Can You Have More Than 150 Friends?

MindBlog has done more than 9 posts over the past 15 years (enter Dunbar in the search box in the left column of this web page) pointing to Robin Dunbar's work showing that for a large number of animal species brain size and social group size get larger together, with his curve predicting that the optimal group size for humans is about 150. The staus of this widely accepted number has been challenged by Lind and collaborators, whose article suggests that the number could be much higher. Here is their abstract and a few clips from their discussion:

A widespread and popular belief posits that humans possess a cognitive capacity that is limited to keeping track of and maintaining stable relationships with approximately 150 people. This influential number, ‘Dunbar's number’, originates from an extrapolation of a regression line describing the relationship between relative neocortex size and group size in primates. Here, we test if there is statistical support for this idea. Our analyses on complementary datasets using different methods yield wildly different numbers. Bayesian and generalized least-squares phylogenetic methods generate approximations of average group sizes between 69–109 and 16–42, respectively. However, enormous 95% confidence intervals (4–520 and 2–336, respectively) imply that specifying any one number is futile. A cognitive limit on human group size cannot be derived in this manner.

Ruiter et al. make the point that

Dunbar's assumption that the evolution of human brain physiology corresponds with a limit in our capacity to maintain relationships ignores the cultural mechanisms, practices, and social structures that humans develop to counter potential deficiencies...Human information process management, we argue, cannot be understood as a simple product of brain physiology. Cross-cultural comparison of not only group size but also relationship-reckoning systems like kinship terminologies suggests that although neocortices are undoubtedly crucial to human behavior, they cannot be given such primacy in explaining complex group composition, formation, or management.

An article by Jenny Gross quotes Dunbar's responses to the above.

The new analysis, he said, “is bonkers, absolutely bonkers,” adding that the Stockholm University researchers conducted a flawed statistical analysis and misunderstood both the nuances of his analyses and of human connections. “I marvel at their apparent failure to understand relationships.”

Dr. Dunbar defines meaningful relationships as those people you know well enough to greet without feeling awkward if you ran into them in an airport lounge. That number typically ranges from 100 to 250, with the average around 150...Around 6000 B.C., the size of Neolithic villages from the Middle East was 120 to 150 people, judging by the number of dwellings. In 1086, the average size of most English villages recorded in the Domesday Book was 160 people. In modern armies, fighting units contain an average of 130 to 150 people, he said...Dr. Dunbar contended that his theory is still viable, even in today’s hyper-connected world, since the quality of connections on social networks is often low. “These are not personalized relationships,” he said...“It’s fairly blatantly obvious to most people when they sit down and think about it that that’s how their social network is organized,” he said. Dunbar’s number, he said, is not going anywhere.

For consciousness theory mavens: an argument against Tononi’s Integrated Information Theory.

Behavioral and Brain Science invites commentary on a forthcoming article by Merker et al. Here is the abstract:

Giulio Tononi's Integrated Information Theory (IIT) proposes explaining consciousness by directly identifying it with integrated information. We examine the construct validity of IIT's measure of consciousness, phi (Φ), by analyzing its formal properties, its relation to key aspects of consciousness, and its co-variation with relevant empirical circumstances. Our analysis shows that IIT's identification of consciousness with the causal efficacy with which differentiated networks accomplish global information transfer (which is what Φ in fact measures) is mistaken. This misidentification has the consequence of requiring the attribution of consciousness to a range of natural systems and artifacts that include, but are not limited to, large-scale electrical power grids, gene-regulation networks, some electronic circuit boards, and social networks. Instead of treating this consequence of the theory as a disconfirmation, IIT embraces it. By regarding these systems as bearers of consciousness ex hypothesi, IIT is led towards the orbit of panpsychist ideation. This departure from science as we know it can be avoided by recognizing the functional misattribution at the heart of IIT's identity claim. We show, for example, what function is actually performed, at least in the human case, by the cortical combination of differentiation with integration that IIT identifies with consciousness. Finally, we examine what lessons may be drawn from IIT's failure to provide a credible account of consciousness for progress in the very active field of research concerned with exploring the phenomenon from formal and neural points of view.

I owe my soul to the company store (Google).

As I pass through my 79th birthday I offer a cathartic rant - without worrying about whether its parts cohere:

I am the white collar equivalent of the coal miner in Tennessee Ernie Fords classic “16 Tons” lyric line that provides the title of this post.... except that I am shoveling information in bytes rather than shoveling coal. The tendrils of google extend into all my internet activities, it is a virtual prosthesis. I am symbiotic with the cloud, losing access to it is like losing the use of my limbs. Yuval Harari has it exactly right - Google’s A.I. knows more about me than I know about myself... what YouTube movies, programs, and classical piano performances with scrolling scores I want to watch, where I go (my google maps) and what I do (my google calendar). 

Google knows what I think and write from https://mindblog.dericbownds.net/ (powered by Google’s Blogger platform), as well from my google cloud drive that holds my important legal and financial documents.  I put my piano performances on my YouTube channel at https://www.youtube.com/DericPiano. My techie son’s Google workspace account supporting the bownds.com domain provides me with a deric@bownds.com email address and youtube without advertisements. Underground Google fiber was recently installed on my street and suddenly this week I have 1 GB down internet and google drive cloud storage of 1 terabyte for the same amount that I had been paying another fiber optic provider for 300 MB down with no extras.

My only non-Google platform, http://www.dericbownds.net/  (the archive of my lectures, writing, personal and laboratory history), is a historical relic dating back to geocities.com and now called  'Yahoo Small Business." I tried switching mainly to Apple’s iCloud in early 2020, because it is more protective of privacy, but after a year of trying I have given up and returned to the evil empire. Apple’s web interface for word processing is slow and klutzy, has unnecessary prompts, is crash prone, and too frequently requires relogging into iCloud. 

Governance of me, along with the rest of the human herd, is quietly being transferred from nation states - whose internal conflicts render them ineffective - to an oligarchy of IT companies like Google, Apple, Microsoft, Facebook, and Amazon, along with their European and Asian counterparts. Tech companies are pretending to be governments, as in the quasi-governmental posturing of Amazon and Facebook . Their cloud based artificial intelligence analyzes and manipulates what we want and sells it to us.

After doing numerous posts on the sociopathy of social media, you might think I would practice what I preach and abstain from having a facebook and twitter account. But no, I maintain both accounts (Deric Bownds and @DericBownds)  to re-broadcast the posts I compose on the Blogger platform that masquerades as coming from mindblog.dericbownds.net. I don’t look at tweets or re-tweets on my twitter account, but I do check facebook for news of my family and two facebook social groups. 

I am continually amazed by my occasional looks down the rabbit hole of social media (See How Roblox Sparked a Chaotic Music Scene)  Realizing that this is the generation that contains our future leaders reminds me of Willian Butler Yeats' poem “The Second Coming” in which he seems to have seen it long ago:

Things fall apart; the centre cannot hold; 

Mere anarchy is loosed upon the world, The blood-dimmed tide is loosed, and everywhere

The ceremony of innocence is drowned;

The best lack all conviction, while the worst

Are full of passionate intensity.

Surely some revelation is at hand; 

Surely the Second Coming is at hand.

What's not to enjoy?  Sit back and read Niall Ferguson on "The Politics of Catastrophe" as our humanity slowly and surely chaotically merges with the great A.I. in the cloud!

Educational attainment does not influence brain aging

Well...so much for my smugness over knowing that educational attainment slows brain aging. Nyberg et al. (open souce) show that it ain't so. Check out the link for some nice graphic of their data:

Education has been related to various advantageous lifetime outcomes. Here, using longitudinal structural MRI data (4,422 observations), we tested the influential hypothesis that higher education translates into slower rates of brain aging. Cross-sectionally, education was modestly associated with regional cortical volume. However, despite marked mean atrophy in the cortex and hippocampus, education did not influence rates of change. The results were replicated across two independent samples. Our findings challenge the view that higher education slows brain aging.

The curiosity circuits of our brains.

Every morning, as I am passing through the waking, exercise, and breakfast rituals that finally deliver me to my 'professor is in' office - a converted front bedroom of our house - I marvel at parallel ritualistic behaviors in my two abyssinian 1 year old cats, driven by an almost manic curiosity that impells them to seek new objects, crannies and nooks that hey can explore, occasionally hitting the jackpot of finding a cockroach, or a new object that they can break or brush onto the floor. Curiosity is one of the most important innate drives that they or I posses, and many think it should elevated to join the list of the four F's we teach first year Medical Students (fighting, feeding, fleeing, and fornicating). As Farahbakhsh and Siciliano note in their perspectives article on the work of Ahmadlout et al., "Attraction to the unknown, or curiosity, is a prerequisite for higher-order knowledge. Innate attraction to novelty is thought to be an evolutionary prerequisite for complex learning and guides organisms toward acquisition of adaptive behavioral repertoires."

Ahmadlou et al. have found circuitry in the mouse brain that is necessary for the exploration of new objects and conspecifics. A specific population of genetically identified γ-aminobutyric acid (GABA)—ergic neurons in a brain region called the zona incerta receive excitatory input in the form of novelty and/or arousal information from the prelimbic cortex, and these neurons send inhibitory projections to the periaqueductal gray region. Here is a summary graphic from the perspectives article (click to enlarge):

 

Liberal fact-master nerds go down the rabbit hole of a social media conspiracy.

I pass on this clip from the Morning Dispatch sent by a friend. Check out the link to the NYTimes article it refers to. Ben Smith describes how hundreds of “Jeopardy!” contestants talked themselves into a baseless conspiracy theory — and won’t be talked out of it.

It’s tempting to believe that conspiratorial, tin-hat thinking is something only other people are susceptible to—especially people less educated and more credulous than we imagine ourselves to be. Which is why this piece from the New York Times’s Ben Smith is so fascinating in its depiction of a moral panic that descended on a small online community of former winners of the quiz show Jeopardy! after a contestant who had just won his third game held up three fingers on his right hand—a gesture which, the contestants quickly decided, was likely some sort of white power symbol. “The element of this story that interests me most is how the beating heart of nerdy, liberal fact-mastery can pump blood into wild social media conspiracy, and send all these smart people down the sort of rabbit hole that leads other groups of Americans to believe that children are being transported inside refrigerators,” Smith wrote. “It reflects a depth of alienation among Americans, in which our warring tribes squint through the fog at one another for mysterious and abstruse signs of malice.”

How both tribes are missing the mark

Continuing in the thread of last Monday's post, I can't resist passing on three articles that absolutely nail the current dilemma in the U.S. and Western Europe over finding a middle way between the extremes of reactionary progressivism and conservatism. Here is a clip from Andrew Sullivan, that includes reference to a must read article by Tony Blair. His point is that the current GOP is missing an opportunity to capitalize on the following opportunity:

Everywhere in the West, this is now the winning electoral formula: left on economics, right on culture. By “left on economics”, I mean a recognition that market capitalism has been too successful for its and our own good, and that spreading the wealth to more people is needed both for social stability and to rescue capitalism from itself. And by “right on culture”, I do not mean some kind of revived Christianism. I mean affirming a critical but undeniable love of country and its flawed but inspiring history, reforming rather than defunding the police, enforcing the nation’s borders with firmness and compassion, embracing color-blind policies on race, and viewing our common humanity and citizenship as deeper principles than the modern left’s and radical right’s obsession with group identity.

Get that balance right, and the future is yours. In a must-read essay in Britain’s New Statesman, Tony Blair spells out how the progressive left is still misreading the public mood, allowing a cannier, less rigid right to entrench power. Money quote: “‘Defund the police’ may be the left’s most damaging political slogan since ‘the dictatorship of the proletariat’ … It leaves the right with an economic message which seems more practical, and a powerful cultural message around defending flag, family and fireside traditional values.” Some key principles Blair lays out:

People do not like their country, their flag or their history being disrespected. The left always gets confused by this sentiment and assume this means people support everything their country has done or think all their history is sacrosanct. They don’t. But they query imposing the thinking of today on the practices of yesterday … People like common sense, proportion and reason. They dislike prejudice; but they dislike extremism in combating prejudice.

The third article I point to is an add-on to the above. Brooks' piece suggests that the wokeness, social justice, or critical race theory of the left is likely to be co-opted by the meritocratic elite of corporations and other establishment organizations. "In the 1960s, left-wing radicals wanted to overthrow capitalism. We ended up with Whole Foods. The co-optation of wokeness seems to be happening right now."

Two promising post-traumatic stress disorder treatments

I want to pass on references to two new approaches to relieving the symptoms of post-traumatic stress disorder (PTSD). Nuwer describes a new study showing that MDMA (known as the party drug Ecstasy, or Molly) can bring relief to PTSD when used in conjunction with talk therapy. Ressler et al. address the problem that human patients cannot be directly re-exposed to trauma-cues of the sort that have been used in animal studies to induce and then disrupt reconsolidation of traumatic memories. They devise a procedure for covertly capturing and attenuating a hippocampu-dependent fear memory in male rats, a procedure that might prove to be useful in human therapy. Here is their abstract:

Reconsolidation may be a viable therapeutic target to inhibit pathological fear memories. In the clinic, incidental or imaginal reminders are used for safe retrieval of traumatic memories of experiences that occurred elsewhere. However, it is unknown whether indirectly retrieved traumatic memories are sensitive to disruption. Here we used a backward (BW) conditioning procedure to indirectly retrieve and manipulate a hippocampus (HPC)-dependent contextual fear engram in male rats. We show that conditioned freezing to a BW conditioned stimulus (CS) is mediated by fear to the conditioning context, activates HPC ensembles that can be covertly captured and chemogenetically activated to drive fear, and is impaired by post-retrieval protein synthesis inhibition. These results reveal that indirectly retrieved contextual fear memories reactivate HPC ensembles and undergo protein synthesis-dependent reconsolidation. Clinical interventions that rely on indirect retrieval of traumatic memories, such as imaginal exposure, may open a window for editing or erasure of neural representations that drive pathological fear.

Social isolation makes us stupid.

The summary of an open source article from Ingram et al. in the Journal of Applied Cognitive Psychology:

Studies examining the effect of social isolation on cognitive function typically involve older adults and/or specialist groups (e.g., expeditions). We considered the effects of COVID‐19‐induced social isolation on cognitive function within a representative sample of the general population. We additionally considered how participants ‘shielding’ due to underlying health complications, or living alone, performed. We predicted that performance would be poorest under strictest, most‐isolating conditions. At five timepoints over 13 weeks, participants (N = 342; aged 18–72 years) completed online tasks measuring attention, memory, decision‐making, time‐estimation, and learning. Participants indicated their mood as ‘lockdown’ was eased. Performance typically improved as opportunities for social contact increased. Interactions between participant sub‐groups and timepoint demonstrated that performance was shaped by individuals' social isolation levels. Social isolation is linked to cognitive decline in the absence of ageing covariates. The impact of social isolation on cognitive function should be considered when implementing prolonged pandemic‐related restrictive conditions.

Tribe trumps truth.

I've been trying to cut down on the number of posts on politics, but with the republican party now requiring a loyalty test that is the modern equivalent the firewalking rituals of Polynesia, Spain, and Greece I want to pass on a few articles relevant to their transition into a white anglo-saxon tribe that seeks to establish an autocratic regime that will preserve their minority ruling status. First, Brooks notes that

...Since the election, large swaths of the Trumpian right have decided America is facing a crisis like never before and they are the small army of warriors fighting with Alamo-level desperation to ensure the survival of the country as they conceive it...When asked in late January if politics is more about “enacting good public policy” or “ensuring the survival of the country as we know it,” 51 percent of Trump Republicans said survival; only 19 percent said policy...The level of Republican pessimism is off the charts. A February Economist-YouGov poll asked Americans which statement is closest to their view: “It’s a big, beautiful world, mostly full of good people, and we must find a way to embrace each other and not allow ourselves to become isolated” or “Our lives are threatened by terrorists, criminals and illegal immigrants, and our priority should be to protect ourselves.”...Over 75 percent of Biden voters chose “a big, beautiful world.” Two-thirds of Trump voters chose “our lives are threatened.”

Douthat describes the two crises of conservatism:

The normal crisis is a party crisis, the sort that afflicts all political coalitions. The Republican Party 40 years ago coalesced around a set of appeals that enabled its leaders to win large presidential majorities and set the national agenda. At a certain point the issue landscape changed, so did the country’s demographics, and the G.O.P. has struggled to adapt — cycling through compassionate conservatism, Tea Party conservatism and Trumpist populism without reproducing Ronald Reagan’s success.

But beneath this party crisis there is the deeper one, having to do with what conservatism under a liberal order exists to actually conserve...One powerful answer is that conservatism-under-liberalism should defend human goods that are threatened by liberal ideas taken to extremes. The family, when liberal freedom becomes a corrosive hyper-individualism. Traditional religion, when liberal toleration becomes a militant and superstitious secularism. Local community and local knowledge, against expert certainty and bureaucratic centralization. Artistic and intellectual greatness, when democratic taste turns philistine or liberal intellectuals become apparatchiks. The individual talent of the entrepreneur or businessman, against the leveling impulses of egalitarianism and the stultifying power of monopoly...

but,

What does it mean to conserve the family in an era when not just the two-parent household but childbearing and sex itself are in eclipse? What does it mean to defend traditional religion in a country where institutional faith is either bunkered or rapidly declining? How do you defend localism when the internet seems to nationalize every political and cultural debate? What does the conservation of the West’s humanistic traditions mean when pop repetition rules the culture, and the great universities are increasingly hostile to even the Democratic-voting sort of cultural conservative?

A further Douthat piece suggests that it is capitalism itself that is killing conservatism:

...the social trends American conservatives most dislike, the rise of expressive individualism and the decline of religion, marriage and the family, are driven by socioeconomic forces the right’s free-market doctrines actively encourage. “America’s moral traditionalists are wedded to an economic system that is radically anti-traditional,” he writes, and “Republicans can neither wage war on capitalism nor make peace with its social implications.”

...it’s not that capitalist dynamism inevitably dissolves conservative habits. It’s more that the wealth this dynamism piles up, the liberty it enables and the technological distractions it invents, let people live more individualistically — at first happily, with time perhaps less so — in ways that eventually undermine conservatism and dynamism together. At which point the peril isn’t markets red in tooth and claw, but a capitalist endgame that resembles Aldous Huxley’s “Brave New World,” with a rich and technologically proficient world turning sterile and dystopian.

...let’s not let liberals off the hook. If capitalist churn isn’t what it used to be, if taming its excesses in the style of France or Sweden isn’t enough to restore family and community, if the combination of welfare-state liberalism and personal emancipation trends toward a Huxleyan dystopia, do liberals have any resources besides complaints about capitalism that might help pull us off that course?...Because if conservatism’s responses are incoherent and insufficient, I fear that liberalism has no response at all.

Structural Whitening

I pass on this summary by Rai of a study by Anicich et al. in J. Exp. Soc. Psychol:

As the US population becomes more racially diverse, it is unclear how ethnic white populations will respond to these demographic changes. Anicich et al. found experimentally that when white Americans were given the opportunity to populate fictional cities, they imposed greater racial segregation in areas that they frequented more often, such as work or school, because they feel greater anxiety around non-whites. In a follow-up study, the authors examined policies at tennis and golf clubs across the United States, and found that in areas with higher racial diversity, clubs engaged in more exclusionary behavior, such as enacting strict dress codes. These findings suggest that as racial diversity increases, white Americans may respond by trying to structure their environment in more segregated ways.

And here is the abstract of the article:

The current research explores how local racial diversity affects Whites' efforts to structure their local communities to avoid incidental intergroup contact. In two experimental studies (N = 509; Studies 1a-b), we consider Whites' choices to structure a fictional, diverse city and find that Whites choose greater racial segregation around more (vs. less) self-relevant landmarks (e.g., their workplace and children's school). Specifically, the more time they expect to spend at a landmark, the more they concentrate other Whites around that landmark, thereby reducing opportunities for incidental intergroup contact. Whites also structure environments to reduce incidental intergroup contact by instituting organizational policies that disproportionately exclude non-Whites: Two large-scale archival studies (Studies 2a-b) using data from every U.S. tennis (N = 15,023) and golf (N = 10,949) facility revealed that facilities in more racially diverse communities maintain more exclusionary barriers (e.g., guest policies, monetary fees, dress codes) that shield the patrons of these historically White institutions from incidental intergroup contact. In a final experiment (N = 307; Study 3), we find that Whites' anticipated intergroup anxiety is one driver of their choices to structure environments to reduce incidental intergroup contact in more (vs. less) racially diverse communities. Our results suggest that despite increasing racial diversity, White Americans structure local environments to fuel a self-perpetuating cycle of segregation.

Evidence that monkeys have conscious awareness of self - they know what they saw.

Ben-Haim et al. Disentangle perceptual awareness from nonconscious processing in rhesus monkeys  

Significance

Many animals perform complex intelligent behaviors, but the question of whether animals are aware while doing so remains a long debated but unanswered question. Here, we develop a new approach to assess whether nonhuman animals have awareness by utilizing a well-known double dissociation of visual awareness—cases in which people behave in completely opposite ways when stimuli are processed consciously versus nonconsciously. Using this method, we found that a nonhuman species—the rhesus monkey—exhibits the very same behavioral signature of both nonconscious and conscious processing. This opposite double dissociation of awareness firstly allows stripping away the long inherent ambiguity when interpreting the processes governing animal behavior. Collectively, it provides robust support for two distinct awareness modes in nonhuman animals.

Abstract

Scholars have long debated whether animals, which display impressive intelligent behaviors, are consciously aware or not. Yet, because many complex human behaviors and high-level functions can be performed without conscious awareness, it was long considered impossible to untangle whether animals are aware or just conditionally or nonconsciously behaving. Here, we developed an empirical approach to address this question. We harnessed a well-established cross-over double dissociation between nonconscious and conscious processing, in which people perform in completely opposite ways when they are aware of stimuli versus when they are not. To date, no one has explored if similar performance dissociations exist in a nonhuman species. In a series of seven experiments, we first established these signatures in humans using both known and newly developed nonverbal double-dissociation tasks and then identified similar signatures in rhesus monkeys (Macaca mulatta). These results provide robust evidence for two distinct modes of processing in nonhuman primates. This empirical approach makes it feasible to disentangle conscious visual awareness from nonconscious processing in nonhuman species; hence, it can be used to strip away ambiguity when exploring the processes governing intelligent behavior across the animal kingdom. Taken together, these results strongly support the existence of both nonconscious processing as well as functional human-like visual awareness in nonhuman animals.

(Note: Establishing double dissociation of awareness used a nonverbal spatial-cueing paradigm. Motivated readers can email me to obtain a PDF of the article which describes this paradigm.)

People have shaped most of terrestrial nature for at least 12,000 years

From Ellis et al.L 

Significance

The current biodiversity crisis is often depicted as a struggle to preserve untouched habitats. Here, we combine global maps of human populations and land use over the past 12,000 y with current biodiversity data to show that nearly three quarters of terrestrial nature has long been shaped by diverse histories of human habitation and use by Indigenous and traditional peoples. With rare exceptions, current biodiversity losses are caused not by human conversion or degradation of untouched ecosystems, but rather by the appropriation, colonization, and intensification of use in lands inhabited and used by prior societies. Global land use history confirms that empowering the environmental stewardship of Indigenous peoples and local communities will be critical to conserving biodiversity across the planet.

Abstract

Archaeological and paleoecological evidence shows that by 10,000 BCE, all human societies employed varying degrees of ecologically transformative land use practices, including burning, hunting, species propagation, domestication, cultivation, and others that have left long-term legacies across the terrestrial biosphere. Yet, a lingering paradigm among natural scientists, conservationists, and policymakers is that human transformation of terrestrial nature is mostly recent and inherently destructive. Here, we use the most up-to-date, spatially explicit global reconstruction of historical human populations and land use to show that this paradigm is likely wrong. Even 12,000 y ago, nearly three quarters of Earth’s land was inhabited and therefore shaped by human societies, including more than 95% of temperate and 90% of tropical woodlands. Lands now characterized as “natural,” “intact,” and “wild” generally exhibit long histories of use, as do protected areas and Indigenous lands, and current global patterns of vertebrate species richness and key biodiversity areas are more strongly associated with past patterns of land use than with present ones in regional landscapes now characterized as natural. The current biodiversity crisis can seldom be explained by the loss of uninhabited wildlands, resulting instead from the appropriation, colonization, and intensifying use of the biodiverse cultural landscapes long shaped and sustained by prior societies. Recognizing this deep cultural connection with biodiversity will therefore be essential to resolve the crisis.

Motivated readers can obtain a PDF of the article by emailing me.

Excess mortality rates since 2000 in the US compared with Europe.

Interesting, from Preston and Vierboom. Just the numbers, no commentary on the causes (mainly opioid crisis?).

We use three indexes to identify how age-specific mortality rates in the United States compare to those in a composite of five large European countries since 2000. First, we examine the ratio of age-specific death rates in the United States to those in Europe. These show a sharp deterioration in the US position since 2000. Applying European age-specific death rates in 2017 to the US population, we then show that adverse mortality conditions in the United States resulted in 400,700 excess deaths that year. Finally, we show that these excess deaths entailed a loss of 13.0 My of life. In 2017, excess deaths and years of life lost in the United States represent a larger annual loss of life than that associated with the COVID-19 epidemic in 2020.

Age-specific comparisons of US and European mortality: 2000, 2010,2017. Source: HMD (12). (A) Ratio of US age-specific death rate to Europeanstandard. (B) Change in US death count if US had European age-specificdeath rates. (C) Years of life lost based on US life expectancies and US/European comparisons of age-specific death rates

Embracing diversity can disadvantage minorities

From Starck et al.:  

Significance

There are numerous reasons why institutions of higher education may choose to embrace diversity. A common rationale sanctioned by the US Supreme Court is that diversity provides compelling educational benefits and is thus instrumentally useful. We show that such instrumental rationales are the predominant rationale for diversity efforts in American higher education, are preferred by White Americans and not by Black Americans, that they are expected to advantage White Americans, and that they correspond to greater racial disparities in academic achievement. Overall, these findings suggest that the rationales behind universities’ embrace of diversity have nonlegal consequences that should be considered in institutional decision making.

Abstract

It is currently commonplace for institutions of higher education to proclaim to embrace diversity and inclusion. Though there are numerous rationales available for doing so, US Supreme Court decisions have consistently favored rationales which assert that diversity provides compelling educational benefits and is thus instrumentally useful. Our research is a quantitative/experimental effort to examine how such instrumental rationales comport with the preferences of White and Black Americans, specifically contrasting them with previously dominant moral rationales that embrace diversity as a matter of intrinsic values (e.g., justice). Furthermore, we investigate the prevalence of instrumental diversity rationales in the American higher education landscape and the degree to which they correspond with educational outcomes. Across six experiments, we showed that instrumental rationales correspond to the preferences of White (but not Black) Americans, and both parents and admissions staff expect Black students to fare worse at universities that endorse them. We coded university websites and surveyed admissions staff to determine that, nevertheless, instrumental diversity rationales are more prevalent than moral ones are and that they are indeed associated with increasing White–Black graduation disparities, particularly among universities with low levels of moral rationale use. These findings indicate that the most common rationale for supporting diversity in American higher education accords with the preferences of, and better relative outcomes for, White Americans over low-status racial minorities. The rationales behind universities’ embrace of diversity have nonlegal consequences that should be considered in institutional decision making.

Sensitivity to geometric shape: A putative signature of human singularity

From Sablé-Meyer et al.:

Among primates, humans are special in their ability to create and manipulate highly elaborate structures of language, mathematics, and music. Here we show that this sensitivity to abstract structure is already present in a much simpler domain: the visual perception of regular geometric shapes such as squares, rectangles, and parallelograms. We asked human subjects to detect an intruder shape among six quadrilaterals. Although the intruder was always defined by an identical amount of displacement of a single vertex, the results revealed a geometric regularity effect: detection was considerably easier when either the base shape or the intruder was a regular figure comprising right angles, parallelism, or symmetry rather than a more irregular shape. This effect was replicated in several tasks and in all human populations tested, including uneducated Himba adults and French kindergartners. Baboons, however, showed no such geometric regularity effect, even after extensive training. Baboon behavior was captured by convolutional neural networks (CNNs), but neither CNNs nor a variational autoencoder captured the human geometric regularity effect. However, a symbolic model, based on exact properties of Euclidean geometry, closely fitted human behavior. Our results indicate that the human propensity for symbolic abstraction permeates even elementary shape perception. They suggest a putative signature of human singularity and provide a challenge for nonsymbolic models of human shape perception.

What coffee does to body and mind

I am completely dependent on coffee, starting every morning with this stimulant and continuing small sips until a lunchtime cappuccino terminates my consumption for the day. Thus I found this article by Michael Gross on the history of caffeine consumption by humans and animals completely fascinating. I'll pass on just the first few paragraphs to whet your appetite, and let you download the complete article if you would like to continue reading on to Gross's discussion of coffee's effects on brain and mind. 

 

Johann Sebastian Bach never wrote an opera, simply because his employers had no use for one and kept him busy with other things. An intriguing glimpse at what the world missed is afforded by the secular cantata Schweigt stille, plaudert nicht (BWV 211), a half-hour mini-opera about a young woman addicted to coffee and her father trying to persuade her to quit. Bach is thought to have composed the work known as the ‘coffee cantata’ on the words of Picander in the 1730s, when he was the St Thomas Cantor at Leipzig and conducted an orchestra at the Café Zimmermann as a sideline.

It dates from a time when coffee was a new-fangled fashion craze gradually spreading across Europe. From myth-shrouded origins in the kingdom of Sheba, today’s Yemen or Ethiopia, the culture of making and drinking coffee expanded across the Arabian Peninsula and into the Ottoman Empire, reaching its capital, Istanbul, in 1554. After the Ottoman advance into Europe was stopped just outside Vienna in 1683, the victorious Austrians confiscated the coffee supplies of the fleeing Turks and used them to launch their legendary coffee-house culture, which spread across Europe. An independent early entry route was provided by Venetian traders.

From the beginnings of this spread there had been attempts by religious leaders, in both Islamic and Christian societies, to ban coffee, as they found its powerful stimulating effect suspicious. Thus, the lively conflict in Bach’s coffee cantata reflected a very real debate that must have taken place many times between lovers of the dark brew and authorities suspicious of its effects.

Ancient Greece's Army of Lovers

This post is under MindBlog's "random and curious stuff" category. A piece by Daniel Mendelsohn in The New Yorker:

Comprising a hundred and fifty male couples, Thebes’s Sacred Band was undefeated until it was wiped out in 338 B.C. In the nineteenth century, the mass grave of the men was found.

Image courtesy Hellenic Ministry of Culture and Sports, Directorate of the Management of the National Archive of Monuments, Department of the Historical Archive of Antiquities and Restorations

In June, 1818, during a visit to central Greece, a young English architect named George Ledwell Taylor went out riding with some friends in order to explore the ruins of an ancient town called Chaeronea. As Taylor’s party neared its destination, his horse took a “fearful stumble,” as he later recalled, on a stone in the roadway; on further inspection, he saw that the stone was, in fact, part of a sculpture. Energetic digging eventually revealed an animal head nearly six feet high—or, as Taylor put it, a “colossal head of the Lion.”

That definite article and the capital “L” are crucial. Taylor realized that he had uncovered a famous monument, mentioned in some historical sources but since lost, known as the Lion of Chaeronea. The Englishman had been studying a work called “The Description of Greece,” by Pausanias, a geographer of the second century A.D., which states that the gigantic figure of the sitting animal had been erected to commemorate a remarkable military unit that had perished there. The lion, Pausa­nias surmised, represented “the spirit of the men.”

The unit to which those men belonged was known as the Sacred Band. Comprising three hundred warriors from the city of Thebes, it was among the most fearsome fighting forces in Greece, undefeated until it was wiped out at the Battle of Chaeronea, in 338 B.C.—an engagement during which Philip of Macedon and his son, the ­future Alexander the Great, crushed a coalition of Greek city-states led by Athens and Thebes. Scholars see Chaeronea as the death knell of the Classi­cal Era of Greek history.

Others might find the story interesting for different reasons. Not the least of these is that the Band was composed entirely of lovers: precisely a hundred and fifty couples, whose valor, so the Greeks thought, was due to the fact that no man would ever exhibit cowardice or act dishonorably in front of his beloved. In Plato’s Symposium, a dialogue about love, a character remarks that an army made up of such lovers would “conquer all mankind.”

Sixty years after George Taylor’s horse stumbled, further excavations revealed a large rectangular burial site near the Lion. Drawings that were made at the site show seven rows of skeletons, two hundred and fifty-four in all. For “The Sacred Band” (Scribner), a forthcoming book by the classicist James Romm, the illustrator Markley Boyer collated those nineteenth-century drawings to produce a reconstruction of the entire mass grave. Black marks indicate wounds. A number of warriors were buried with arms linked; if you look closely, you can see that some were holding hands. ♦

Gamma-frequency oscillations link different brain regions during learning.

Fernández-Ruiz et al. demonstrate that specific, projected gamma-frequency oscillation patterns dynamically engage functionally related cell assemblies across brain regions in a task-specific manner. I pass along their entire structured abstract:  

INTRODUCTION

Learning induces a dynamic reorganization of brain circuits but the neuronal mechanisms underlying this process are not well understood. Interregional gamma-frequency oscillations (~30 to 150 Hz) have been postulated as a mechanism to precisely coordinate upstream and downstream neuronal ensembles, for example, in the hippocampal system. The lateral (LEC) and medial (MEC) entorhinal cortex receive inputs from two distinct streams of cortical hierarchy (the “what” and the “where” pathways) and convey these neuronal messages to the hippocampus. However, the mechanisms by which such messages are packaged and integrated or segregated by hippocampal circuits had yet to be explored.

RATIONALE

Neuronal assemblies firing within gamma time frames in an upstream region can most effectively discharge their downstream partners. This gamma-time-scale organization appears essential for physiological functions because manipulations that impair precision timing of spikes in the hippocampus often affect behavior. However, direct support for distinct gamma-frequency communication in appropriate behavioral situations is missing. To bring physiological operations closer to behavior, we designed “spatial” and “object” learning tasks and examined the selective engagement of gamma-frequency communication between the MEC and LEC inputs and their target neuronal assemblies in the hippocampal dentate gyrus. We combined these correlational observations with optogenetic perturbation of gamma oscillations in LEC and MEC, respectively, to test their roles in pathway-specific neuronal communication and learning.

RESULTS

During spatial learning, fast gamma (100 to 150 Hz) oscillations synchronized MEC and dentate gyrus and entrained predominantly granule cells. During object learning, slow gamma (30 to 50 Hz) oscillations synchronized LEC and dentate gyrus and preferentially recruited mossy cells and CA3 pyramidal neurons, suggesting task-specific routing of MEC and LEC messages in the form of gamma-cycle-spike packets of selected cell types. The low- and high-frequency gamma sub-bands were dominant in the outer and middle third of the dentate molecular layer, respectively, and their amplitude maxima were locked to different phases of theta oscillations.

Gamma frequency optogenenetic perturbation of MEC and LEC led to learning impairments in a spatial and object learning task, respectively. In the same animals, the dentate layer–specific low- and high-frequency gamma sub-bands and spike-gamma LFP coupling were selectively reduced, coupled with deterioration of spatial and object-related firing of dentate neurons.

CONCLUSION

These findings demonstrate that distinct gamma-frequency-specific communication between MEC and LEC and hippocampal cell assemblies are critical for routing task-relevant information, and our selective gamma-band perturbation experiments suggest that they support specific aspects of learning. We hypothesize that sending neuronal messages by segregated gamma-frequency carriers allows a target “reader” area to disambiguate convergent inputs. In general, these results demonstrate that specific projected gamma patterns dynamically engage functionally related cell assemblies across brain regions in a task-specific manner.

Vision: What’s so special about words?

Readers are sensitive to the statistics of written language. New work by Vidal et al. suggests that this sensitivity may be driven by the same domain-general mechanisms that enable the visual system to detect statistical regularities in the visual environment. 

Highlights

• Readers presented with orthographic-like stimuli are sensitive to bigram frequencies 

• An analogous effect emerges with images of made-up objects and visual gratings 

• These data suggest that the reading system might rely on general-purpose mechanisms 

• This calls for considering reading in the broader context of visual neuroscience

Summary

As writing systems are a relatively novel invention (slightly over 5 kya), they could not have influenced the evolution of our species. Instead, reading might recycle evolutionary older mechanisms that originally supported other tasks and preceded the emergence of written language. Accordingly, it has been shown that baboons and pigeons can be trained to distinguish words from nonwords based on orthographic regularities in letter co-occurrence. This suggests that part of what is usually considered reading-specific processing could be performed by domain-general visual mechanisms. Here, we tested this hypothesis in humans: if the reading system relies on domain-general visual mechanisms, some of the effects that are often found with orthographic material should also be observable with non-orthographic visual stimuli. We performed three experiments using the same exact design but with visual stimuli that progressively departed from orthographic material. Subjects were passively familiarized with a set of composite visual items and tested in an oddball paradigm for their ability to detect novel stimuli. Participants showed robust sensitivity to the co-occurrence of features (“bigram” coding) with strings of letter-like symbols but also with made-up 3D objects and sinusoidal gratings. This suggests that the processing mechanisms involved in the visual recognition of novel words also support the recognition of other novel visual objects. These mechanisms would allow the visual system to capture statistical regularities in the visual environment. We hope that this work will inspire models of reading that, although addressing its unique aspects, place it within the broader context of vision.

Useful Delusions

I want to pass on to MindBlog readers some background information on the recent book "Useful Delusions: The Power and Paradox of the Self-Deceiving Brain" by Shankar Vedantam, host of NPR’s “The Hidden Brain,” and science writer Bill Mesler. It was compiled by a member of the four person program committee of the Austin Rainbow Forum discussion group to which I belong.

This Hidden Brain podcast interview with Shankar Vedantum is a great resource for those up to the challenge of sitting in a comfortable chair for an hour listening to a great conversation while enjoying a pleasant beverage.

And here are a few alternatives for the listening challenged:

A book excerpt at the Hidden Brain website.

And, book reviews from The New York Journal of Books, and The Wall Street Journal.

Why does passion matter more in individualistic cultures?

Tsai does an interesting commentary  (open source) on work noted in MindBlog's recent post on an article by Li et al.  Some clips:

Our research finds that, because achieving independence requires increased arousal and action, cultures that foster these goals value high-arousal positive states like passion, excitement, and enthusiasm. In contrast, because achieving interdependence requires decreased arousal and action, cultures that foster these goals value low-arousal positive states like calm, peacefulness, and balance.

These ideals matter because people use them to judge their own feelings, and, perhaps even more importantly, to judge the feelings of others. For instance, because European Americans value excitement more than Hong Kong Chinese, they rate “excited” faces (with broad toothy smiles) as much friendlier and warmer than “calm” faces (with closed smiles), compared to Hong Kong Chinese. And, because European Americans perceive excited (vs. calm) faces as friendlier and warmer, they share more money with excited vs. calm partners in economic games (e.g., the Dictator Game), compared to East Asians.

Experiencing and expressing cultural ideals can have life-altering consequences in the real world. When deciding whom to lend to on a web-based microlending platform (Kiva.com), people from countries with an excitement ideal loaned more to borrowers who had “excited” smiles in their profile photos and less to borrowers who had “calm” smiles. In a business setting, when selecting an intern, European Americans viewed the “ideal applicant” as being more excited (vs. calm), and chose more excited (vs. calm) applicants than Hong Kong Chinese did. Even in health settings, European Americans chose excitement-focused physicians who promoted dynamic lifestyles (vs. calm-focused physicians who promoted relaxing lifestyles) more than Hong Kong Chinese did. Interestingly, European Americans also recalled and adhered to the recommendations of the excitement- versus calm-focused physician more than East Asian Americans did. These findings suggest that people may also be more receptive to the advice and feedback of people who express their cultural ideal.

...in the context of a European American focus on passion, calm East Asian Americans are often inaccurately judged to be “cold” and “stoic” . This may explain why, compared to European Americans, East Asian Americans are less likely to be promoted to top leadership positions, a problem often described as “the Bamboo Ceiling”. But this might be avoided if teachers, employers, and other decision makers in individualistic cultures understood that in many cultures — as illustrated by the findings of Li et al. — passion matters less. Instead of passion, people are finding, following, and fueling calm, balance, and the other affective states that their cultures value more.

The Psychology of Fake News

Pennycook and Rand do a fascinating open source article in Trends in Cognitive Science on the psychology of fake news.  Their highlights and summary: 

Recent evidence contradicts the common narrative that partisanship and politically motivated reasoning explain why people fall for 'fake news'. 

Poor truth discernment is linked to a lack of careful reasoning and relevant knowledge, as well as to the use of familiarity and source heuristics. 

There is also a large disconnect between what people believe and what they will share on social media, and this is largely driven by inattention rather than by purposeful sharing of misinformation. 

Effective interventions can nudge social media users to think about accuracy, and can leverage crowdsourced veracity ratings to improve social media ranking algorithms.

We synthesize a burgeoning literature investigating why people believe and share false or highly misleading news online. Contrary to a common narrative whereby politics drives susceptibility to fake news, people are ‘better’ at discerning truth from falsehood (despite greater overall belief) when evaluating politically concordant news. Instead, poor truth discernment is associated with lack of careful reasoning and relevant knowledge, and the use of heuristics such as familiarity. Furthermore, there is a substantial disconnect between what people believe and what they share on social media. This dissociation is largely driven by inattention, more so than by purposeful sharing of misinformation. Thus, interventions can successfully nudge social media users to focus more on accuracy. Crowdsourced veracity ratings can also be leveraged to improve social media ranking algorithms.

How dopamine leads to hallucinations

Hallucinations (perceptual experiences without external stimuli) seen in conditions such as schizophrenia are thought to result from giving too much weight to priors, creating an imbalance at the expense of actual sensory evidence. Sustained high-dopamine tone in the striatum has been proposed to contribute to this imbalance; however, it has remained unclear how the dopaminergic perturbation leads to the generation of hallucinations. Schmack et al. have developed a cross-species computational psychiatry approach to directly relate human and rodent behavior and used this approach to study the neural basis of hallucination-like perception in mice. Here is the summary of their results and their conclusion:   

RESULTS

We set up analogous auditory detection tasks for humans and mice. Both humans and mice were presented with an auditory stimulus in which a tone signal was embedded in a noisy background on half of the trials. Humans pressed one of two buttons to report whether or not they heard a signal, whereas mice poked into one of two choice ports. Humans indicated how confident they were in their report by positioning a cursor on a slider; mice expressed their confidence by investing variable time durations to earn a reward. In humans, hallucination-like percepts—high-confidence false alarms—were correlated with the tendency to experience spontaneous hallucinations, as quantified by a self-report questionnaire. In mice, hallucination-like percepts increased with two manipulations known to induce hallucinations in humans: administration of ketamine and the heightened expectation of hearing a signal. We then used genetically encoded dopamine sensors with fiber photometry to monitor dopamine dynamics in the striatum. We found that elevations in dopamine levels before stimulus onset predicted hallucination-like perception in both the ventral striatum and the tail of the striatum. We devised a computational model that explains the emergence of hallucination-like percepts as a consequence of faulty perceptual inference when prior expectations outweigh sensory evidence. Our model clarified how hallucination-like percepts can arise from fluctuations in two distinct types of expectations: reward expectations and perceptual expectations. In mice, dopamine fluctuations in the ventral striatum reflected reward expectations, whereas in the tail of the striatum they resembled perceptual expectations. We optogenetically boosted dopamine in the tail of the striatum and observed that increasing dopamine induced hallucination-like perception. This effect was rescued by the administration of haloperidol, an antipsychotic drug that blocks D2 dopamine receptors.

CONCLUSION

We established hallucination-like perception as a quantitative behavior in mice for modeling the subjective experience of a cardinal symptom of psychosis. We found that hallucination-like perception is mediated by dopamine elevations in the striatum and that this can be explained by encoding different kinds of expectations in distinct striatal subregions. These findings support the idea that hallucinations arise as faulty perceptual inferences due to elevated dopamine producing a bias in favor of prior expectations against current sensory evidence. Our results also yield circuit-level insights into the long-standing dopamine hypothesis of psychosis and provide a rigorous framework for dissecting the neural circuit mechanisms involved in hallucinations. We propose that this approach can guide the development of novel treatments for schizophrenia and other psychotic disorders.

A Dendrite-Focused Framework for Understanding the Actions of Ketamine and Psychedelics

I pass on the highlioght points from an interesting review (open source, with a useful graphic) of how the similar therapeutic effects of ketamine and psychedelics might be explained:

Ketamine can relieve symptoms of depression and anxiety, therefore filling a critically unmet psychiatric need. A few small-scale clinical studies suggest serotonergic psychedelics may have similar therapeutic effects.

Ketamine may both enhance and suppress dendritic excitability, through microcircuit interactions involving disinhibition.

Serotonergic psychedelics may both enhance and suppress excitability, through targeting coexpressed receptors.

Spatial mismatch in the opposing drug actions on dendritic excitability is predicted to steer plasticity actions towards certain synapses and cell types.

We present a dendrite-focused framework as a novel lens to view the actions of ketamine and serotonergic psychedelics on cortical circuits.

False memories can be reversed without damage to true memories.

 Oeberst et al.  demonstrate the effectiveness of source sensitization, which involves alerting participants that their memories could come from external sources, and false memory sensitization, which involves informing individuals that repeatedly being asked to recollect events can produce false memories. The two strategies could be widely implemented in real-world settings and do not require interviewers to know any ground truths.:  

Significance

Human memory is fallible and malleable. In forensic settings in particular, this poses a challenge because people may falsely remember events with legal implications that never actually happened. Despite an urgent need for remedies, however, research on whether and how rich false autobiographical memories can be reversed under realistic conditions (i.e., using reversal strategies that can be applied in real-world settings) is virtually nonexistent. The present study therefore not only replicates and extends previous demonstrations of false memories but, crucially, documents their reversibility after the fact: Employing two ecologically valid strategies, we show that rich but false autobiographical memories can mostly be undone. Importantly, reversal was specific to false memories (i.e., did not occur for true memories).

Abstract

False memories of autobiographical events can create enormous problems in forensic settings (e.g., false accusations). While multiple studies succeeded in inducing false memories in interview settings, we present research trying to reverse this effect (and thereby reduce the potential damage) by means of two ecologically valid strategies. We first successfully implanted false memories for two plausible autobiographical events (suggested by the students’ parents, alongside two true events). Over three repeated interviews, participants developed false memories (measured by state-of-the-art coding) of the suggested events under minimally suggestive conditions (27%) and even more so using massive suggestion (56%). We then used two techniques to reduce false memory endorsement, source sensitization (alerting interviewees to possible external sources of the memories, e.g., family narratives) and false memory sensitization (raising the possibility of false memories being inadvertently created in memory interviews, delivered by a new interviewer). This reversed the false memory build-up over the first three interviews, returning false memory rates in both suggestion conditions to the baseline levels of the first interview (i.e., to ∼15% and ∼25%, respectively). By comparison, true event memories were endorsed at a higher level overall and less affected by either the repeated interviews or the sensitization techniques. In a 1-y follow-up (after the original interviews and debriefing), false memory rates further dropped to 5%, and participants overwhelmingly rejected the false events. One strong practical implication is that false memories can be substantially reduced by easy-to-implement techniques without causing collateral damage to true memories.

The case against reality

Over the past year I've dipped into and out of Donald Hoffman's ideas several times, looking back at Geffer's article in Granta Magazine, Hoffman's TED talk, and sections of his 2019 book "The Case Against Reality: Why Evolution Hid the Truth from Our Eyes." Mainly for my future reference (I forget things, and use my MindBlog posts to go back and look them up), I'm attempting to put down the bare bones of his arguments with a selection of clips from these various sources.

As we go about our daily lives, we tend to assume that our perceptions — sights, sounds, textures, tastes — are an accurate portrayal of the real world...If they were not, wouldn’t evolution have weeded us out by now?...This hunch is wrong. On the contrary, our perceptions of snakes and apples, and even of space and time, do not reveal objective reality...It is a theorem of evolution by natural selection that wallops our hunches.

Does natural selection really favor seeing reality as it is? Fortunately, we don't have to wave our hands and guess; evolution is a mathematically precise theory. We can use the equations of evolution to check this out. We can have various organisms in artificial worlds compete and see which survive and which thrive, which sensory systems are more fit. A key notion in those equations is fitness...Fitness is not the same thing as reality as it is, and it's fitness, and not reality as it is, that figures centrally in the equations of evolution... we have run hundreds of thousands of evolutionary game simulations with lots of different randomly chosen worlds and organisms that compete for resources in those worlds. Some of the organisms see all of the reality, others see just part of the reality, and some see none of the reality, only fitness. Who wins? ...perception of reality goes extinct. In almost every simulation, organisms that see none of reality but are just tuned to fitness drive to extinction all the organisms that perceive reality as it is. So the bottom line is, evolution does not favor veridical, or accurate perceptions. Those perceptions of reality go extinct. Fitness beats truth (This is the "FBT theorem").

A metaphor can help our intuitions. Suppose you’re writing an email, and the icon for its file is blue, rectangular, and in the center of your desktop. Does this mean that the file itself is blue, rectangular, and in the center of your computer? Of course not...The purpose of a desktop interface is not to show you the “truth” of the computer—where “truth," in this metaphor, refers to circuits, voltages, and layers of software. Rather, the purpose of an interface is to hide the “truth” and to show simple graphics that help you perform useful tasks such as crafting emails and editing photos. If you had to toggle voltages to craft an email, your friends would never hear from you. That is what evolution has done. It has endowed us with senses that hide the truth and display the simple icons we need to survive long enough to raise offspring... Perception is not a window on objective reality. It is an interface that hides objective reality behind a veil of helpful icons...Evolution has shaped our senses to keep us alive. We have to take them seriously: if you see a speeding Maserati, don’t leap in front of it; if you see a moldy apple, don’t eat it. But it is a mistake of logic to assume that if we must take our senses seriously then we are required—or even entitled—to take them literally.

We used to think that the Earth is flat because it looks that way. Then we thought that the Earth is the unmoving center of reality because it looks that way. We were wrong. We had misinterpreted our perceptions. Now we believe that spacetime and objects are the nature of reality as it is. The theory of evolution is telling us that once again, we're wrong. We're misinterpreting the content of our perceptual experiences. There's something that exists when you don't look, but it's not spacetime and physical objects. It's...hard for us to let go of spacetime and objects...we're blind to our own blindnesses...By peering through the lens of a telescope we discovered that the Earth is not the unmoving center of reality, and by peering through the lens of the theory of evolution we discovered that spacetime and objects are not the nature of reality. When I have a perceptual experience that I describe as a red tomato, I am interacting with reality, but that reality is not a red tomato and is nothing like a red tomato...And here's the kicker: When I have a perceptual experience that I describe as a brain, or neurons, I am interacting with reality, but that reality is not a brain or neurons and is nothing like a brain or neurons. And that reality, whatever it is, is the real source of cause and effect in the world -- not brains, not neurons. Brains and neurons have no causal powers. They cause none of our perceptual experiences, and none of our behavior. Brains and neurons are a species-specific set of symbols, a hack.

Plasticity during our development of mapping time on to space.

A previous mindblog post has pointed to work showing how culture shapes our spatial conceptions of time. Starr and Srinivasan now address the development of spatial representations of time in three dimension in children from different cultures.:

Across cultures, people frequently communicate about time in terms of space. English speakers in the United States, for example, might “look forward” to the future or gesture toward the left when talking about the past. As shown by these examples, different dimensions of space are used to represent different temporal concepts. Here, we explored how cultural factors and individual differences shape the development of two types of spatiotemporal representations in 6- to 15-year-old children: the horizontal/vertical mental timeline (in which past and future events are placed on a horizontal or vertical line that is external to the body) and the sagittal mental timeline (in which events are placed on a line that runs through the front-back axis of the body). We tested children in India because the prevalence of both horizontal and vertical calendars there provided a unique opportunity to investigate how calendar orientation and writing direction might each influence the development of the horizontal/vertical mental timeline. Our results suggest that the horizontal/vertical mental timeline and the sagittal mental timeline are constructed in parallel throughout childhood and become increasingly aligned with culturally-conventional orientations. Additionally, we show that experience with calendars may influence the orientation of children's horizontal/vertical mental timelines, and that individual differences in children's attitudes toward the past and future may influence the orientation of their sagittal mental timelines. Taken together, our results demonstrate that children are sensitive to both cultural and personal factors when building mental models of time.

Measuring happiness in small steps.

I find this Brook's self help essay - that I came across while browsing the news during this morning's coffee - to be a nice brief tonic. His basic message is that small steps are more likely to make you happier than hard-to-achieve lifelong goals. I pass on his three summary nostrums here and recommend that you scan his list of brief essays on "How to build a life" in the Atlantic Magazine.  

1. Live in “day-tight compartments.”

The scientific literature is clear that goals can bring a lot of happiness when they are short term, achievable, and leading us toward ultimate success—in other words, when achieving them indicates that we are making progress...set an end goal, then break it into manageable steps: one year, one month, one week, one day.

2. Focus on the journey.

...see major goals not as the only way to achieve happiness but as points of navigation that set a direction for your lifelong journey. That way, when storms arise and new opportunities present themselves, you can set a new goal and gracefully let go of your old one, thereby avoiding disappointment and missed opportunities.

3. Set intrinsic goals.

Extrinsic goals — money, power, and prestige — can be the hardest to achieve because they are inherently zero-sum: In the pursuit of scarce resources, we crowd one another out. By contrast, intrinsic goals—based on love and personal growth—are positive-sum, and thus more likely to lead to success: My efforts to love and grow as a person are not crowded by your efforts; on the contrary, they can be complementary...they are the goals most associated with happiness...intrinsic goals are akin to what the writer David Brooks calls “eulogy virtues”: the things you would want people to remember you for at the end of your life.

Brain mechanism by which testosterone reduces generosity

 Interesting work from Jianxin Ou et al.:

Significance

Testosterone is associated with aggressive behavior in both animals and humans. Here, we establish a link between increased testosterone and selfishness in economic decision making and identify the neural mechanisms through which testosterone reduces generosity in a double-blind, placebo-controlled, between-participant study. We find that testosterone induces more selfish choices, particularly when distant others are concerned. Moreover, it disrupts the representation of other-regarding value in local activity and functional connectivity involving the temporoparietal junction and subcortical regions involved in reward processing. Our study provides causal evidence for a testosterone-mediated neurohormonal link between generosity and the valuation system.

Abstract

Recent evidence has linked testosterone, a major sex hormone, to selfishness in economic decision-making. Here, we aimed to investigate the neural mechanisms through which testosterone reduces generosity by combining functional MRI with pharmacological manipulation among healthy young males in a double-blind, placebo-controlled, between-subject design. After testosterone or placebo gel administration, participants performed a social discounting task in which they chose between selfish options (benefiting only the participant) and generous options (providing also some benefit to another person at a particular social distance). At the behavioral level, testosterone reduced generosity compared to the placebo. At the neural level (n = 60), the temporoparietal junction (TPJ) encoded the other-regarding value of the generous option during generous choices, and this effect was attenuated by testosterone, suggesting that testosterone reduced the consideration of other’s welfare as underpinned by TPJ activity. Moreover, TPJ activity more strongly reflected individual differences in generosity in the placebo than the testosterone group. Furthermore, testosterone weakened the relation between the other-regarding value of generous decisions and connectivity between the TPJ and a region extending from the insula into the striatum. Together, these findings suggest that a network encompassing both cortical and subcortical components underpins the effects of testosterone on social preferences.

Four distinct patterns of aging - what is your 'ageotype'?

An interesting piece from Lanese describs work showing how aging unfolds at different rates in different tissues:

The research team behind the study sorted 43 people into aging categories, or "ageotypes," based on biological samples collected over the course of two years. The samples included blood, inflammatory substances, microbes, genetic material, proteins and by-products of metabolic processes. By tracking how the samples changed over time, the team identified about 600 so-called markers of aging — values that predict the functional capacity of a tissue and essentially estimate its "biological age."

So far, the team has identified four distinct ageotypes: Immune, kidney, liver and metabolic. Some people fit squarely in one category, but others may meet the criteria for all four, depending on how their biological systems hold up with age.

Expanding the study will surely reveal more than four categories. One of the study participants was clearly a cardiovascular ager, whose cardiac muscle was accumulating damage at a greater rate than other parts of their body. 

This reminds me of Atul Gawande's great description of how complex systems wear down and crash:

...complex systems—power plants, say—have to survive and function despite having thousands of critical components. Engineers therefore design these machines with multiple layers of redundancy: with backup systems, and backup systems for the backup systems. The backups may not be as efficient as the first-line components, but they allow the machine to keep going even as damage accumulates...within the parameters established by our genes, that’s exactly how human beings appear to work. We have an extra kidney, an extra lung, an extra gonad, extra teeth. The DNA in our cells is frequently damaged under routine conditions, but our cells have a number of DNA repair systems. If a key gene is permanently damaged, there are usually extra copies of the gene nearby. And, if the entire cell dies, other cells can fill in.

Nonetheless, as the defects in a complex system increase, the time comes when just one more defect is enough to impair the whole, resulting in the condition known as frailty. It happens to power plants, cars, and large organizations. And it happens to us: eventually, one too many joints are damaged, one too many arteries calcify. There are no more backups. We wear down until we can’t wear down anymore.

Points on having a self and free will.

 A recent podcast by Sam Harris summarizing his ideas on the question of whether we have free will motivates me to do a further summary here…

There is a broad consensus among many disciplines that our experience of having a self or “I” is an illusion (see for example my lecture “The I-Illusion” and subsequent web lectures).  This self illusion is what has the experience of ‘free will,’ of being free to make choices. Having a self is other side of the coin of having free will.

Here is my one paragraph paraphrase of points that Sam Harris’ makes in his ‘Waking Up’ App, and book of that title, as well as his recent podcast:

We all are concatenations of previous causes with the most recent proximal cause rising from this subconscious mist.  What we take to be our 'self' or 'I' is actually the archive of our past actions and experiences, stored in long term declarative and procedural memory systems from which thoughts and actions of the present instant  seem to rise from nowhere - 'we' don't 'choose' them, they just seem to appear.  Having morality doesn't require free will, it is accomplished by having a historical coltlective record of what actions do or don't work out well, with respect to holding society together and passing on our genes. Thinking that 2 + 2 = 5 or killing other humans have bad consequences.  It is from this history of actions and expectations in our brain that the moral choices of the moment arise, again as if from nowhere.

Still, most of us, even if granting the above, can’t imagine losing our feeling of having a self, it seems too useful, we couldn’t get along without it.  This problem is addressed at the end of my “I-Illusion” talk with text based on points Wegner makes at the end of his classic 2002 book “The Illusion of Conscious Will” : 

…..the important point is that we have the experience of having free will, and it must be there for something, even if it is not an adequate theory of behavior causation....perhaps we have conscious will because it helps us to appreciate and remember what we are doing, the experience of will marks our actions for us, its embodied quality our actions from those of other agents in our environment.

We have evolved emotions of anger, sadness, fear, happiness related to survival. We can think of the emotion of agency, or conscious will, as the same sort of evolved emotion, obviously a useful capability in sorting out our physical and social world. 

The authorship emotion, an emotion that authenticates the action's owner as the self, is something we would miss if it were gone... it would not be very satisfying to go through life causing things, making discoveries, helping people, whatever.. if we had no personal recognition of those achievements.

And, this view doesn't really need to conflict with notions of responsibility and morality, because what people intend and consciously will is a basis for how the moral rightness or wrongness of an act judged. This is why mental competence is an issue in criminal trials.

So, just as in theater, art, used car sales ...and in the scientific analysis of conscious will..how things seem is more important than what they are. It seems to us that we have selves, have conscious will, have minds, are agents. While it is sobering and ultimately accurate to call all this an illusion, it is incorrect to call the illusion a trivial one, its invention has an obvious evolutionary rationale (along with long list of cognitive biases we seem to be hardwired with). Illusions piled on top of apparent mental causation are the building blocks of human psychology, social life, and our dominance as a species on this planet.

Passion matters but not equally everywhere.

From Li et al.:  

Significance

In three large-scale datasets representing adolescents from 59 societies across the globe, we find evidence of a systematic cultural variation in the relationship between passion and achievement. In individualistic societies, passion better predicts achievement and explains more variance in achievement outcomes. In collectivistic societies, passion still positively predicts achievement, but it is a much less powerful predictor. There, parents’ support predicts achievement as much as passion. One implication of these findings is that if admission officers, recruiters, and managers rely on only one model of motivation, a Western independent one, they may risk passing over and mismanaging talented students and employees who increasingly come from sociocultural contexts where a more interdependent model of motivation is common and effective.

Abstract

How to identify the students and employees most likely to achieve is a challenge in every field. American academic and lay theories alike highlight the importance of passion for strong achievement. Based on a Western independent model of motivation, passionate individuals—those who have a strong interest, demonstrate deep enjoyment, and express confidence in what they are doing—are considered future achievers. Those with less passion are thought to have less potential and are often passed over for admission or employment. As academic institutions and corporations in the increasingly multicultural world seek to acquire talent from across the globe, can they assume that passion is an equally strong predictor of achievement across cultural contexts? We address this question with three representative samples totaling 1.2 million students in 59 societies and provide empirical evidence of a systematic, cross-cultural variation in the importance of passion in predicting achievement. In individualistic societies where independent models of motivation are prevalent, relative to collectivistic societies where interdependent models of motivation are more common, passion predicts a larger gain (0.32 vs. 0.21 SD) and explains more variance in achievement (37% vs. 16%). In contrast, in collectivistic societies, parental support predicts achievement over and above passion. These findings suggest that in addition to passion, achievement may be fueled by striving to realize connectedness and meet family expectations. Findings highlight the risk of overweighting passion in admission and employment decisions and the need to understand and develop measures for the multiple sources and forms of motivation that support achievement.

Hierarchical dynamics as a macroscopic organizing principle of the human brain

Raut, Snyder, and Raichle do a open source description of general principles describing the functional organization of brain activity timescales that vary according to anatomical hierarchy:  

Significance

Accumulating evidence suggests that, during task performance, information is encoded at shorter timescales in primary sensory regions as compared to longer timescales in higher-order cortical regions. These encoding timescales correlate with the timescales of activity within these regions. Here, we test the hypothesis that a hierarchy of activity timescales represents a general organizing principle of brain function. Using functional imaging of the human brain in the eyes-open resting state, we find that the timescales of ongoing activity are hierarchically organized as gradients across the entire cerebral cortex. Further, whole-brain coverage permitted examination of subcortical structures, which exhibited hierarchical timescale gradients parallel to cerebral cortex. Altogether, our results support the existence of hierarchical gradients that globally organize human brain dynamics.

Abstract

Multimodal evidence suggests that brain regions accumulate information over timescales that vary according to anatomical hierarchy. Thus, these experimentally defined “temporal receptive windows” are longest in cortical regions that are distant from sensory input. Interestingly, spontaneous activity in these regions also plays out over relatively slow timescales (i.e., exhibits slower temporal autocorrelation decay). These findings raise the possibility that hierarchical timescales represent an intrinsic organizing principle of brain function. Here, using resting-state functional MRI, we show that the timescale of ongoing dynamics follows hierarchical spatial gradients throughout human cerebral cortex. These intrinsic timescale gradients give rise to systematic frequency differences among large-scale cortical networks and predict individual-specific features of functional connectivity. Whole-brain coverage permitted us to further investigate the large-scale organization of subcortical dynamics. We show that cortical timescale gradients are topographically mirrored in striatum, thalamus, and cerebellum. Finally, timescales in the hippocampus followed a posterior-to-anterior gradient, corresponding to the longitudinal axis of increasing representational scale. Thus, hierarchical dynamics emerge as a global organizing principle of mammalian brains.

How about another global conspiracy theory?..... Multinational mega-corporations are a global oligarchy maintaining world peace.

I pass on this great clip from Mark Manson's weekly newletter:

Watch any cheesy Hollywood action flick from the 90s or early 2000s and the villain is likely some mega-billionaire who’s about to destroy half a nation and all the baby seals along with it because it’ll add a few more percentage points to his bottom line.

Peruse any conspiracy theory forum or YouTube channel (note: please don’t actually do this) and you’ll come across dozens of half-baked theories about how governments are secretly controlled by the Big Evil Corporation and all these people are being killed on purpose so that Bill Gates can like, add a third wing to his mansion… or something.

(Sidenote: If I ever start another business, I’m totally going to call it “Big Evil Corporation.”)

But what if I told you these same too-big-to-fail companies might be the best thing happening for global peace? The idea is not as crazy as you think.

Some version of this idea was first proposed in 1995 by the economist Thomas Friedman in what he initially called “The Golden Arches Theory of Conflict.” The theory was simple: two countries with McDonald’s restaurants had, until then, never gone to war with one another and Friedman aruged that they would rarely, if ever, go to war in the future.

His reasoning was that two countries that enjoy the fruits of globalized, American-exported schlop would never jeopardize such luxuries by opting to kill each other instead.

Unfortunately for Friedman, it only took a few years for two ethnic groups to discover that they hated each other way more than they liked Big Macs, as the Bosnia and Serbia war quickly put an end to that theory.

But like any good human, Friedman learned from his mistakes and updated his theory in 2005 to the new and improved “Dell Theory of Conflict.” The Dell Theory says that any two countries who share supply chains for major industries with one another would never go to war, as the economic disruption would make any conflict too costly to pursue.

Unlike its cheap McDonald’s cousin, The Dell Theory of Conflict seems to have some legs to it. It explains why India and Pakistan keep backing down from each other, why China always says it’s going to invade Taiwan but never does, and why the US really has only seemed interested in invading countries that don’t have anything interesting to sell them.

People rarely believe this, but we live in the most peaceful period of human history. The world has not experienced a large-scale war between two major powers in over 50 years. Wars have been declining for so long and have become so rare that foreign policy experts have come to refer to the last fifty years as “The Long Peace.”

Last year, I wrote that a company like Apple is likely more responsible for peace between the US and China than any US president. Neither country wants to fuck with a $2 trillion dollar cash cow in both their backyards.

We’ve more recently seen this with the pandemic. Pharmaceutical companies who were once at each other’s throats came together and shared research and manufacturing capacity because they all realized that a world in enforced lockdowns isn’t good for anybody.

Hell, you want to get into conspiracies? Blackrock, the largest financial asset management in the world, with over $8 trillion dollars in assets, and tentacles in every industry and almost every country, has allegedly picked up the phone before and politely asked various groups and countries to knock it off and start selling to each other. And, well, I guess there’s something to that?

Economic self-interest may be soulless. But perhaps by removing people’s group affinities and emotional biases from the equation, at scale, it does make for a better, safer world.

Traces of psychedelics make you feel good, but so does placebo.

From Balázs Szigeti et al.:

Microdosing is the practice of regularly using low doses of psychedelic drugs. Anecdotal reports suggest that microdosing enhances well-being and cognition; however, such accounts are potentially biased by the placebo effect. This study used a ‘self-blinding’ citizen science initiative, where participants were given online instructions on how to incorporate placebo control into their microdosing routine without clinical supervision. The study was completed by 191 participants, making it the largest placebo-controlled trial on psychedelics to-date. All psychological outcomes improved significantly from baseline to after the 4 weeks long dose period for the microdose group; however, the placebo group also improved and no significant between-groups differences were observed. Acute (emotional state, drug intensity, mood, energy, and creativity) and post-acute (anxiety) scales showed small, but significant microdose vs. placebo differences; however, these results can be explained by participants breaking blind. The findings suggest that anecdotal benefits of microdosing can be explained by the placebo effect.

Further descriptions and discussions of this work are offered by Cameron and by O'Grady.