You ideal job can be predicted by your social media behavior.

So...are occupational guidance counselors going to be replaced by social media algorithms? From Kern et al.: 

Significance

Employment is thought to be more enjoyable and beneficial to individuals and society when there is alignment between the person and the occupation, but a key question is how to best match people with the right profession. The information that people broadcast online through social media provides insights into who they are, which we show can be used to match people and occupations. Findings have implications for career guidance for new graduates, disengaged employees, career changers, and the unemployed.

Abstract

Work is thought to be more enjoyable and beneficial to individuals and society when there is congruence between one’s personality and one’s occupation. We provide large-scale evidence that occupations have distinctive psychological profiles, which can successfully be predicted from linguistic information unobtrusively collected through social media. Based on 128,279 Twitter users representing 3,513 occupations, we automatically assess user personalities and visually map the personality profiles of different professions. Similar occupations cluster together, pointing to specific sets of jobs that one might be well suited for. Observations that contradict existing classifications may point to emerging occupations relevant to the 21st century workplace. Findings illustrate how social media can be used to match people to their ideal occupation.

An alternative neural mechanism for treating anxiety disorders through safety signal learning.

In these times of political polarization all over the world, over one third of all people experience anxiety disorders, in which circumstances frequently are taken to be more threatening than they actually are. This makes understanding the inhibition of emotional over-reactivity an important goal of brain research. Meyer et al. make a significant contribution by identifying a pathway that engages the ventral hippocampus for the attenuation of threat responses through conditioned inhibition using neurons that are more active to safety and compound cues than threat cues. This pathway might be a target for therapeutic approaches. Their summaries:  

Significance

Although fear can contribute to survival, difficulty regulating threat responses can interfere with goal-directed activities and is the hallmark of anxiety disorders. These disorders are the most common psychiatric illnesses, affecting up to one-third of the population. In parallel studies across species, we identify a pathway that engages the ventral hippocampus for the attenuation of threat responses through conditioned inhibition. Conditioned inhibition relies on the specific involvement of ventral hippocampal neurons projecting to the prelimbic cortex in mice and homologous ventral hippocampal–dorsal anterior cingulate cortex functional connectivity in humans. These findings highlight a pathway for the inhibition of fear with the potential to enhance interventions for anxiety disorders by targeting an alternative neural circuitry through safety signal learning.

Abstract

Heightened fear and inefficient safety learning are key features of fear and anxiety disorders. Evidence-based interventions for anxiety disorders, such as cognitive behavioral therapy, primarily rely on mechanisms of fear extinction. However, up to 50% of clinically anxious individuals do not respond to current evidence-based treatment, suggesting a critical need for new interventions based on alternative neurobiological pathways. Using parallel human and rodent conditioned inhibition paradigms alongside brain imaging methodologies, we investigated neural activity patterns in the ventral hippocampus in response to stimuli predictive of threat or safety and compound cues to test inhibition via safety in the presence of threat. Distinct hippocampal responses to threat, safety, and compound cues suggest that the ventral hippocampus is involved in conditioned inhibition in both mice and humans. Moreover, unique response patterns within target-differentiated subpopulations of ventral hippocampal neurons identify a circuit by which fear may be inhibited via safety. Specifically, ventral hippocampal neurons projecting to the prelimbic cortex, but not to the infralimbic cortex or basolateral amygdala, were more active to safety and compound cues than threat cues, and activity correlated with freezing behavior in rodents. A corresponding distinction was observed in humans: hippocampal–dorsal anterior cingulate cortex functional connectivity—but not hippocampal–anterior ventromedial prefrontal cortex or hippocampal–basolateral amygdala connectivity—differentiated between threat, safety, and compound conditions. These findings highlight the potential to enhance treatment for anxiety disorders by targeting an alternative neural mechanism through safety signal learning.

Great graphics - a review of cerebral cortex structure/folding from mice to humans.

I pass on this open source review article for the small number of MindBlog readers who might find it useful in their teaching. The summary color graphics of increasingly larger vertebrate brains (Mouse, Marmosett, Macaque, Chimpanzee, Human) show overall appearance and cell number, myelin patterns, and cortical parcellations. Here is the technical abstract:

Advances in neuroimaging and neuroanatomy have yielded major insights concerning fundamental principles of cortical organization and evolution, thus speaking to how well different species serve as models for human brain function in health and disease. Here, we focus on cortical folding, parcellation, and connectivity in mice, marmosets, macaques, and humans. Cortical folding patterns vary dramatically across species, and individual variability in cortical folding increases with cortical surface area. Such issues are best analyzed using surface-based approaches that respect the topology of the cortical sheet. Many aspects of cortical organization can be revealed using 1 type of information (modality) at a time, such as maps of cortical myelin content. However, accurate delineation of the entire mosaic of cortical areas requires a multimodal approach using information about function, architecture, connectivity, and topographic organization. Comparisons across the 4 aforementioned species reveal dramatic differences in the total number and arrangement of cortical areas, particularly between rodents and primates. Hemispheric variability and bilateral asymmetry are most pronounced in humans, which we evaluated using a high-quality multimodal parcellation of hundreds of individuals. Asymmetries include modest differences in areal size but not in areal identity. Analyses of cortical connectivity using anatomical tracers reveal highly distributed connectivity and a wide range of connection weights in monkeys and mice; indirect measures using functional MRI suggest a similar pattern in humans. Altogether, a multifaceted but integrated approach to exploring cortical organization in primate and nonprimate species provides complementary advantages and perspectives.

Brain aging reduced by elevating acetyl-CoA levels.

Acetyl coenzyme A (acetyl-CoA) is a central molecule in the energy metabolism of mitochondria in our cells. Currais et al. show that two Alzheimer's disease (AD) drug candidates known to reduce cognitive decline in a mouse model of AD increase acetyl-CoA levels and preserve mitochondrial function. Here is their technical abstract:

Because old age is the greatest risk factor for dementia, a successful therapy will require an understanding of the physiological changes that occur in the brain with aging. Here, two structurally distinct Alzheimer's disease (AD) drug candidates, CMS121 and J147, were used to identify a unique molecular pathway that is shared between the aging brain and AD. CMS121 and J147 reduced cognitive decline as well as metabolic and transcriptional markers of aging in the brain when administered to rapidly aging SAMP8 mice. Both compounds preserved mitochondrial homeostasis by regulating acetyl-coenzyme A (acetyl-CoA) metabolism. CMS121 and J147 increased the levels of acetyl-CoA in cell culture and mice via the inhibition of acetyl-CoA carboxylase 1 (ACC1), resulting in neuroprotection and increased acetylation of histone H3K9 in SAMP8 mice, a site linked to memory enhancement. These data show that targeting specific metabolic aspects of the aging brain could result in treatments for dementia.

The quiet brains of athletes

An interesting study by Kraus and collaborators shows that athletes have larger responses to specified sounds than non-athletes, due to a reduction in their level of background neural noise. Their brains are not as noisy as those of non-athletes. From their abstract:

Playing sports has many benefits, including boosting physical, cardiovascular, and mental fitness. We tested whether athletic benefits extend to sensory processing—specifically auditory processing—as measured by the frequency-following response (FFR), a scalp-recorded electrophysiological potential that captures neural activity predominately from the auditory midbrain to complex sounds...We measured FFRs to the speech syllable “da” in 495 student-athletes across 19 Division I teams and 493 age- and sex-matched controls and compared them on 3 measures of FFR amplitude: amplitude of the response, amplitude of the background noise, and the ratio of these 2 measures.

Athletes have larger responses to sound than nonathletes, driven by a reduction in their level of background neural noise...These findings suggest that playing sports increases the gain of an auditory signal by turning down the background noise. This mode of enhancement may be tied to the overall fitness level of athletes and/or the heightened need of an athlete to engage with and respond to auditory stimuli during competition.

Such a study cannot distinguish whether being an athlete changed the young people’s brains or whether they succeeded as athletes because they were better at sound processing from the start. Further work might resolve this, as well as determining whether older people can reshape their sound processing by becoming active.

Anti-immigration sentiment does not correlate with local democraphic changes.

Hill et al. analyze election results and demographic measures for almost 32,000 precincts in the states of Florida, Georgia, Michigan, Nevada, Ohio, Pennsylvania, and Washington. Influxes of non-citizen immigrants correlated with vote shift away from the anti-immigration candidate (Trump) in the 2016 election. A commentary by Enos notes, however that:

....If ethnic minority populations are segregated and those voters without day-to-day contact continue to react negatively against the minority group, then even a local positive correlation between diversity and liberal politics may not lead to long-term harmony for a society...if increasing diversity affects political outcomes, the relationship can point in two consequentially different directions: toward increased diversity liberalizing politics or toward increased diversity causing a reactionary backlash.

From Hill et al.:

Significance

In recent years, advanced industrial democracies have grown more ethnically and racially diverse. This increasing diversity has the potential to reshape voting behavior in those countries, in part because majority groups may react by shifting support toward anti-immigration candidates and parties. This paper considers whether local demographic changes in the United States were associated with pro-Republican shifts between 2012 and 2016, when the Republican presidential candidate was especially outspoken in opposition to immigration. By showing that demographic changes were not associated with shifts toward the Republican, this research indicates that local demographic changes are not on their own increasing support for anti-immigration candidates.

Abstract

Immigration and demographic change have become highly salient in American politics, partly because of the 2016 campaign of Donald Trump. Previous research indicates that local influxes of immigrants or unfamiliar ethnic groups can generate threatened responses, but has either focused on nonelectoral outcomes or analyzed elections in large geographic units, such as counties. Here, we examine whether demographic changes at low levels of aggregation were associated with vote shifts toward an anti-immigration presidential candidate between 2012 and 2016. To do so, we compile a precinct-level dataset of election results and demographic measures for almost 32,000 precincts in the states of Florida, Georgia, Michigan, Nevada, Ohio, Pennsylvania, and Washington. We employ regression analyses varying model specifications and measures of demographic change. Our estimates uncover little evidence that influxes of Hispanics or noncitizen immigrants benefited Trump relative to past Republicans, instead consistently showing that such changes were associated with shifts to Trump’s opponent.

Increased emotional reactivity in men with high hair testosterone concentrations.

As I was scanning the table of contents of the latest issue of the journal "Social Cognitive and Affective Neuroscience" the article whose abstract I pass on below jumped out at me. (This is because I feel more emotional and sexual when my androgen levels reach their highest point in a monthly cycle, with lower points in the cycle correlating with lower motivation and anhedonia.) From Klein et al.:

Testosterone has been linked to alterations in the activity of emotion neurocircuitry including amygdala, orbitofrontal cortex (OFC) and insula and diminished functional amygdala/prefrontal coupling. Such associations have only ever been studied using acute measures of testosterone, thus little is known about respective relationships with long-term testosterone secretion. Here, we examine associations between hair testosterone concentration (HTC), an index of long-term cumulative testosterone levels and neural reactivity during an emotional passive viewing task using functional magnetic resonance imaging (fMRI). Forty-six men viewed negative, positive and neutral pictures in the MRI. HTCs were assessed from 2 cm hair segments. The emotional paradigm elicited neural activation in the amygdala, insula and OFC. HTCs were associated with increased reactivity to negative pictures in the insula and increased reactivity to positive pictures in the OFC. We show an association of long-term testosterone levels with increased emotional reactivity in the brain. These results suggest a heightened emotional vigilance in individuals with high trait testosterone levels.

We’ve just had the best decade (and year) in human history. Seriously

To provide a faintly upbeat end of the year post, I want to point to a Matt Ridley piece in The Spectator that provides a bit of a tonic for our times, by pointing out facts that haven't made the news, because good news is no news. Bad things capture our attention while the world overall is still getting better. In the same vein, Nicholas Kristof does a NYTimes piece titled "This Has Been the Best Year Ever" which has some nice graphics describing amazing declines in poverty and infant deaths, and gains in literacy. Some clips from the Ridley piece:

Extreme poverty has fallen below 10 per cent of the world’s population for the first time...Global inequality has been plunging as Africa and Asia experience faster economic growth than Europe and North America; child mortality has fallen to record low levels; famine virtually went extinct; malaria, polio and heart disease are all in decline.

...we are getting more sustainable, not less, in the way we use the planet...some nations are beginning to use less stuff: less metal, less water, less land. Not just in proportion to productivity: less stuff overall...what if economic growth means using less stuff, not more?’ For example, a normal drink can today contains 13 grams of aluminium, much of it recycled. In 1959, it contained 85 grams. Substituting the former for the latter is a contribution to economic growth, but it reduces the resources consumed per drink...The quantity of all resources consumed per person in Britain (domestic extraction of biomass, metals, minerals and fossil fuels, plus imports minus exports) fell by a third between 2000 and 2017, from 12.5 tonnes to 8.5 tonnes. That’s a faster decline than the increase in the number of people, so it means fewer resources consumed overall.

Mobile phones have the computing power of room-sized computers of the 1970s. I use mine instead of a camera, radio, torch, compass, map, calendar, watch, CD player, newspaper and pack of cards. LED light bulbs consume about a quarter as much electricity as incandescent bulbs for the same light...Even in cases when the use of stuff is not falling, it is rising more slowly than expected. For instance, experts in the 1970s forecast how much water the world would consume in the year 2000. In fact, the total usage that year was half as much as predicted. Not because there were fewer humans, but because human inventiveness allowed more efficient irrigation for agriculture, the biggest user of water.

...despite the growing number of people and their demand for more and better food, the productivity of agriculture is rising so fast that human needs can be supplied by a shrinking amount of land...we use 65 per cent less land to produce a given quantity of food compared with 50 years ago. By 2050, it’s estimated that an area the size of India will have been released from the plough and the cow.

Since its inception, the environmental movement has been obsessed by finite resources. The two books that kicked off the green industry in the early 1970s, The Limits to Growth in America and Blueprint for Survival in Britain, both lamented the imminent exhaustion of metals, minerals and fuels. The Limits to Growth predicted that if growth continued, the world would run out of gold, mercury, silver, tin, zinc, copper and lead well before 2000...To this day none of those metals has significantly risen in price or fallen in volume of reserves, let alone run out.

A modern irony is that many green policies advocated now would actually reverse the trend towards using less stuff. A wind farm requires far more concrete and steel than an equivalent system based on gas. Environmental opposition to nuclear power has hindered the generating system that needs the least land, least fuel and least steel or concrete per megawatt.

As we enter the third decade of this century, I’ll make a prediction: by the end of it, we will see less poverty, less child mortality, less land devoted to agriculture in the world. There will be more tigers, whales, forests and nature reserves. Britons will be richer, and each of us will use fewer resources. The global political future may be uncertain, but the environmental and technological trends are pretty clear — and pointing in the right direction.

World in decline? New authoritarian age? - the dangers of declinism.

These are times of high anxiety for both Red and Blue state America. A powerful Op-Ed by Roger Cohen, in the wake of the British election, sees a coming Trump victory in 2010, and David Brooks suggests that voters will pick whichever candidate exhausts them less. Numerous articles outline an emerging world of authoritarian surveillance states that fail to engage the looming disaster of global warming.

Jeremy Adelman, director of the Global History Lab at Princeton University, offers an interesting essay, noting that the idea of decline is one thing the extremes of Left and Right agree upon. Adelman reviews the history of declinism, and describes the fate of several previous dire predictions about humanity's future that did not come to pass, from Malthus' 18th century essay to The Club of Rome's "The Limits to Growth of 1972.  (For a recent rebuttal of declinism, see Matt Ridley's essay in The Spectator: "We've just had the best decade in human history. Seriously.")

Here are some clips from Adelman's piece:

Declinisms share some traits. They have more purchase in times of turmoil and uncertainty. They are also prone to thinking that the circles of hell can be avoided only with a great catharsis or a great charismatic figure.

But most of all: they ignore signs of improvement that point to less drastic ways out of trouble. Declinists have a big blindspot because they are attracted to daring, total, all-encompassing alternatives to the humdrum greyness of modest solutions. Why go for partial and piecemeal when you can overturn the whole system?

One dissenting voice in the 1970s was Albert O Hirschman’s. He worried about the lure of doomsaying. Dire predictions, he warned, can blind big-picture observers to countervailing forces, positive stories and glimmers of solutions. There is a reason why: declinists confuse the growing pains of change with signs of the end of entire systems. Declinism misses the possibility that behind the downsizing old ways there might be new ones poking through.

Why the allure of declinism if history seldom conforms to the predictions? To Hirschman, it was traceable to a prophetic style, one that appealed to intellectuals drawn to ‘fundamentalist’ explanations and who preferred to point to intractable causes of social problems. For revolutionaries, what awaits is a utopian alternative. For reactionaries, what lies in wait is dystopia. The result is an ‘antagonistic’ mode of thinking, a belief that history swings from one big, integrated, all-encompassing system to another. Compared with modest advances, compromises and concessions – how boring! – the magnificent vision of a complete overhaul has so many charms.

The problem with declinism is that it confirms the virtues of our highest, impossible solutions to fundamental problems. It also confirms the disappointments we harbour in the changes we have actually made. This is not to say there aren’t deep-seated problems. But seeing them as evidence of ineluctable demise can impoverish our imaginations by luring us to the sirens of either total change or fatalism.

For the holiday season - the gift of self care

To acknowledge that today is a special one for a large fraction of humanity, I want to pass on Parker-Pope's description of suggestions by Korean Buddhist teacher Haemin Sunim - five simple steps to quiet the mind and soothe stress at any time of the year, all in the spirit of "be good to yourself first - then to others."

Breathe

Start by just taking a deep breath. Become mindful of your breathing. You’ll notice that when you begin, your breathing is shorter and more shallow, but as you continue, your breathing becomes deeper. Take just a few minutes each day to focus on your breathing. “As my breathing becomes much deeper and I’m paying attention to it, I feel much more centered and calm,” Haemin Sunim said. “I feel I can manage whatever is happening right now.”

Accept

Acceptance — of ourselves, our feelings and of life’s imperfections — is a common theme in “Love for Imperfect Things.” The path to self-care starts with acceptance, especially of our struggles. “If we accept the struggling self, our state of mind will soon undergo a change,” Haemin Sunim writes. “When we regard our difficult emotions as a problem and try to overcome them, we only struggle more. In contrast, when we accept them, strangely enough our mind stops struggling and suddenly grows quiet. Rather than trying to change or control difficult emotions from the inside, allow them to be there, and your mind will rest.”

Write

Begin to practice acceptance through a simple writing exercise. Write down the situation you must accept and all that you are feeling. Write down the things in your life that are weighing on you'''the goal is to leave it all on the paper. Now go to bed and when you wake up, choose the easiest task on the list to complete. “In the morning, rather than resisting, I will simply do the easiest thing I can do from the list,” Haemin Sunim said. “Once I finish the easiest task, it’s much easier to work on the second.”

Talk

Never underestimate the value of meaningful conversation for your well-being. Make time on a regular basis for a close, nonjudgmental friend...Choose someone who will listen without any kind of judgment...Once the story is released, you can see it more objectively, and you will know what it is you need to do.”

Walk

One of the easiest ways to care for yourself is to take a walk. Just walking...can distract your mind and create space between you and whatever is causing stress in your life... If you start walking, our physical energy changes and rather than dwelling on that story, you can pay attention to nature — a tree trunk, a rock. You begin to see things more objectively, and oftentimes that stress within your body will be released simply by walking.”

Is this what my grandson will be doing in a few years?

My seven year old grandson Sebastian is a performer, taking piano lessons and reminding me a bit of myself when I was doing the same thing at his age. I think the tenuous similarity in our experiences will soon evaporate, especially in a few years if he joins the world of YouTube "Creators." The following YouTube summary of most popular videos of 2019 lets me (the 77 year old retired professor) know I am living on Mars.

Setting back our epigenic age?

I would like to point to Josh Mitteldorf's Blog "Aging Matters", in particular "Pulsed Yamanaka Factors Set Back Epigenic Age." A clip:

There’s a preprint from David Sinclair’s Harvard laboratory, posted on BioRxiv but not yet published, with very encouraging news for those of us who think that resetting the epigenetic (methylation) clock is a path to anti-aging. They suggest that 3 of the 4 Yamanaka factors, administered in short pulses, can set back the Horvath methylation clock without turning functioning tissues back into stem cells. The same study offers evidence to support the hypothesis that the epigenetic clock is a lethal driver of aging, rather than an adaptive response to damage.

MindBlog reviews the HealthyMinds App

The Center for Healthy Minds at the University of Wisconsin, established by my former University of Wisconsin colleague Richard Davidson, is trying to export the results of its basic research into practical forms - workplace programs, school programs, and now an App for tablets or cell phones.

I've put the App on my iPhone, and want to report my experience of going through its sequence of mini-lectures and exercises, organized under five categories: Foundations, awareness, connection, insight, and purpose. The basic science presented and the exercises were familiar to me, and I was struck by how effectively the essence of each was presented in its most simple and accessible form. (I would have liked to have been able to see the brief voice lectures also offered in text form.) For example, the instruction most often seen for the exercise of paying attention to breathing suggest counting each breath, from one to nine or ten, then repeating, and returning to this practice when one notices having been distracted by other thoughts.  Why not just count to three, as instructed by the App.  It is more simple, and equally effective.  For each of the exercises, one can choose a sitting or active version (active meaning doing routine, but not novel, activities),  a male or female narrator, and varying duration from 5 to 30 min.  It was not until I had finished the available series of lectures and exercises and tried to go back to earlier stages and examine them in more detail that I encountered a requirement that a subscription be purchased (~$5/month, but see below).   If the ideas and exercises presented were less familiar to me, and I was not already fairly settled in my various practices, I'm sure I would purchase a subscription to the App.

(added note: Please see the comment below.  A subscription is not required to repeat the Foundations section I was describing. It is  offered for further engagement of the Awareness, Connection, Insight, and Purpose modules.) 

Favorite sentences

I have to pass on a few of the favorite sentences collected by book critic Dwight Garner from his 2019 list of books - you can get the citations from the article.

“Watch for the glamorous sentence that appears from nowhere — it might have plans for you.”

“If you don’t know the exact moment when the lights will go out, you might as well read until they do.”

“The one good thing about national anthems is that we’re already on our feet, and therefore ready to run.”

“How’re you doing,” a character asked in Ali Smith’s novel “Spring,” “apart from the end of liberal capitalist democracy?”

“Take a simpleton and give him power and confront him with intelligence — and you have a tyrant.”

In Robert Menasse’s sophisticated novel “The Capital,” set in Brussels, a character watched old nationalist ghosts rise in a tabloid culture, and commented: “He had been prepared for everything, but not everything in caricature.”...also from this novel...“Back in 1914, his grandfather had said, Brussels was the richest and most beautiful city in the world — then they came three times, twice in their boots with rifles, the third time in their trainers with cameras.”

Or, to let it all pass by...

Nabokov told an interviewer in 1974, “I don’t even know who Mr. Watergate is.”

And, I will add a favorite sentence of my own, from Pinker’s guide to writing “Sense of Style..”

"The key to good style, far more than obeying any list of commandments, is to have a clear conception of the make-believe world in which you’re pretending to communicate."

Our blood protein profiles change in the fourth, seventh and eighth decades of life

Lehallier et al. find that ~1,380 of the ~3,000 plasma proteins in blood samples from 4,263 people between the ages of 18 and 95 vary significantly with age, with big shifts occurring around the ages of 34, 60, and 78 - in the fourth, seventh and eighth decades of life:

Aging is a predominant risk factor for several chronic diseases that limit healthspan. Mechanisms of aging are thus increasingly recognized as potential therapeutic targets. Blood from young mice reverses aspects of aging and disease across multiple tissues, which supports a hypothesis that age-related molecular changes in blood could provide new insights into age-related disease biology. We measured 2,925 plasma proteins from 4,263 young adults to nonagenarians (18–95 years old) and developed a new bioinformatics approach that uncovered marked non-linear alterations in the human plasma proteome with age. Waves of changes in the proteome in the fourth, seventh and eighth decades of life reflected distinct biological pathways and revealed differential associations with the genome and proteome of age-related diseases and phenotypic traits. This new approach to the study of aging led to the identification of unexpected signatures and pathways that might offer potential targets for age-related diseases.

Our visual system uses recurrence in its representational dynamics

Fundamental work from Kietzmann et al. shows how recurrence - lateral and top-down feedback from higher to the more primary visual areas of the brain that first register visual input - is occurring during forming visual representations. This process is missing from engineering and neuroscience models that emphasize feedforward neural network models. (Click the link to the article and scroll down to see a fascinating video of their real time magnetoencephalography (MEG) measurements. ) 


Significance

Understanding the computational principles that underlie human vision is a key challenge for neuroscience and could help improve machine vision. Feedforward neural network models process their input through a deep cascade of computations. These models can recognize objects in images and explain aspects of human rapid recognition. However, the human brain contains recurrent connections within and between stages of the cascade, which are missing from the models that dominate both engineering and neuroscience. Here, we measure and model the dynamics of human brain activity during visual perception. We compare feedforward and recurrent neural network models and find that only recurrent models can account for the dynamic transformations of representations among multiple regions of visual cortex.

Abstract

The human visual system is an intricate network of brain regions that enables us to recognize the world around us. Despite its abundant lateral and feedback connections, object processing is commonly viewed and studied as a feedforward process. Here, we measure and model the rapid representational dynamics across multiple stages of the human ventral stream using time-resolved brain imaging and deep learning. We observe substantial representational transformations during the first 300 ms of processing within and across ventral-stream regions. Categorical divisions emerge in sequence, cascading forward and in reverse across regions, and Granger causality analysis suggests bidirectional information flow between regions. Finally, recurrent deep neural network models clearly outperform parameter-matched feedforward models in terms of their ability to capture the multiregion cortical dynamics. Targeted virtual cooling experiments on the recurrent deep network models further substantiate the importance of their lateral and top-down connections. These results establish that recurrent models are required to understand information processing in the human ventral stream.

More insight into metformin's beneficial effects on diabetes, aging, and several diseases.

A group at McMaster University has shown an effect of the diabetes drug metformin beyond its suppression of liver glucose production that might partially explain its beneficial effects on aging and a number of diverse diseases such as cognitive disorders, cancer and cardiovascular disease. (There are currently over 1,500 registered clinical trials to test the effects of metformin in aging and different diseases.) It induces the expression and secretion of growth differentiating factor 15 (GDF15) in mouse liver cells, a protein known to suppress appetite and cause weight loss.

I'm sorely tempted to try to get myself a prescription for the stuff! Here is the technical abstract of the article:

Metformin is the most commonly prescribed medication for type 2 diabetes, owing to its glucose-lowering effects, which are mediated through the suppression of hepatic glucose production (reviewed in refs. 1,2,3). However, in addition to its effects on the liver, metformin reduces appetite and in preclinical models exerts beneficial effects on ageing and a number of diverse diseases (for example, cognitive disorders, cancer, cardiovascular disease) through mechanisms that are not fully understood1,2,3. Given the high concentration of metformin in the liver and its many beneficial effects beyond glycemic control, we reasoned that metformin may increase the secretion of a hepatocyte-derived endocrine factor that communicates with the central nervous system4. Here we show, using unbiased transcriptomics of mouse hepatocytes and analysis of proteins in human serum, that metformin induces expression and secretion of growth differentiating factor 15 (GDF15). In primary mouse hepatocytes, metformin stimulates the secretion of GDF15 by increasing the expression of activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP; also known as DDIT3). In wild-type mice fed a high-fat diet, oral administration of metformin increases serum GDF15 and reduces food intake, body mass, fasting insulin and glucose intolerance; these effects are eliminated in GDF15 null mice. An increase in serum GDF15 is also associated with weight loss in patients with type 2 diabetes who take metformin. Although further studies will be required to determine the tissue source(s) of GDF15 produced in response to metformin in vivo, our data indicate that the therapeutic benefits of metformin on appetite, body mass and serum insulin depend on GDF15.

Heritable gaps between chronological age and brain age are increased in common brain disorders.

Kaufmann et al. have used machine learning on s large dataset to estimate robust estimation of individual biological brain ages on the basis of structural brain imaging features. The deviation between brain age and chronological age — termed the brain age gap — appears to be a promising marker of brain health. It was largest in schizophrenia, multiple sclerosis, dementia, and bipolar spectrum disorder. The authors also assessed the overlap between the genetic underpinnings of brain age gap and common brain disorders. The bottom line conclusion (from a very extensive and complex analysis) is that common brain disorders are associated with heritable patterns of apparent aging of the brain Their abstract:

Common risk factors for psychiatric and other brain disorders are likely to converge on biological pathways influencing the development and maintenance of brain structure and function across life. Using structural MRI data from 45,615 individuals aged 3–96 years, we demonstrate distinct patterns of apparent brain aging in several brain disorders and reveal genetic pleiotropy between apparent brain aging in healthy individuals and common brain disorders.

Same-Sex behavior in animals - a new view.

Monk et al. offer a fresh perspective on the "problem" of how same-sex sexual behavior could have evolved. It is a problem only if different-sex sexual behavior is the baseline condition for animals, from which single-sex behavior has evolved. The authors suggest that same-sex behavior is bound up in the very origins of animal sex. It hasn’t had to continually re-evolve: It’s always been there. The arguments of Monk and collaborators are summarized in a review by Elbein:

Instead of wondering why same-sex behavior had independently evolved in so many species, Ms. Monk and her colleagues suggest that it may have been present in the oldest parts of the animal family tree. The earliest sexually reproducing animals may have mated with any other individual they came across, regardless of sex. Such reproductive strategies are still practiced today by hermaphroditic species, like snails, and species that don’t appear to differentiate, like sea urchins.

Over time, Ms. Monk said, sexual signals evolved — different sizes, colors, anatomical features and behaviors — allowing different sexes to more accurately target each other for reproduction. But same-sex behavior continued in some organisms, leading to diverse sexual behaviors and strategies across the animal kingdom. And while same-sex behavior may grant some evolutionary benefits, an ancient origin would mean those benefits weren’t required for it to exist.

But how has same-sex behavior stuck around? The answer may be that such behaviors aren’t as evolutionarily costly as assumed. Traditionally, Ms. Monk said, any mating behavior that doesn’t produce young is seen as a waste. But animal behavior often doesn’t fit neatly into an economic accounting of costs and benefits.

Here is the abstract of Monk et al.:

Same-sex sexual behaviour (SSB) has been recorded in over 1,500 animal species with a widespread distribution across most major clades. Evolutionary biologists have long sought to uncover the adaptive origins of ‘homosexual behaviour’ in an attempt to resolve this apparent Darwinian paradox: how has SSB repeatedly evolved and persisted despite its presumed fitness costs? This question implicitly assumes that ‘heterosexual’ or exclusive different-sex sexual behaviour (DSB) is the baseline condition for animals, from which SSB has evolved. We question the idea that SSB necessarily presents an evolutionary conundrum, and suggest that the literature includes unchecked assumptions regarding the costs, benefits and origins of SSB. Instead, we offer an alternative null hypothesis for the evolutionary origin of SSB that, through a subtle shift in perspective, moves away from the expectation that the origin and maintenance of SSB is a problem in need of a solution. We argue that the frequently implicit assumption of DSB as ancestral has not been rigorously examined, and instead hypothesize an ancestral condition of indiscriminate sexual behaviours directed towards all sexes. By shifting the lens through which we study animal sexual behaviour, we can more fruitfully examine the evolutionary history of diverse sexual strategies.

Something in the way we move.

Gretchen Reynolds points to work by Hug et al. suggesting that each of us has a unique muscle activation signature that can be revealed during walking and pedaling. Understanding movement patterns could help in improving and refining robotics, prosthetics, physical therapy and personalized exercise programs. On the darker side, a Chinese company (Watrix) is using computer vision to to enhance the recognition of individuals in crowds by their walking postures:

...its gait recognition solution “Shuidi Shenjian” ... will enable security departments to quickly search and recognize identities by their body shape and walking posture. The company notes that this product is highly effective when targets walk from a long distance or in weak light, cover their faces or wear different clothes, and would be a great supplement to current computer vision products.

Here is the complete abstract from Hug et al.:

Although it is known that the muscle activation patterns used to produce even simple movements can vary between individuals, these differences have not been considered to prove the existence of individual muscle activation strategies (or signatures). We used a machine learning approach (support vector machine) to test the hypothesis that each individual has unique muscle activation signatures. Eighty participants performed a series of pedaling and gait tasks, and 53 of these participants performed a second experimental session on a subsequent day. Myoelectrical activity was measured from eight muscles: vastus lateralis and medialis, rectus femoris, gastrocnemius lateralis and medialis, soleus, tibialis anterior, and biceps femoris-long head. The classification task involved separating data into training and testing sets. For the within-day classification, each pedaling/gait cycle was tested using the classifier, which had been trained on the remaining cycles. For the between-day classification, each cycle from day 2 was tested using the classifier, which had been trained on the cycles from day 1. When considering all eight muscles, the activation profiles were assigned to the corresponding individuals with a classification rate of up to 99.28% (2,353/2,370 cycles) and 91.22% (1,341/1,470 cycles) for the within-day and between-day classification, respectively. When considering the within-day classification, a combination of two muscles was sufficient to obtain a classification rate >80% for both pedaling and gait. When considering between-day classification, a combination of four to five muscles was sufficient to obtain a classification rate >80% for pedaling and gait. These results demonstrate that strategies not only vary between individuals, as is often assumed, but are unique to each individual.

Rival theories of consciousness being tested by large project.

In the first phase of a $20 million dollar project, six laboratories are going to run experiments with more than 500 participants to test two of the primary theories of consciousness:

The first two contenders are the global workspace theory (GWT), championed by Stanislas Dehaene of the Collège de France in Paris, and the integrated information theory (IIT), proposed by Giulio Tononi of the Uni-versity of Wisconsin in Madison. The GWT says the brain’s prefrontal cortex, which con-trols higher order cognitive processes like decision-making, acts as a central computer that collects and prioritizes information from sensory input. It then broadcasts the infor-mation to other parts of the brain that carry out tasks. Dehaene thinks this selection pro-cess is what we perceive as consciousness. By contrast, the IIT proposes that conscious-ness arises from the interconnectedness of brain networks. The more neurons interact with one another, the more a being feels conscious—even without sensory input. IIT proponents suspect this process occurs in the back of the brain, where neurons con-nect in a gridlike structure...Tononi and Dehaene have agreed to pa-rameters for the experiments and have reg-istered their predictions. To avoid conflicts of interest, the scientists will neither collect nor interpret the data. If the results appear to disprove one theory, each has agreed to admit he was wrong—at least to some extent

The labs, in the United States, Germany, the United Kingdom, and China, will use three techniques to record brain activity as volun-teers perform consciousness-related tasks: functional magnetic resonance imaging, electroencephalography, and electrocortico-graphy (a form of EEG done during brain sur-gery, in which electrodes are placed directly on the brain). In one experiment, research-ers will measure the brain’s response when a person becomes aware of an image. The GWT predicts the front of the brain will suddenly become active, whereas the IIT says the back of the brain will be consistently active.

The real cost of texting and tweeting.

Agnes Callard, an associate professor of philosophy at the University of Chicago, crystallizes some fascinating points in an NYTimes Op-Ed piece. She wonders why she broadcasts the details of her daily life on twitter...some clips:

To allow others to think about us in whatever way they feel like — perhaps to laugh at us, perhaps to dismiss us — is a huge loss of control. So why do we allow it? What is the attraction of it? I think that it’s the increase in control we get in return. Social media has enabled the Great Control Swap. And it is happening right now, beneath our notice.

The first baby step toward the Great Swap was the shift from phone calls to texts. A phone interaction requires participants to be “on the same time,” which entails negotiations over entrance into and exit from the conversation...A text or email interaction, by contrast, liberates the parties so that each may operate on their own time. But the cost comes in another form of control: data....text-based communication requires stationary words...they leave a trail.

We understood from the start that this form of socializing — like an affair without physical contact — was shallower than the other, more demanding kind. We were prepared to accept that trade-off, but failed to grasp that we were trading away more than depth. We were also trading away a kind of control.

All of us have a desire to connect, to be seen. But we live in a world that is starting to allow us to satisfy that desire without feeling the common-sense moral strictures that have traditionally governed human relationships. We can engage without obligation, without boredom and, most importantly, without subjecting our attention to the command of another. On Twitter, I’m never obligated to listen through to the end of someone’s story.

The immense appeal of this free-form socializing lies in the way it makes one a master of one’s own time — but it cannot happen without a place. All that data has to sit somewhere so that people can freely access it whenever they wish. Data storage is the loss of control by which we secure social control: Facebook is our faithless mistress’s leaky inbox.

When we alienate our identities as text data, and put that data “out there” to be read by anyone who wanders by, we are putting ourselves into the interpretive hands of those who have no bonds or obligations or agreements with us, people with whom we are, quite literally, prevented from seeing “eye to eye.” People we cannot trust.

The Great Control Swap buys us control over the logistics of our interactions at the cost of interpretive control over the content of those interactions. Our words have lost their wings, and fallen to the ground as data.

Cognitive and noncognitive predictors of success.

An interesting bit of work from Duckworth et al.

When predicting success, how important are personal attributes other than cognitive ability? To address this question, we capitalized on a full decade of prospective, longitudinal data from n = 11,258 cadets entering training at the US Military Academy at West Point. Prior to training, cognitive ability was negatively correlated with both physical ability and grit. Cognitive ability emerged as the strongest predictor of academic and military grades, but noncognitive attributes were more prognostic of other achievement outcomes, including successful completion of initiation training and 4-y graduation. We conclude that noncognitive aspects of human capital deserve greater attention from both scientists and practitioners interested in predicting real-world success.

How trance states might have forged human societies

I want to pass on a series of clips I have made for my own use from an intriguing article by Mark Vernon in Aeon:

With anatomically modern humans comes culture in a way that had never happened before. And from that culture came religion, with various proposals to map the hows and whys of its emergence. Until recently, the proposals fell into two broad groups – ‘big gods’ theories and ‘false agency’ hypotheses. Big gods theories envisage religion as conjuring up punishing deities. These disciplining gods provided social bonding by telling individuals that wrongdoing incurs massive costs. The problem is that big gods are not a universal feature of religions and, if they are present, they seem correlated to big societies not causes of them. False agency hypotheses...assume that our forebears were jumpy and superstitious: they thought that a shrub swayed because of a spirit not the wind; and they were easily fooled, though their mistakes were evolutionarily advantageous because, on occasion, the swaying was caused by a predator. The false agency hypothesis has been tested and disconfirmed across many experiments.

...there is a need for a new idea, and coming to the fore now is an old one revisited...The explanation is resurfacing in what can be called the trance theory of religious origins, which proposes that our paleolithic ancestors hit on effervescence upon finding that they could induce altered states of consciousness...Effervescence is generated when humans come together to make music or perform rituals, an experience that lingers when the ceremonies are over. The suggestion, therefore, is that collective experiences that are religious or religious-like unify groups and create the energy to sustain them.

Research to test and develop this idea is underway in a multidisciplinary team led by Robin Dunbar at the University of Oxford. The approach appeals to him, in part, because it seems to capture a crucial aspect of religious phenomena missing in suggestions about punishing gods or dangerous spirits. It is not about the fine details of theology, but is about the raw feelings of experience...this raw-feelings element has a transcendental mystical component – something that is only fully experienced in trance states...this sense of transcendence and other worlds is present at some level in almost all forms of religious experience.

...there’s evidence that monkeys and apes experience the antecedents to ecstasy because they seem to experience wonder...a few hundred thousand years ago, archaic humans took a step that ramped up this capacity. They started deliberately to make music, dance and sing. When the synchronised and collective nature of these practices became sufficiently intense, individuals likely entered trance states in which they experienced not only this-worldly splendour but otherworldly intrigue... What you might call religiosity was born. It stuck partly because it also helped to ease tensions and bond groups, via the endorphin surges produced in trance states. In other words, altered states proved evolutionarily advantageous: the awoken human desire for ecstasy simultaneously prompted a social revolution because it meant that social groups could grow to much larger sizes via the shared intensity of heightened experiences.

The trance hypothesis...rests on the rituals that produce peak experiences, which means it doesn’t require speculating about what ancient people did or didn’t believe about spirits and gods...Asking when religion evolved is not a good question because religion is more than one thing...asking when the various elements such as supernatural agents and moral obligations started to coalesce together is a better question. And they invariably start to coalesce around rituals.

...when villages and then towns appear...new techniques for managing social pressures are required...religious systems (Doctrinal religions) that include specialists such as priests and impressive constructions we’d call temples and/or domestic house-based shrines...sustain the prosocial effects of earlier types of religiosity for groups that are now growing very large indeed...a tension .. arises when religious experiences are institutionalised....what’s on offer is somewhat thinner than experiences gained in the immersive rites that precipitate altered states. Encountering spirit entities directly in a dance or chase is not the same as the uplift offered by a monumental building.

...religions are caught between the Scylla of socially useful but potentially dreary religious rites and the Charybdis of altered states that are intrinsically exciting but socially disruptive. It’s why they bring bloody conflicts as well as social goods. This way of putting it highlights another feature of the trance theory. It interweaves two levels of explanation: one focused on the allure of spiritual vitality; the other on practical needs.

..science cannot decide whether the claims of any one religion are true. But the new theory still makes quite a strong claim, which brings me back to the role of the supernatural, transcendence and religious gods that today’s secularists seem inclined to sideline. If the science cannot confirm convictions about any divine revelations received, it does lend credence to the reasonableness, even necessity, of having them. Where the big gods and false agency hypotheses seemed inherently sniffy about human religiosity, the trance hypothesis positively values it...The trance hypothesis is neutral about the truth claims of religions whether you believe or don’t, though it does suggest that transcendent states of mind are meaningful to human beings and can evolve into religious systems of belief.

And in this final observation there is, perhaps, some good news for us, whether we’re religious or not. It’s often said that many of today’s troubles, from divisive political debates to spats on social media, are due to our tribal nature. It’s added, somewhat fatalistically, that deep within our evolutionary past is the tendency to identify with one group and demonise another. We are destined to be at war, culturally or otherwise. But if the trance theory is true, it shows that the evolutionary tendency to be tribal rests on an evolutionary taste for that which surpasses tribal experience – the transcendence that humans glimpsed in altered states of mind that enabled them to form tribes to start with.

If we long to belong, we also long to be in touch with ‘the more’, as the great pioneer of the study of religious experiences William James called it. That more will be envisaged in numerous ways. But it might help us by prompting new visions that exceed our herd instincts and binary thinking, and ease social tensions. If it helped our ancestors to survive, why would we think we are any different?

Evidence for premature aging caused by insufficient sleep.

I have come to realize in the past year or so that my physical and mental robustness require getting at least seven, and preferably eight, hours of sleep every night. Thus I was intrigued by finding an extensive and well documented study by Teo et al. (open source) showing that telomeres, sequences of DNA on the end of chromosomes taken as a marker of biological aging, are, on average, 356 base pairs shorter in study participants who slept for fewer than five hours per night than in those who slept for seven hours. They found that sleep metrics were reported more accurately by wearable fitness trackers than by self report. Here is the abstract of their article, titled "Digital phenotyping by consumer wearables identifies sleep-associated markers of cardiovascular disease risk and biological aging."

Sleep is associated with various health outcomes. Despite their growing adoption, the potential for consumer wearables to contribute sleep metrics to sleep-related biomedical research remains largely uncharacterized. Here we analyzed sleep tracking data, along with questionnaire responses and multi-modal phenotypic data generated from 482 normal volunteers. First, we compared wearable-derived and self-reported sleep metrics, particularly total sleep time (TST) and sleep efficiency (SE). We then identified demographic, socioeconomic and lifestyle factors associated with wearable-derived TST; they included age, gender, occupation and alcohol consumption. Multi-modal phenotypic data analysis showed that wearable-derived TST and SE were associated with cardiovascular disease risk markers such as body mass index and waist circumference, whereas self-reported measures were not. Using wearable-derived TST, we showed that insufficient sleep was associated with premature telomere attrition. Our study highlights the potential for sleep metrics from consumer wearables to provide novel insights into data generated from population cohort studies.

A "Department of the Attention Economy"

Popping up on my daily input stream (in this case the Google News aggregator - which knows more that I do about what I might like to see) is a CNN business perspective titled "Andrew Yang: As president, I will establish a Department of the Attention Economy." It is an idea that I wish some of the more likely democratic nominees would take up.

The article immediately caught my attention, because faced with the immense array of input text and video streams competing for my attention I feel, as I suspect many MindBlog readers do, like one of the dogs in Martin Seligman's classic learned helplessness experiments whose stress and immune systems eventually are compromised by uncertainty. For entertainment should I be subscribing to Netflix, Hulu, Amazon Prime, Disney+, YouTube +, Apple TV+, CBS All Access, AcornTV, Britbox, Shudder, YouTbue, Facebook Watch, Tubi, etc.? For news, there are too many options to even begin to list them. Apart from my own qualms about using Google as a prosthesis (Blogger, Google Docs, Calendar, Mail, etc.), I look at how my 5 and 7 year old grandsons' lives are potentially compromised by the amount of free time they spend on digital inputs rather than playing outside with friends.

Clips rom Yang's article:

...technology is addictive and damaging the mental health of our children. Research shows that too much time spent on social media increases stress, anxiety, depression and feelings of isolation. Other studies have found that extended screen time can negatively affect sleep...As president, I will establish a Department of the Attention Economy that will work with tech companies and implement regulations that curb the negative effects of smartphones and social media.

A few of his suggestions:

We can start by curbing design features that maximize screen time, such as removing autoplay video and capping recommendations for videos, articles and posts for each user each day. Platforms can also use deep-learning algorithms to determine whether a user is a child, and then explore capping the user's screen hours per day.

Design features that encourage social validation should also be removed. Instagram is leading the way by testing hiding likes on the posts of some users. That's a step in the right direction and it should be implemented as soon as possible. In addition, the number of followers a person has on social media should be hidden too, as it represents a false equivalence with a person's social standing.

Another area that deserves attention is the content our kids consume. When I was growing up, television time meant morning cartoons and after-school specials. Rules and standards should be established to protect kids from graphic content and violent imagery. Subsequently, these regulations would also incentivize the production of high-quality content and positive programming.

It shouldn't stop there. Parents have a major role to play — and they want to — but they could use some help. Companies should be required to provide parents with guidance on kid-healthy content (similar to the rating system for TV or movies), and parents should easily be able to monitor content and screen time for children.

Social class is revealed by brief clips of speech.

Kraus et al. - a collective modern version of Professor Henry Higgins in George Bernard Shaw's play Pygmalion - offer a detailed analytic update on how social class is reproduced through subtle cues expressed in brief speech. Here is their abstract:

Economic inequality is at its highest point on record and is linked to poorer health and well-being across countries. The forces that perpetuate inequality continue to be studied, and here we examine how a person’s position within the economic hierarchy, their social class, is accurately perceived and reproduced by mundane patterns embedded in brief speech. Studies 1 through 4 examined the extent that people accurately perceive social class based on brief speech patterns. We find that brief speech spoken out of context is sufficient to allow respondents to discern the social class of speakers at levels above chance accuracy, that adherence to both digital and subjective standards for English is associated with higher perceived and actual social class of speakers, and that pronunciation cues in speech communicate social class over and above speech content. In study 5, we find that people with prior hiring experience use speech patterns in preinterview conversations to judge the fit, competence, starting salary, and signing bonus of prospective job candidates in ways that bias the process in favor of applicants of higher social class. Overall, this research provides evidence for the stratification of common speech and its role in both shaping perceiver judgments and perpetuating inequality during the briefest interactions.

Here is a sample explanatory clip from their results section:

A total of 229 perceivers were asked to listen to the speech of 27 unique speakers whose utterances were collected as part of a larger sample of 189 speakers through the International Dialects of English Archive (IDEA). These 27 speakers varied in terms of age, race, gender, and social class, which we measured in the present study in terms of high school or college degree attainment. Our sample of perceivers listened to 7 words spoken by each of the speakers presented consecutively and randomly without any other accompanying speech and answered “Yes” or “No” to 4 questions: “Is this person a college graduate/woman/young/white?” Participants answered these 4 questions in a randomized order, and we calculated the proportion of correct responses for each question...

Explaining the puzzle of human diversity in the Christian world

Fascinating work by Schulz et al. is reviewed by both Gelfand and also Zauzmer. Schultz et al. show how the specific practices of Medieval Christianity can in part explain widespread variation in human psychology around the world.

From Zauzmer:

The story begins with kinship networks — the tribes and clans of densely connected, insular groups of relatives who formed most human societies before medieval times. Catholic Church teachings disrupted those networks, in large part by vehemently prohibiting marriage between relatives (which had been de rigeur), and eventually provoked a wholesale transformation of communities, changing the norm from large clans into small, monogamous nuclear families.

The team analyzed Vatican records to document the extent of a country or region’s exposure to Catholicism before the year 1500, and found that longer exposure to Catholicism correlated with low measures of kinship intensity in the modern era, including low rates of cousins marrying each other. Both measures correlated with psychology, the researchers found by looking at 24 different psychological traits of people in different cultures: Countries exposed to Catholicism early have citizens today who exhibit qualities such as being more individualistic and independent, and being more trusting of strangers.

From Gelfand:

...the authors found that both longer exposure to the Western Church and weaker kinship intensity (which were negatively related, as expected) were associated with greater individualism and independence, less conformity and obedience, and greater prosociality toward strangers—relationships that mostly held when controlling for a range of geographic variables. The results were replicated across 440 regions in 36 European countries: Longer exposure to the Western Church was generally associated with the same WEIRD (Western, Educated, Industrialized, Rich and Democratic) psychological shifts, even when controlling for alternate explanations (e.g., the influence of Roman political institutions, schooling, migration).

New work on how and why we sleep.

The fact that I'm finding the quality of my sleep to be central to my robustness and well-being makes me want to pass on descriptions of four pieces of work described in recent issues of Science Magazine, work showing housekeeping changes in our brains happening while we sleep, changes whose disruption by sleep deprivation has debilitating consequences. Fultz et al. show that deep sleep drives brain fluid oscillations that may facilitate communication between fluid compartments and clearance of waste products. Todorova and Zugaro show that spikes during delta waves of sleep (widespread cortical silence) support memory consolidation. Brüning et al. find in the mouse brain that half of the 2000 synaptic phosphoproteins quantified show changes with daily activity-rest cycles. Sleep deprivation abolishes nearly all (98%) of these phosphorylation cycles at synapses. Noya et al. find a sleep-wake cycle in which transcripts and proteins associated with synaptic signaling accumulate before the active phase (dusk for nocturnal mice), whereas messenger RNAs and proteins associated with metabolism and translation accumulate before the resting phase.

Why we can't tell the truth about aging.

I've enjoyed reading the New Yorker essay by Arthur Krystal titled "Why we can't tell the truth about aging," which points to and discusses numerous recent (as well as a few ancient) books on aging. Here is a selection of rearranged small clips from the article.

Average life expectancy was indeed a sorry number for the greater part of history (for Americans born as late as 1900, it wasn’t even fifty), which may be one reason that people didn’t write books about aging: there weren’t enough old folks around to sample them. But now that more people on the planet are over sixty-five than under five, an army of readers stands waiting to learn what old age has in store.

Now that we’re living longer, we have the time to write books about living longe...The library on old age has grown so voluminous that the fifty million Americans over the age of sixty-five could spend the rest of their lives reading such books, even as lusty retirees and power-lifting septuagenarians turn out new ones.

Our senior years are evidently a time to celebrate ourselves and the wonderful things to come: travelling, volunteering, canoodling, acquiring new skills, and so on. No one, it seems, wants to disparage old age...we get cheerful tidings...chatty accounts meant to reassure us that getting old just means that we have to work harder at staying young...authors aren’t blind to the perils of aging; they just prefer to see the upside. All maintain that seniors are more comfortable in their own skins.

There is, of course, a chance that you may be happier at eighty than you were at twenty or forty, but you’re going to feel much worse. I know this because two recent books provide a sobering look at what happens to the human body as the years pile up. Elizabeth Blackburn and Elissa Epel’s “The Telomere Effect: Living Younger, Healthier, Longer” and Sue Armstrong’s “Borrowed Time: The Science of How and Why We Age” describe what is essentially a messy business.

Basically, most cells divide and replicate some fifty-plus times before becoming senescent. Not nearly as inactive as the name suggests, senescent cells contribute to chronic inflammation and interfere with protective collagens...The so-called epigenetic clock shows our DNA getting gummed up, age-related mitochondrial mutations reducing the cells’ ability to generate energy, and our immune system slowly growing less efficient. Bones weaken, eyes strain, hearts flag. Bladders empty too often, bowels not often enough, and toxic proteins build up in the brain to form the plaque and the spaghetti-like tangles that are associated with Alzheimer’s disease. Not surprisingly, sixty-eight per cent of Medicare beneficiaries today have multiple chronic conditions. Not a lot of grace, force, or fascination in that.

In short, the optimistic narrative of pro-aging writers doesn’t line up with the dark story told by the human body. But maybe that’s not the point. “There is only one solution if old age is not to be an absurd parody of our former life,” Simone de Beauvoir wrote in her expansive 1970 study “The Coming of Age,” “and that is to go on pursuing ends that give our existence a meaning—devotion to individuals, to groups, or to causes—social, political, intellectual, or creative work.”

One would, of course, like to approach old age with grace and fortitude, but old age makes it difficult. Those who feel that it’s a welcome respite from the passions, anxieties, and troubles of youth or middle age are either very lucky or toweringly reasonable. Why rail against the inevitable—what good will it do? None at all. Complaining is both pointless and unseemly. Existence itself may be pointless and unseemly.

We should all make peace with aging. And so my hat is off to Dr. Oliver Sacks, who chose to regard old age as “a time of leisure and freedom, freed from the factitious urgencies of earlier days, free to explore whatever I wish, and to bind the thoughts and feelings of a lifetime together.”

World wide movement of people into cities is degrading the human microbiome

From the Oct. 25 issue of Science Magazine:

Sonnenburg and Sonnenburg review how the shift of recent generations from rural, outdoor environments to urbanized and industrialized settings has profoundly affected our biology and health. The signals of change are seen most strikingly in the reduction of commensal microbial taxa and loss of their metabolic functions. The extirpation of human commensals is a result of bombardment by new chemicals, foodstuffs, sanitation, and medical practices. For most people, sanitation and readily available food have been beneficial, but have we now reached a tipping point? How do we “conserve” our beneficial symbionts and keep the pathogens at bay?

Here is their abstract:

The human body is an ecosystem that is home to a complex array of microbes known as the microbiome or microbiota. This ecosystem plays an important role in human health, but as a result of recent lifestyle changes occurring around the planet, whole populations are seeing a major shift in their gut microbiota. Measures meant to kill or limit exposure to pathogenic microbes, such as antibiotics and sanitation, combined with other factors such as processed food, have had unintended consequences for the human microbial ecosystem, including changes that may be difficult to reverse. Microbiota alteration and the accompanying loss of certain functional attributes might result in the microbial communities of people living in industrialized societies being suboptimal for human health. As macroecologists, conservationists, and climate scientists race to document, understand, predict, and delay global changes in our wider environment, microbiota scientists may benefit by using analogous approaches to study and protect our intimate microbial ecosystems.

How human breeding has changed dogs’ brains

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

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

A triple drug combination increases lifespan by 48%

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

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

Skill development - the intelligence vs. practice debate reframed

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

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

The miracle cure - just move

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

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

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

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

Feeling grateful - a shortcut to virtuous behavior.

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

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

They then did a second experiment that..

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

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

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

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

Five myths about aging.

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

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

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

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

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

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

The Metamorphosis of the Western Soul

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

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

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

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

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

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

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

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

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

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

Abstract

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

The default mode network represents esthetic appeal.

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

Significance

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

Abstract

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

Cross-national negativity bias in reacting to news

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

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