertising agency in London passionate about creating cause-related advertising campaigns for charities and brands.

I am a fan of your website and I noticed that you linked to a Nature resource discussing social good on this page https://mindblog.dericbownds.net/2020/05/ai-for-social-good-well-meaning.html.

I have put together an article exploring what social good is. I think that your readers would find this very useful. You can find it here: https://www.dontpaniclondon.com/what-is-social-good/

I’d be very grateful if you considered linking to my article in addition to the Nature resource.

Ketogenic diet enhances brain network stability, a biomarker of aging

Mujica-Parodi et al. make observations suggesting that diets that changes the predominant dietary fuel from glucose (from carbohydrates) to ketones (from fats) increase available energy and enhance functional communication between brain regions, thus showing potential in protecting the aging brain. 

Significance

To better understand how diet influences brain aging, we focus here on the presymptomatic period during which prevention may be most effective. Large-scale life span neuroimaging datasets show functional communication between brain regions destabilizes with age, typically starting in the late 40s, and that destabilization correlates with poorer cognition and accelerates with insulin resistance. Targeted experiments show that this biomarker for brain aging is reliably modulated with consumption of different fuel sources: Glucose decreases, and ketones increase the stability of brain networks. This effect replicated across both changes to total diet as well as fuel-specific calorie-matched bolus, producing changes in overall brain activity that suggest that network “switching” may reflect the brain’s adaptive response to conserve energy under resource constraint.

Abstract

Epidemiological studies suggest that insulin resistance accelerates progression of age-based cognitive impairment, which neuroimaging has linked to brain glucose hypometabolism. As cellular inputs, ketones increase Gibbs free energy change for ATP by 27% compared to glucose. Here we test whether dietary changes are capable of modulating sustained functional communication between brain regions (network stability) by changing their predominant dietary fuel from glucose to ketones. We first established network stability as a biomarker for brain aging using two large-scale (n = 292, ages 20 to 85 y; n = 636, ages 18 to 88 y) 3 T functional MRI (fMRI) datasets. To determine whether diet can influence brain network stability, we additionally scanned 42 adults, age < 50 y, using ultrahigh-field (7 T) ultrafast (802 ms) fMRI optimized for single-participant-level detection sensitivity. One cohort was scanned under standard diet, overnight fasting, and ketogenic diet conditions. To isolate the impact of fuel type, an independent overnight fasted cohort was scanned before and after administration of a calorie-matched glucose and exogenous ketone ester (d-β-hydroxybutyrate) bolus. Across the life span, brain network destabilization correlated with decreased brain activity and cognitive acuity. Effects emerged at 47 y, with the most rapid degeneration occurring at 60 y. Networks were destabilized by glucose and stabilized by ketones, irrespective of whether ketosis was achieved with a ketogenic diet or exogenous ketone ester. Together, our results suggest that brain network destabilization may reflect early signs of hypometabolism, associated with dementia. Dietary interventions resulting in ketone utilization increase available energy and thus may show potential in protecting the aging brain.

How Social Networks are destroying democracy.

In the December 2019 issue of The Atlantic Haidt and Rose-Stockwell offer a must-read article titled "The Dark Psychology of Social Networks." It begins with a thought experiment asks us to imagine what chaos would result if God became bored and decided to double the gravitational constant. Birds would falls from the sky, buildings would collapse, etc.

Let’s rerun this thought experiment in the social and political world, rather than the physical one. The U.S. Constitution was an exercise in intelligent design. The Founding Fathers knew that most previous democracies had been unstable and short-lived. But they were excellent psychologists, and they strove to create institutions and procedures that would work with human nature to resist the forces that had torn apart so many other attempts at self-governance...James Madison wrote about his fear of the power of “faction,” by which he meant strong partisanship or group interest that “inflamed [men] with mutual animosity” and made them forget about the common good...The Constitution included mechanisms to slow things down, let passions cool, and encourage reflection and deliberation.

Madison’s design has proved durable. But what would happen to American democracy if, one day in the early 21st century, a technology appeared that—over the course of a decade—changed several fundamental parameters of social and political life? What if this technology greatly increased the amount of “mutual animosity” and the speed at which outrage spread? Might we witness the political equivalent of buildings collapsing, birds falling from the sky, and the Earth moving closer to the sun?

What Social Media Changed....The problem may not be connectivity itself but rather the way social media turns so much communication into a public performance...social psychologist Mark Leary coined the term sociometer to describe the inner mental gauge that tells us, moment by moment, how we’re doing in the eyes of others...Social media, with its displays of likes, friends, followers, and retweets, has pulled our sociometers out of our private thoughts and posted them for all to see...Human beings evolved to gossip, preen, manipulate, and ostracize. We are easily lured into this new gladiatorial circus, even when we know that it can make us cruel and shallow...In other words, social media turns many of our most politically engaged citizens into Madison’s nightmare: arsonists who compete to create the most inflammatory posts and images, which they can distribute across the country in an instant while their public sociometer displays how far their creations have traveled...Citizens are now more connected to one another, on platforms that have been designed to make outrage contagious.

Is There Any Way Back?...Social media has changed the lives of millions of Americans with a suddenness and force that few expected...citizens are now more connected to one another, in ways that increase public performance and foster moral grandstanding, on platforms that have been designed to make outrage contagious, all while focusing people’s minds on immediate conflicts and untested ideas, untethered from traditions, knowledge, and values that previously exerted a stabilizing effect. This, we believe, is why many Americans—and citizens of many other countries, too—experience democracy as a place where everything is going haywire...It doesn’t have to be this way...Many researchers, legislators, charitable foundations, and tech-industry insiders are now working together in search of ... improvements. We suggest three types of reform that might help:

(1) Reduce the frequency and intensity of public performance. If social media creates incentives for moral grandstanding rather than authentic communication, then we should look for ways to reduce those incentives. One such approach already being evaluated by some platforms is “demetrication,” the process of obscuring like and share counts so that individual pieces of content can be evaluated on their own merit, and so that social-media users are not subject to continual, public popularity contests.

(2) Reduce the reach of unverified accounts. Bad actors—trolls, foreign agents, and domestic provocateurs—benefit the most from the current system, where anyone can create hundreds of fake accounts and use them to manipulate millions of people. Social media would immediately become far less toxic, and democracies less hackable, if the major platforms required basic identity verification before anyone could open an account—or at least an account type that allowed the owner to reach large audiences. (Posting itself could remain anonymous, and registration would need to be done in a way that protected the information of users who live in countries where the government might punish dissent. For example, verification could be done in collaboration with an independent nonprofit organization.)

(3) Reduce the contagiousness of low-quality information. Social media has become more toxic as friction has been removed. Adding some friction back in has been shown to improve the quality of content. For example, just after a user submits a comment, AI can identify text that’s similar to comments previously flagged as toxic and ask, “Are you sure you want to post this?” This extra step has been shown to help Instagram users rethink hurtful messages. The quality of information that is spread by recommendation algorithms could likewise be improved by giving groups of experts the ability to audit the algorithms for harms and biases.

If we want our democracy to succeed—indeed, if we want the idea of democracy to regain respect in an age when dissatisfaction with democracies is rising—we’ll need to understand the many ways in which today’s social-media platforms create conditions that may be hostile to democracy’s success. And then we’ll have to take decisive action to improve social media.

Closing the gap between mind and brain - The dynamic connectome and psilocybin

Quiroga summaries elegant work by Kringelbach et al.,

...who provide a framework for incorporating into the connectome the dynamic variations caused by neuromodulatory systems...The main tenet of [their work] is that neurotransmitters’ systems can modulate the connectome over time, thus enabling a plethora of behaviors with the same underlying structural connectivity. To this end, a modeling approach is presented, in which the structural connectivity is estimated through diffusion MRI, and is coupled to the neurotransmitter system, estimated from positron electron tomography data. Both systems are portrayed by a set of mutually coupled dynamic equations, which are used to fit the functional connectivity, obtained from functional MRI. This approach was tested by exploring the effects that a psychedelic drug (psilocybin) had on neuronal activity, showing that the dynamically coupled neuronal and neuromodulatory systems give a significantly better fit to the measured data, compared to alternative models in which both systems were uncoupled, or in which the neuromodulatory system, rather than being dynamically updated, was frozen in time.

I pass on the Kringelbach et al. significance statement (not distinguished by its modesty) and abstract. The article is open source,and has excellent graphics and figures.  

Significance

In a technical tour de force, we have created a framework demonstrating the underlying fundamental principles of bidirectional coupling of neuronal and neurotransmitter dynamical systems. Specifically, in the present study, we combined multimodal neuroimaging data to causally explain the functional effects of specific serotoninergic receptor (5-HT2AR) stimulation with psilocybin in healthy humans. Longer term, this could provide a better understanding of why psilocybin is showing considerable promise as a therapeutic intervention for neuropsychiatric disorders including depression, anxiety, and addiction.

Abstract

Remarkable progress has come from whole-brain models linking anatomy and function. Paradoxically, it is not clear how a neuronal dynamical system running in the fixed human anatomical connectome can give rise to the rich changes in the functional repertoire associated with human brain function, which is impossible to explain through long-term plasticity. Neuromodulation evolved to allow for such flexibility by dynamically updating the effectivity of the fixed anatomical connectivity. Here, we introduce a theoretical framework modeling the dynamical mutual coupling between the neuronal and neurotransmitter systems. We demonstrate that this framework is crucial to advance our understanding of whole-brain dynamics by bidirectional coupling of the two systems through combining multimodal neuroimaging data (diffusion magnetic resonance imaging [dMRI], functional magnetic resonance imaging [fMRI], and positron electron tomography [PET]) to explain the functional effects of specific serotoninergic receptor (5-HT2AR) stimulation with psilocybin in healthy humans. This advance provides an understanding of why psilocybin is showing considerable promise as a therapeutic intervention for neuropsychiatric disorders including depression, anxiety, and addiction. Overall, these insights demonstrate that the whole-brain mutual coupling between the neuronal and the neurotransmission systems is essential for understanding the remarkable flexibility of human brain function despite having to rely on fixed anatomical connectivity.

Anti-Intellectualism, Populism, and Motivated Resistance to Expert Consensus

I want to pass on the abstract from Eric Merkley's article in Public Opinion Quarterly. I fervently hope that the anti-intellectuals he describes do not form a majority of those voting in the November election.

Scholars have maintained that public attitudes often diverge from expert consensus due to ideology-driven motivated reasoning. However, this is not a sufficient explanation for less salient and politically charged questions. More attention needs to be given to anti-intellectualism—the generalized mistrust of intellectuals and experts. Using data from the General Social Survey and a survey of 3,600 Americans on Amazon Mechanical Turk, I provide evidence of a strong association between anti-intellectualism and opposition to scientific positions on climate change, nuclear power, GMOs, and water fluoridation, particularly for respondents with higher levels of political interest. Second, a survey experiment shows that anti-intellectualism moderates the acceptance of expert consensus cues such that respondents with high levels of anti-intellectualism actually increase their opposition to these positions in response. Third, evidence shows anti-intellectualism is connected to populism, a worldview that sees political conflict as primarily between ordinary citizens and a privileged societal elite. Exposure to randomly assigned populist rhetoric, even that which does not pertain to experts directly, primes anti-intellectual predispositions among respondents in the processing of expert consensus cues. These findings suggest that rising anti-elite rhetoric may make anti-intellectual sentiment more salient in information processing.

Meet the psychobiome

Elizabeth Pennisi does a piece on the search for new brain drugs in human poop, generated by the ~ 2 kilograms of bacteria, fungi, viruses, and archaea that live in our gut.

..with as many as 20 million genes among them, those microbes pack a genomic punch that our measly 20,000 genes can't match. Gut bacteria can make and use nutrients and other molecules in ways the human body can't — a tantalizing source of new therapies.

Holobiome, a small startup company,...plans to capitalize on growing evidence from epidemiological and animal studies that link gut bacteria to conditions as diverse as autism, anxiety, and Alzheimer's disease. Since its founding a mere 5 years ago, Holobiome has created one of the world's largest collections of human gut microbes...A growing number of researchers see a promising alternative in microbe-based treatments, or “psychobiotics,”... the targeted ailments include depression and insomnia, as well as constipation, and visceral pain like that typical of irritable bowel syndrome—conditions that may have neurological as well as intestinal components.

One interesting approach involves finding bacteria that secrete the inhibitory neurotransmitter GABA.

One growth factor Strandwitz identified turned out to be the key to launching his entrepreneurial dreams. He and colleagues isolated a bacterium that couldn't survive on typical culture media and required an amino acid called gamma-aminobutyric acid (GABA) to thrive. GABA is a neurotransmitter that inhibits neural activity in the brain, and its misregulation has been linked to depression and other mental health problems.

The researchers reasoned that if this gut microbe had to have GABA, some other microbe must be making it. Such GABA producers might be a psychobiotic gold mine. Strandwitz and colleagues began to add gut microbes one at a time to petri dishes containing the GABA eater. If the GABA eater thrived, the scientists would know they'd found a GABA producer. They discovered such producers among three groups of bacteria, including Bactereroides. They quickly filed a patent for packaging those bacteria—or their products—to treat people with depression or other mental disorders.

Before publishing those findings, the group teamed up with researchers at Weill Cornell Medicine who were doing a brain scan study of 23 people diagnosed with depression. They found that people with fewer Bacteroides bacteria had a stronger pattern of hyperactivity in the prefrontal cortex, which some researchers have associated with severe depression. The collaboration reported its findings on 10 December 2018 in Nature Microbiology, along with the discovery of GABA-producing bacteria.

GABA is too big to reach the brain by slipping across the blood-brain barrier, a cellular defense wall that limits the size and types of molecules that can get into the brain from blood vessels. Instead, the molecule may act through the vagus nerve or the enteroendocrine cells. Some researchers might question why bacteria would be any more beneficial than GABA-boosting drugs. But Strandwitz says the bacteria may do more than simply boost GABA. He notes that they produce molecules that may have other effects on the brain and body, thereby addressing other symptoms of depression.

Arthur Brooks on "The Hero's Journey" and retirement

In the most recent installment of Arthur Brooks’ biweekly column in The Atlantic, which I suggest that you read, he talks about the classical hero's journey in literature, described by Carl Jung and Joseph Campbell as a lens through which many people see their lives:

It’s a nice narrative, especially if you’ve worked hard and done pretty well in life. The problem is the real-life ending, after the triumphant return...The hero’s journey is great when you’re in the middle of it. The trouble comes when your strengths start to wane, because now you’re off script...Joseph Campbell...notes that...“The first problem of the returning hero is to accept as real, after an experience of the soul-satisfying vision of fulfillment, the passing joys and sorrows, banalities and noisy obscenities of life.” In other words, the end of the true hero’s journey is coming home and finding a battle to be waged not with an external enemy, but with one’s own demons...your skills will decline, and life’s problems will intrude. If you try to hang on to glory, or lash out when it fades, it will squander your victories and mark an unhappy end to your journey.

Plan to spend the last part of your life serving others, loving your family and friends, and being a good example to those still in the first three stages of their own hero’s journey. Happiness in retirement depends on your choice of narrative.

Young blood plasma reverses the epigenetic aging clock.

Perhaps the best molecular biomarker of aging at present is the epigenetic clock, developed by Horvath and others, based on measurements of DNA methylation. Josh Mitteldorf points to experiments by Horvath et al. recently posted in a preprint (not yet reviewed) in bioRxiv. noting how methylation patterns characteristic of aging can be reversed.

...plasma treatment of the old rats [109 weeks] reduced the epigenetic ages of blood, liver and heart by a very large and significant margin, to levels that are comparable with the young rats [30 weeks]….According to the final version of the epigenetic clocks, the average rejuvenation across four tissues was 54.2%. In other words, the treatment more than halved the epigenetic age.

Their abstract:

Young blood plasma is known to confer beneficial effects on various organs in mice. However, it was not known whether young plasma rejuvenates cells and tissues at the epigenetic level; whether it alters the epigenetic clock, which is a highly-accurate molecular biomarker of aging. To address this question, we developed and validated six different epigenetic clocks for rat tissues that are based on DNA methylation values derived from n=593 tissue samples. As indicated by their respective names, the rat pan-tissue clock can be applied to DNA methylation profiles from all rat tissues, while the rat brain-, liver-, and blood clocks apply to the corresponding tissue types. We also developed two epigenetic clocks that apply to both human and rat tissues by adding n=850 human tissue samples to the training data. We employed these six clocks to investigate the rejuvenation effects of a plasma fraction treatment in different rat tissues. The treatment more than halved the epigenetic ages of blood, heart, and liver tissue. A less pronounced, but statistically significant, rejuvenation effect could be observed in the hypothalamus. The treatment was accompanied by progressive improvement in the function of these organs as ascertained through numerous biochemical/physiological biomarkers and behavioral responses to assess cognitive functions. Cellular senescence, which is not associated with epigenetic aging, was also considerably reduced in vital organs. Overall, this study demonstrates that a plasma-derived treatment markedly reverses aging according to epigenetic clocks and benchmark biomarkers of aging.

Take the shutdown skeptics seriously.

I have been holding back from doing posts on the current pandemic, since it completely dominates the popular press. However, I want to pass on this link to one sane piece done by Conor Friedersdorf, a staff writer at The Atlantic. I will just paste in one key paragraph here, and urge you to read the whole piece.

If we knew that a broadly effective COVID-19 treatment was imminent, or that a working vaccine was months away, minimizing infections through social distancing until that moment would be the right course. At the other extreme, if we will never have an effective treatment or vaccine and most everyone will get infected eventually, then the costs of social distancing are untenable. We don’t know where we sit on that spectrum. So we cannot know what the best way forward is even if we place the highest possible value on preserving life and protecting the vulnerable.

That uncertainty means, at the very least, that Americans should carefully consider the potential costs of prolonged shutdowns lest they cause more deaths or harm to the vulnerable than they spare.

Self, purpose, and tribal mentality as Darwinian adaptations (or…Why why aren’t we all enlightened?)

This is a post like the one I offered on March 13 that passes on a bit of writing that I think might develop into a longer piece of work. I hope the following ideas and assertions make some sense to readers:

One ultimate cause of human behaviors is the endless cycling of a “Darwin machine,” operating at the level of cells, individuals, and groups of humans. As entities - from the most simple virus particles to complex human cultures - reproduce or renew themselves to persist through time, small errors or variations that end up enhancing reproductive fitness become dominant in the population. The grand master is multilevel selection, and there is a conflict between individual-level selection (individuals competing with other individuals in the same group) and group-level selection (competition between groups). Within groups selfish individuals beat altruistic individuals, but groups of altruists beat groups of selfish individuals. E.O. Wilson risks the oversimplification of suggesting that individual selection promoted sin, while group selection promoted virtue.

The array of social emotions supporting tribal cultures that have occupied most of human history, as well as the more recent emergence of language, thought, and material culture, can be rationalized with this model. Taken together, they have enabled formation of large complex societies bonded together by laws, religions, and assumptions about purpose, meaning, and self that are unique to modern humans.

Nations and religions link language and meaning to more ancient evolved instinctive social emotional behaviors that bond groups of humans and other primates. This link is revealed when logic and language are turned inward (by both ancient meditative traditions as well as modern neuroscience) in a way that reveals that our common experiences of self or purpose are confabulations, or illusions - illusions nevertheless that have been necessary for forming complex human linguistic cultures, illusions which our emotional hormones and nerve circuitry have evolved to support.

Given the clear scientific evidence, why don’t we transcend these evolved linkages between our biology and our illusions? Why have those regarded as spiritually ‘enlightened’ throughout history remained a small minority of the population? Perhaps it is because those who become enlightened or awakened to the illusory nature of the self are granted a perspective on basic emotional drives that can divests them of much of their power. Enlightenment is subtle, not noisy, it doesn't engage the passions as well as blind devotion to nations and gods. This is why secular humanism, with its more muted versions of spirituality (‘I’m spiritual but not religious’) finds it difficult to compete with the ego-rich passions of nationalism and theism.

Because our evolved social brains incline us to cling to a complex array of nations, religions, and tribal identities that parse the world into ‘us’ and ‘them,’ we find it difficult to accept that we are a common humanity that would most effectively face our current pandemic and environmental crises by joining together.

Infant behavioral inhibition predicts personality and social outcomes three decades later

From Tang et al.:

Significance

Children show different temperamental styles early in development. Whether temperament predicts who children become as adults and how early we can predict these outcomes have been long-standing questions of interest to the scientific and public community. The current study used rigorous methods to characterize an inhibited temperament by 14 mo of age in a cohort of infants and followed them for three decades. We provide the strongest and earliest evidence showing that infants with an inhibited temperament at 14 mo became introverted adults, with poorer functioning in some social and mental health domains. Also, brain activity underlying cognitive control in adolescence was associated with adult mental health. These findings highlight the lasting influence of early temperament on social-emotional development.

Abstract

Does infant temperament predict adult personality and life-course patterns? To date, there is scant evidence examining relations between child temperament and adult outcomes, and extant research has relied on limited methods for measuring temperament such as maternal report. This prospective longitudinal study followed a cohort of infants (n = 165) for three decades to examine whether infant behavioral inhibition, a temperament characterized by cautious and fearful behaviors to unfamiliar situations, shapes long-term personality, social relationships, vocational/education, and mental health outcomes in adulthood. At age 14 mo, behavioral inhibition was assessed using an observation paradigm. In adolescence (15 y; n = 115), error monitoring event-related potentials were measured in a flanker task. In adulthood (26 y; n = 109), personality, psychopathology, and sociodemographics were self-reported using questionnaires. We found that infants with higher levels of behavioral inhibition at 14 mo grew up to become more reserved and introverted adults (β = 0.34) with lower social functioning with friends and family (β = −0.23) at age 26. Infant behavioral inhibition was also a specific risk factor for adult internalizing (i.e., anxiety and depression, β = 0.20) psychopathology, rather than a transdiagnostic risk for general and externalizing psychopathology. We identified a neurophysiologic mechanism underlying risk and resilience for later psychopathology. Heightened error monitoring in adolescence moderated higher levels of adult internalizing psychopathology among behaviorally inhibited individuals. These findings suggest meaningful continuity between infant temperament and the development of adult personality. They provide the earliest evidence suggesting that the foundation of long-term well-being is rooted in individual differences in temperament observed in infancy.

Future of the Human climate niche

Sobering analysis from Xu et al. :

Significance

We show that for thousands of years, humans have concentrated in a surprisingly narrow subset of Earth’s available climates, characterized by mean annual temperatures around ∼13 °C. This distribution likely reflects a human temperature niche related to fundamental constraints. We demonstrate that depending on scenarios of population growth and warming, over the coming 50 y, 1 to 3 billion people are projected to be left outside the climate conditions that have served humanity well over the past 6,000 y. Absent climate mitigation or migration, a substantial part of humanity will be exposed to mean annual temperatures warmer than nearly anywhere today.

Abstract

All species have an environmental niche, and despite technological advances, humans are unlikely to be an exception. Here, we demonstrate that for millennia, human populations have resided in the same narrow part of the climatic envelope available on the globe, characterized by a major mode around ∼11 °C to 15 °C mean annual temperature (MAT). Supporting the fundamental nature of this temperature niche, current production of crops and livestock is largely limited to the same conditions, and the same optimum has been found for agricultural and nonagricultural economic output of countries through analyses of year-to-year variation. We show that in a business-as-usual climate change scenario, the geographical position of this temperature niche is projected to shift more over the coming 50 y than it has moved since 6000 BP. Populations will not simply track the shifting climate, as adaptation in situ may address some of the challenges, and many other factors affect decisions to migrate. Nevertheless, in the absence of migration, one third of the global population is projected to experience a MAT >29 °C currently found in only 0.8% of the Earth’s land surface, mostly concentrated in the Sahara. As the potentially most affected regions are among the poorest in the world, where adaptive capacity is low, enhancing human development in those areas should be a priority alongside climate mitigation.

The Diversity–Innovation Paradox in Science

From Hofstra et al:  

Significance

By analyzing data from nearly all US PhD recipients and their dissertations across three decades, this paper finds demographically underrepresented students innovate at higher rates than majority students, but their novel contributions are discounted and less likely to earn them academic positions. The discounting of minorities’ innovations may partly explain their underrepresentation in influential positions of academia.

Abstract

Prior work finds a diversity paradox: Diversity breeds innovation, yet underrepresented groups that diversify organizations have less successful careers within them. Does the diversity paradox hold for scientists as well? We study this by utilizing a near-complete population of ∼1.2 million US doctoral recipients from 1977 to 2015 and following their careers into publishing and faculty positions. We use text analysis and machine learning to answer a series of questions: How do we detect scientific innovations? Are underrepresented groups more likely to generate scientific innovations? And are the innovations of underrepresented groups adopted and rewarded? Our analyses show that underrepresented groups produce higher rates of scientific novelty. However, their novel contributions are devalued and discounted: For example, novel contributions by gender and racial minorities are taken up by other scholars at lower rates than novel contributions by gender and racial majorities, and equally impactful contributions of gender and racial minorities are less likely to result in successful scientific careers than for majority groups. These results suggest there may be unwarranted reproduction of stratification in academic careers that discounts diversity’s role in innovation and partly explains the underrepresentation of some groups in academia.

The cultural origins of metacognition.

I want to pass on this open source article in Trends in Cognitive Science by Heyes et al. Their summary:

Highlights

Human metacognition involves discrimination, interpretation, and broadcasting of subtle cues indicating the rightness of ongoing thought and behaviour.

We propose that human metacognition is made fit for purpose by cultural evolution rather than genetic evolution.

In particular, we present evidence that the effective discrimination, interpretation, and broadcasting of metacognitive cues depends on cultural learning.

The cultural origins hypothesis advances a programme of research on the development of metacognition, cultural variation, individual differences, and cross-species comparisons.

Metacognition – the ability to represent, monitor and control ongoing cognitive processes – helps us perform many tasks, both when acting alone and when working with others. While metacognition is adaptive, and found in other animals, we should not assume that all human forms of metacognition are gene-based adaptations. Instead, some forms may have a social origin, including the discrimination, interpretation, and broadcasting of metacognitive representations. There is evidence that each of these abilities depends on cultural learning and therefore that cultural selection might shape human metacognition. The cultural origins hypothesis is a plausible and testable alternative that directs us towards a substantial new programme of research.

Rising workplace inequalities in high-income countries.

From Tomaskovic-Devey et al.:

Significance

Understanding the causes of rising inequality is of concern in many countries. Using administrative data, we find that the share of inequality that is between workplaces is growing in 12 of 14 countries examined, and in no country has it fallen. Countries with declining employment protections see growth in both between- and within-workplace inequalities, but this impact is stronger for between-workplace inequalities. These results suggest that to reduce market income inequality requires policies that raise the bargaining power of lower-skilled workers. The widespread rise in between-workplace inequality additionally suggests policy responses that target the increasing market power of firms in concentrated markets as well as curb the ability of powerful firms to outsource low skill employment.

Abstract

It is well documented that earnings inequalities have risen in many high-income countries. Less clear are the linkages between rising income inequality and workplace dynamics, how within- and between-workplace inequality varies across countries, and to what extent these inequalities are moderated by national labor market institutions. In order to describe changes in the initial between- and within-firm market income distribution we analyze administrative records for 2,000,000,000+ job years nested within 50,000,000+ workplace years for 14 high-income countries in North America, Scandinavia, Continental and Eastern Europe, the Middle East, and East Asia. We find that countries vary a great deal in their levels and trends in earnings inequality but that the between-workplace share of wage inequality is growing in almost all countries examined and is in no country declining. We also find that earnings inequalities and the share of between-workplace inequalities are lower and grew less strongly in countries with stronger institutional employment protections and rose faster when these labor market protections weakened. Our findings suggest that firm-level restructuring and increasing wage inequalities between workplaces are more central contributors to rising income inequality than previously recognized.

How do cognition-enhancing drugs work?

Westbrook et al. do experiments with drugs influencing dopamine levels that suggest that cognition-enhancing drugs may act at the motivational level rather than directly boosting cognition per se.

Stimulants such as methylphenidate are increasingly used for cognitive enhancement but precise mechanisms are unknown. We found that methylphenidate boosts willingness to expend cognitive effort by altering the benefit-to-cost ratio of cognitive work. Willingness to expend effort was greater for participants with higher striatal dopamine synthesis capacity, whereas methylphenidate and sulpiride, a selective D2 receptor antagonist, increased cognitive motivation more for participants with lower synthesis capacity. A sequential sampling model informed by momentary gaze revealed that decisions to expend effort are related to amplification of benefit-versus-cost information attended early in the decision process, whereas the effect of benefits is strengthened with higher synthesis capacity and by methylphenidate. These findings demonstrate that methylphenidate boosts the perceived benefits versus costs of cognitive effort by modulating striatal dopamine signaling.

Why does awe have prosocial effects?

An interesting perspective from Perlin and Li:

Awe is an emotional response to stimuli that are perceived to be vast (e.g., tall trees, sunsets) and that defy accommodation by existing mental structures. Curiously, awe has prosocial effects despite often being elicited by nonsocial stimuli. The prevailing explanation for why awe has prosocial effects is that awe reduces attention to self-oriented concerns (i.e., awe makes the self small), thereby making more attention available for other-oriented concerns. However, several questions remain unaddressed by the current formulation of this small-self hypothesis. How are awe researchers defining the self, and what implications might their theory of selfhood have for understanding the “smallness” of the self? Building on theories regarding psychological selfhood, we propose that awe may interact with the self not just in terms of attentional focus but rather at multiple layers of selfhood. We further reinterpret the small self using the notion of the quiet ego from personality psychology. Linking awe to an enriched model of the self provided by personality psychology may be fruitful for explaining a range of phenomena and motivating future research.

Evidence that aerobic exercise reverses aging.

Brett et al. show (in mice) that aerobic exercise rejuvenates quiescent skeletal muscle stem cells in old mice and accelerates muscle tissue repair:

Ageing impairs tissue repair. This defect is pronounced in skeletal muscle, whose regeneration by muscle stem cells (MuSCs) is robust in young-adult animals, but inefficient in older organisms. Despite this functional decline, old MuSCs are amenable to rejuvenation through strategies that improve the systemic milieu, such as heterochronic parabiosis [i.e. connecting the circulatory systems of young and old mice). One such strategy, exercise, has long been appreciated for its benefits on healthspan, but its effects on aged stem-cell function in the context of tissue regeneration are incompletely understood. Here, we show that exercise in the form of voluntary wheel running accelerates muscle repair in old mice and improves old MuSC function. Through transcriptional profiling and genetic studies, we discovered that the restoration of old MuSC activation ability hinges on restoration of Cyclin D1, whose expression declines with age in MuSCs. Pharmacologic studies revealed that Cyclin D1 maintains MuSC activation capacity by repressing TGF-β signalling. Taken together, these studies demonstrate that voluntary exercise is a practicable intervention for old MuSC rejuvenation. Furthermore, this work highlights the distinct role of Cyclin D1 in stem-cell quiescence.

Non-invasive DIY brain stimulators are a bad idea.

I must admit that I've been sorely tempted to have a try with one of the transcranial magnetic or direct current stimulators, easily ordered from web vendors, whose use is claimed to enhance your smarts or chill you out. A meta-analysis by Smits et al. casts cold water on the prospects of these working as advertised.

Excessive emotional responses to stressful events can detrimentally affect psychological functioning and mental health. Recent studies have provided evidence that non-invasive brain stimulation (NBS) targeting the prefrontal cortex (PFC) can affect the regulation of stress-related emotional responses. However, the reliability and effect sizes have not been systematically analyzed. In the present study, we reviewed and meta-analyzed the effects of repetitive transcranial magnetic (rTMS) and transcranial direct current stimulation (tDCS) over the PFC on acute emotional stress reactivity in healthy individuals. Forty sham-controlled single-session rTMS and tDCS studies were included. Separate random effects models were performed to estimate the mean effect sizes of emotional reactivity. Twelve rTMS studies together showed no evidence that rTMS over the PFC influenced emotional reactivity. Twenty-six anodal tDCS studies yielded a weak beneficial effect on stress-related emotional reactivity (Hedges’ g = −0.16, CI95% = [−0.33, 0.00]). These findings suggest that a single session of NBS is insufficient to induce reliable, clinically significant effects but also provide preliminary evidence that specific NBS methods can affect emotional reactivity. This may motivate further research into augmenting the efficacy of NBS protocols on stress-related processes.

The deep historical roots of global economic inequality

Nathan Nunn does an article which describes how a substantial part of the world’s current income differences can be explained by the divergent effects of European contact globally, beginning in the late 15th century with Christopher Columbus’ arrival to the Americas in 1492, which resulted in a massive transfer of disease, food, ideas, and people between the Old World and the New World. The colonization of people of color by white Europeans and particularly the enslavement of black people starting ~500 year ago has left an enduring legacy that is hard to overcome.

I pass on Figure 1 from the paper and its discussion. It shows the evolution of economic prosperity, measured using the natural logarithm of real per capita gross domestic product, for different regions of the world from 1000 to 2000 CE.

1) The best predictor of a region’s relative income in a period is its income in the years prior. A perfect predictor of the relative ranking of regional prosperity in 2000 is the ranking in 1800. If one considers income further back in time (e.g., 1500), one finds that it is still a very good indicator, although not a perfect one.

2) The sizable differences in relative incomes that we observe today have not always been present. (Today, the richest countries in the world are about 42 times as rich as the poorest.) These differences appear to have first emerged in 1500 and to have increased starting in the 18th century, a process that has been called the “Great Divergence” (2).

3) Although there is a remarkable amount of historical persistence in comparative development, there are some important exceptions. In particular, the region “Western European offshoots,” which comprises land that today is Canada, United States, Australia, and New Zealand, moves from being the poorest region of the world in 1600 (and before) to the richest in 1800 (and after).

Changes in cerebral cortex functional organization in healthy elderly.

Sigh.... Chong et al. offer a picture of how my 78 year old brain is more muddled than that of a ~23 year old male.

SIGNIFICANCE STATEMENT

Cross-sectional studies have demonstrated age-related reductions in the functional segregation and distinctiveness of brain networks. However, longitudinal aging-related changes in brain functional modular architecture and their links to cognitive decline remain relatively understudied. Using graph theoretical and community detection approaches to study task-free functional network changes in a cross-sectional young and longitudinal healthy elderly cohort, we showed that aging was associated with global declines in network segregation, integration, and module distinctiveness, and specific declines in distinctiveness of higher-order cognitive networks. Further, such functional network deterioration was associated with poorer cognitive performance cross-sectionally. Our findings suggest that healthy aging is associated with system-level changes in brain functional modular organization, accompanied by functional segregation loss particularly in higher-order networks specialized for cognition.

Abstract

Healthy aging is accompanied by disruptions in the functional modular organization of the human brain. Cross-sectional studies have shown age-related reductions in the functional segregation and distinctiveness of brain networks. However, less is known about the longitudinal changes in brain functional modular organization and their associations with aging-related cognitive decline. We examined age- and aging-related changes in functional architecture of the cerebral cortex using a dataset comprising a cross-sectional healthy young cohort of 57 individuals (mean ± SD age, 23.71 ± 3.61 years, 22 males) and a longitudinal healthy elderly cohort of 72 individuals (mean ± baseline age, 68.22 ± 5.80 years, 39 males) with 2–3 time points (18–24 months apart) of task-free fMRI data. We found both cross-sectional (elderly vs young) and longitudinal (in elderly) global decreases in network segregation (decreased local efficiency), integration (decreased global efficiency), and module distinctiveness (increased participation coefficient and decreased system segregation). At the modular level, whereas cross-sectional analyses revealed higher participation coefficient across all modules in the elderly compared with young participants, longitudinal analyses revealed focal longitudinal participation coefficient increases in three higher-order cognitive modules: control network, default mode network, and salience/ventral attention network. Cross-sectionally, elderly participants also showed worse attention performance with lower local efficiency and higher mean participation coefficient, and worse global cognitive performance with higher participation coefficient in the dorsal attention/control network. These findings suggest that healthy aging is associated with whole-brain connectome-wide changes in the functional modular organization of the brain, accompanied by loss of functional segregation, particularly in higher-order cognitive networks.

A review on transcutaneous vagal nerve stimulation.

Colzato and Beste review the literature on cognitive effects of transcutaneous vagus nerve stimulation (tVNS), with a focus on studies on normal subjects suggesting that it might enhance memory and sharpen task relevant representations. I pass on a few clips from their text and also their abstract. Motivated readers can obtain the whole article by emailing me.

The focus of the present review article is not on clinical populations but on healthy humans and how especially auricular tVNS may be a useful neuromodulatory tool in cognitive neuroscience.

Only after commercially available auricular tVNS (NEMOS®) and cervical tVNS (gammaCore®) devices hit the market in the last few years, the idea of using tVNS as a tool for neuromodulation in cognitive neuroscience has been put forward.

Auricular tVNS is applied through a special earplug electrode to the outer ear, sending electrical impulses to the auricular branch of the vagus nerve, also called Alderman's nerve or Arnold's nerve. By doing so, the afferent (i.e., the thick-myelinated Aβ) fibers of Arnold's nerve are excited and the afferent signal propagates from peripheral nerves to nuclei in the brainstem, such as the locus coeruleus (LC) and the NST, and, ultimately, to intracranial subcortical (hippocampus) and cortical structures such as the insula, the prefrontal cortex (PFC) and the motor cortex. To date, auricular tVNS is applied to the left ear because of cardiac safety concerns, even 310 though, recently, these concerns have been challenged.

To date, most tVNS studies use commercially available stimulation devices. Usually, these are equipped with the following fixed parameters: frequency of 25 Hz, 200 μs pulse width, 30s on / 30s off-cycle, and current intensities up to 3 mA. Findings from animal studies, can thus not directly be transferred to study protocols in humans, since stimulation parameters can vary.

The reviewed literature indicates that the modulation of activation in the locus coeruleus and in th hippocampus and related NA release could be regarded as a possible working mechanism for the memory-enhancing effects of tVNS. Second, that increased cortical inhibition in the motor cortex and PFC due to high GABA levels in response to tVNS can facilitate response selection and inhibition processes via sharpening task-relevant representations and inhibiting competing responses.

Here is their abstract:

Brain stimulation approaches are important to gain causal mechanistic insights into the relevance of functional brain regions and/or neurophysiological systems for human cognitive functions. In recent years, transcutaneous vagus nerve stimulation (tVNS) has attracted considerable popularity. It is a noninvasive brain stimulation technique based on the stimulation of the vagus nerve. The stimulation of this nerve activates subcortical nuclei, such as the locus coeruleus and the nucleus of the solitary tract, and from there, the activation propagates to the cortex. Since tVNS is a novel stimulation technique, this literature review outlines a brief historical background of tVNS, before detailing underlying neurophysiological mechanisms of action, stimulation parameters, cognitive effects of tVNS on healthy humans, and, lastly, current challenges and future directions of tVNS research in cognitive functions. Although more research is needed, we conclude that tVNS, by increasing noradrenaline (NA) and gamma-aminobutyric acid (GABA) levels, affects NA and GABA-related cognitive performance. The review provides detailed background information how to use tVNS as a neuromodulatory tool in cognitive neuroscience and outlines important future leads of research on tVNS.

Effects of social media on well-being.

Allcott et al. do a fascinating study examining the effects of getting a random sample of Facebook users to deactivate their accounts for 4 weeks in exchange for $102.

The rise of social media has provoked both optimism about potential societal benefits and concern about harms such as addiction, depression, and political polarization. In a randomized experiment, we find that deactivating Facebook for the four weeks before the 2018 US midterm election (i) reduced online activity, while increasing offline activities such as watching TV alone and socializing with family and friends; (ii) reduced both factual news knowledge and political polarization; (iii) increased subjective well-being; and (iv) caused a large persistent reduction in post-experiment Facebook use. Deactivation reduced post-experiment valuations of Facebook, suggesting that traditional metrics may overstate consumer surplus.

Differential fertility makes society more conservative on family values

From Vogl and Freese:  

Significance

“Family values” conservatives in the United States have more children and more siblings than their compatriots. These patterns reflect the tendency of the more religious and less educated to have larger families and more conservative views on the family. Among Protestants, denominational differences play a role, with fundamentalist groups exhibiting larger families, less education, and greater conservatism. The causal pathways are unclear, but the patterns reshape society: Traditional-family conservatism is more prevalent than it would have been if each person had the same population share as his or her parents. This demographic phenomenon raises opposition to same-sex marriage and abortion by 3 to 4 percentage points. It accounts for 7.9 million of the nation’s 54.8 million opponents to same-sex marriage.

Abstract

Data from the General Social Survey indicate that higher-fertility individuals and their children are more conservative on “family values” issues, especially regarding abortion and same-sex marriage. This pattern implies that differential fertility has increased and will continue to increase public support for conservative policies on these issues. The association of family size with conservatism is specific to traditional-family issues and can be attributed in large part to the greater religiosity and lower educational attainment of individuals from larger families. Over the 2004 to 2018 period, opposition to same-sex marriage and abortion was 3 to 4 percentage points more prevalent than it would have been were traditional-family conservatism independent of family size in the current generation. For same-sex marriage, evolutionary forces have grown in relative importance as society as a whole has liberalized. As of 2018, differential fertility raised the number of US adults opposed to same-sex marriage by 17%, from 46.9 million to 54.8 million.

Older adults proactively downregulate anticipated negative affect.

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

Previous studies have only investigated age-related differences in emotional processing and encoding in response to, not in anticipation of, emotional stimuli. In the current study, we investigated age-related differences in the impact of emotional anticipation on affective responses and episodic memory for emotional images. Young and older adults were scanned while encoding negative and neutral images preceded by cues that were either valid or invalid predictors of image valence. Participants were asked to rate the emotional intensity of the images and to complete a recognition task. Using multivariate behavioral partial least squares (PLS) analysis, we found that greater anticipatory recruitment of the amygdala, ventromedial prefrontal cortex (vmPFC), and hippocampus in older adults predicted reduced memory for negative than neutral images and the opposite for young adults. Seed PLS analysis further showed that following negative cues older adults, but not young adults, exhibited greater activation of vmPFC, reduced activation of amygdala, and worse memory for negative compared with neutral images. To the best of our knowledge, this is the first study to provide evidence that the “positivity effect” seen in older adults’ memory performance may be related to the spontaneous emotional suppression of negative affect in anticipation of, not just in response to, negative stimuli.

Looking at pictures makes your brain’s visual cortex swell!

Wow, talk about dynamic neuroplasticity...Mansson et al (open source) take observations of how rapidly our brains can change to a whole new level. They show that our visual cortex gets bigger when viewing a picture versus a simple fixation cross.

Measuring brain morphology with non-invasive structural magnetic resonance imaging is common practice, and can be used to investigate neuroplasticity. Brain morphology changes have been reported over the course of weeks, days, and hours in both animals and humans. If such short-term changes occur even faster, rapid morphological changes while being scanned could have important implications. In a randomized within-subject study on 47 healthy individuals, two high-resolution T1-weighted anatomical images were acquired (á 263 s) per individual. The images were acquired during passive viewing of pictures or a fixation cross. Two common pipelines for analyzing brain images were used: voxel-based morphometry on gray matter (GM) volume and surface-based cortical thickness. We found that the measures of both GM volume and cortical thickness showed increases in the visual cortex while viewing pictures relative to a fixation cross. The increase was distributed across the two hemispheres and significant at a corrected level. Thus, brain morphology enlargements were detected in less than 263 s. Neuroplasticity is a far more dynamic process than previously shown, suggesting that individuals’ current mental state affects indices of brain morphology. This needs to be taken into account in future morphology studies and in everyday clinical practice.

Progress toward gender equality in the United States has slowed or stalled

From England et al.:

Significance

Social scientists have documented dramatic change in gender inequality in the last half century, sometimes called a “gender revolution.” We show dramatic progress in movement toward gender equality between 1970 and 2018, but also that in recent decades, change has slowed or stalled. The slowdown on some indicators and stall on others suggests that further progress requires substantial institutional and cultural change. Progress may require increases in men’s participation in household and care work, governmental provision of child care, and adoption by employers of policies that reduce gender discrimination and help both men and women combine jobs with family care responsibilities.

Abstract

We examine change in multiple indicators of gender inequality for the period of 1970 to 2018. The percentage of women (age 25 to 54) who are employed rose continuously until ∼2000 when it reached its highest point to date of 75%; it was slightly lower at 73% in 2018. Women have surpassed men in receipt of baccalaureate and doctoral degrees. The degree of segregation of fields of study declined dramatically in the 1970s and 1980s, but little since then. The desegregation of occupations continues but has slowed its pace. Examining the hourly pay of those aged 25 to 54 who are employed full-time, we found that the ratio of women’s to men’s pay increased from 0.61 to 0.83 between 1970 and 2018, rising especially fast in the 1980s, but much slower since 1990. In sum, there has been dramatic progress in movement toward gender equality, but, in recent decades, change has slowed and on some indicators stalled entirely.

Gender differences in the brain connections that predict intelligence.

From Jiang et al:

Scores on intelligence tests are strongly predictive of various important life outcomes. However, the gender discrepancy on intelligence quotient (IQ) prediction using brain imaging variables has not been studied. To this aim, we predicted individual IQ scores for males and females separately using whole-brain functional connectivity (FC). Robust predictions of intellectual capabilities were achieved across three independent data sets (680 subjects) and two intelligence measurements (IQ and fluid intelligence) using the same model within each gender. Interestingly, we found that intelligence of males and females were underpinned by different neurobiological correlates, which are consistent with their respective superiority in cognitive domains (visuospatial vs verbal ability). In addition, the identified FC patterns are uniquely predictive on IQ and its sub-domain scores only within the same gender but neither for the opposite gender nor on the IQ-irrelevant measures such as temperament traits. Moreover, females exhibit significantly higher IQ predictability than males in the discovery cohort. This findings facilitate our understanding of the biological basis of intelligence by demonstrating that intelligence is underpinned by a variety of complex neural mechanisms that engage an interacting network of regions—particularly prefrontal–parietal and basal ganglia—whereas the network pattern differs between genders.

Arthur Brooks launches a happiness column.

It seems a bit strange to launch a column on happiness during a pandemic, but the social isolation that has been forced on us provides us with more time to consider our lives and what really has meaning for us. Arthur Brooks, who teaches a class at the Harvard Business School on happiness, has now offered what is the first in a series of articles in The Atlantic on identifying the building blocks of subjective well-being. (The term well-being is preferred to happiness, because happiness is used to denote everything from a passing good mood to a deeper sense of meaning in life.) I recommend that you read Brooks' article, and pass on here edited chunks of text with three succinct equations he offers for well-being, equations having some variables you can have some influence over, and others that you can not easily change.  

Equation 1: Subjective Well-being = Genes + Circumstances + Habits

Studies of identical twins raised apart suggest that the genetic component of a person’s well-being is between 44 percent and 52 percent, that is, about half. Circumstances—the good and the bad that enter all of our lives—could make up as little as 10 percent or as much as 40 percent of your subjective well-being. Even if circumstances play a big role, however, most scholars think it doesn’t matter very much, because the effects of circumstance never last very long. Genes and circumstances aren’t a productive focus in your quest for happiness. But don’t worry, there’s one variable left that affects long-term well-being and is under our control: habits. To understand habits, we need Equation 2.

Equation 2: Habits = Faith + Family + Friends + Work

Enduring happiness comes from human relationships, productive work, and the transcendental elements of life...many different faiths and secular life philosophies can provide this happiness edge. The key is to find a structure through which you can ponder life’s deeper questions and transcend a focus on your narrow self-interests to serve others...Similarly, there is no magic formula for what shape your family and friendships should take.People who have loving relationships with family and friends thrive; those who don’t, don’t...One of the most robust findings in the happiness literature is the centrality of productive human endeavor in creating a sense of purpose in life...What makes work meaningful is not the kind of work it is, but the sense it gives you that you are earning your success and serving others.

Equation 3: Satisfaction = What you have ÷ What you want

The secret to satisfaction is to focus on the denominator of Equation 3. Don’t obsess about your haves; manage your wants, instead. Don’t count your possessions (or your money, power, prestige, romantic partners, or fame) and try to figure out how to increase them; make an inventory of your worldly desires and try to decrease them. Make a bucket list—but not of exotic vacations and expensive stuff. Make a list of the attachments in your life you need to discard. Then, make a plan to do just that. The fewer wants there are screaming inside your brain and dividing your attention, the more peace and satisfaction will be left for what you already have.

After offering the above three equations as the first class in the mechanics of building a life, Brooks promises in the coming months to offer further installments on the art and science of happiness.

By the way, since this is a post on the subject of happiness,  I want to also point to a recent Sam Harris podcast on the science of happiness - a conversation with Laurie Santos, who  teaches the most popular course offered at Yale, "The Science of WellBeing," and also hosts the popular podcast The Happiness Lab.

Two sources on the state of America

Like many MindBlog readers, I am reading countless articles on the current pandemic and its medical, economic, and social consequences. I generally restrain myself from noting them on MindBlog, worrying that readers have become as saturated as I have. However, I do want to point to two that do stand out:

First, In a Making Sense Podcast Sam Harris talks with General Stanley McChrystal and Chris Fussell about the Covid-19 pandemic. They discuss the nature of the ongoing crisis, the threat of a breakdown in social order, the problem of misinformation, the prospects of a nationwide lockdown, the trade off between personal freedom and safety, the threat of tyranny, the concerns about the global supply chain, concerns about the price of oil, safeguarding the 2020 Presidential election, and other topics. McChrystal was the commander of all American and coalition forces in Afghanistan, is now senior fellow at Yale University’s Jackson Institute for Global Affairs, and is founder of the McChrystal Group leadership institute.

Second, a piece by Leonhardt and Serkez in the New York Times opinion series “The America We Need” paints the most clear graphical picture I have seen of how inequality in America has grown to its current extreme, defining the struggle society faces after Coronavirus.