MindBlog gets an extreme comment on Covid

I've debated on whether it would be better to ignore (and not amplify by passing on) an extreme comment of a sort MindBlog almost never receives. It is sent as a response to, but does not actually comment on, last Wednesday's post on the David Brooks article "What Happened to American Conservatism."  Although I am in complete disagreement with the comment's content, I've decided to pass it on because  it is an instructive example of the quality, style, stance and arguments of a fraction of America's population large enough to guarantee the continued generation of Covid variants that will maintain Covid as a chronic disease for the foreseeable future.  Here's the comment:

Re the "the human condition"... The TRUE human condition or world we live in is about 2 pink elephants in the room and has never been on clearer display than with the deliberate global Covid Scam atrocity — check out “The 2 Married Pink Elephants In The Historical Room –The Holocaustal Covid-19 Coronavirus Madness: A Sociological Perspective & Historical Assessment Of The Covid “Phenomenon”” at w w w d o t CovidTruthBeKnown d o t c o m 

“[…] when you do things to people against their will and force them it destroys their spirit, it destroys the integrity of their body. […]. Being an adult is meaningless if you cannot even protect the integrity of your own body.” -- Jennifer Daniels, MD, MBA, Holistic Doctor 

If your employer (even educational or federal employers) wants you to take a Covid vaccine give him/her one of these form letters of exemption found at w w w d o t lc d o t o r g/exempt 

By the way, with the letters of "omicron" an alleged Covid variant you can spell "moronic"...

And further speaking of stupid herd people not getting the glaringly obvious truth/ie not getting the constant onslaught of BIG lies of the official authorities, the world we live in and what the human condition is really is encapsulated in the following reality... 

"2 weeks to flatten the curve has turned into...3 shots to feed your family!" --- Unknown

A musical offering.

For this day that was central in my Protestant Christian Texas childhood: a performance by the Netherlands Bach Society of the Gloria in Excelsis Deo from Bach's  Christmas Cantata BVW 191 first performed in Leipzig ~1742. There is joy in this music that transcends it’s religious origins. 

What Happened to American Conservatism?

I want to strongly recommed that you read David Brooks' article on conservatism in the January/February 2022 issue of The Atlantic. I read slowly though it three times, think it makes a compelling summary of our current political quandry, and wish that it offered more insight into possible ways out of our current predicament as we watch what seems to be an unstopable slippage back to pre-Enlightenment mentalities. Just a few clips of text towards the end of the piece:

...perhaps the biggest reason for conservatism’s decay into Trumpism was spiritual. The British and American strains of conservatism were built on a foundation of national confidence...By 2016, that confidence was in tatters. Communities were falling apart, families were breaking up, America was fragmenting. Whole regions had been left behind, and many elite institutions had shifted sharply left and driven conservatives from their ranks. Social media had instigated a brutal war of all against all, social trust was cratering, and the leadership class was growing more isolated, imperious, and condescending. “Morning in America” had given way to “American carnage” and a sense of perpetual threat.

...a pessimistic shadow conservatism has always lurked in the darkness, haunting the more optimistic, confident one. The message this shadow conservatism conveys is the one that Trump successfully embraced in 2016: Evil outsiders are coming to get us. But in at least one way, Trumpism is truly anti-conservative. Both Burkean conservatism and Lockean liberalism were trying to find ways to gentle the human condition, to help society settle differences without resort to authoritarianism and violence. Trumpism is pre-Enlightenment. Trumpian authoritarianism doesn’t renounce holy war; it embraces holy war, assumes it is permanent, in fact seeks to make it so. In the Trumpian world, disputes are settled by raw power and intimidation. The Trumpian epistemology is to be anti-epistemology, to call into question the whole idea of truth, to utter whatever lie will help you get attention and power. Trumpism looks at the tender sentiments of sympathy as weakness. Might makes right.

...the populist and nationalist forces are rising. All of life is seen as an incessant class struggle between oligarchic elites and the common volk. History is a culture-war death match. Today’s mass-market, pre-Enlightenment authoritarianism is not grateful for the inherited order but sees menace pervading it: You’ve been cheated. The system is rigged against you. Good people are dupes. Conspiracists are trying to screw you. Expertise is bogus. Doom is just around the corner. I alone can save us.

Trumpian Republicanism plunders, degrades, and erodes institutions for the sake of personal aggrandizement. The Trumpian cause is held together by hatred of the Other. Because Trumpians live in a state of perpetual war, they need to continually invent existential foes—critical race theory, nongendered bathrooms, out-of-control immigration. They need to treat half the country, metropolitan America, as a moral cancer, and view the cultural and demographic changes of the past 50 years as an alien invasion. Yet pluralism is one of America’s oldest traditions; to conserve America, you have to love pluralism. As long as the warrior ethos dominates the GOP, brutality will be admired over benevolence, propaganda over discourse, confrontation over conservatism, dehumanization over dignity. A movement that has more affection for Viktor Orbán’s Hungary than for New York’s Central Park is neither conservative nor American. This is barren ground for anyone trying to plant Burkean seedlings.

I’m content, as my hero Isaiah Berlin put it, to plant myself instead on the rightward edge of the leftward tendency—in the more promising soil of the moderate wing of the Democratic Party. If its progressive wing sometimes seems to have learned nothing from the failures of government and to promote cultural stances that divide Americans, at least the party as a whole knows what year it is. In 1980, the core problem of the age was statism, in the form of communism abroad and sclerotic, dynamism-sapping bureaucracies at home. In 2021, the core threat is social decay. The danger we should be most concerned with lies in family and community breakdown, which leaves teenagers adrift and depressed, adults addicted and isolated. It lies in poisonous levels of social distrust, in deepening economic and persisting racial disparities that undermine the very goodness of America—in political tribalism that makes government impossible.

To reduce the economic chasm that separates class from class, to ease the financial anxiety that renders life unstable for many people, to support parenting so that children can grow up with more stability—these are the goals of a party committed to ameliorating, not exploiting, a growing sense of hopelessness and alienation, of vanishing opportunity. Daniel Patrick Moynihan’s brilliant dictum—which builds on a Burkean wisdom forged in a world of animosity and corrosive flux—has never been more worth heeding than it is now: The central conservative truth is that culture matters most; the central liberal truth is that politics can change culture.

The Point is to Stop - a farewell to self help coaching

I want to pass on some points, paraphrase, and central clips from what is essentially a swan song offered by Mark Manson in his latest newsletter - a newsletter whose contents I have mentioned in a number of previous MindBlog posts. This Manson essay hits me between the eyes, because I'm very aware that one of my main motivations for doing this MindBlog since Feb. 2006, with it's 5,220 posts (and counting) is that it has turned out to be valuable self therapy for Deric (with this abstracting of Manson's current article being one example). 

He begins by referencing an older article noting that 

...the best way to judge the usefulness of self-help advice is by now many people eventually leave it behind.

He notes that people who seek out self help..

...do so with two different mindsets... the "Doctor People" ...look to a book, website or seminar to cure their emotional ails... the "Coach People"...want a mentor or coach..They want strategies, roadmaps, to know the right moves...the problem is that Doctor People see personal growth as information that is to be learned rather than a skill that must be practiced...Self-awareness, managing emotions, empathy, vulnerability are skills ..it can take years to become somewhat good at them... Coach People are in it for the long haul.

But what the Coach People don't get is that the whole point is to eventually stop. It's to leave. Because unlike chess or basketball, there's no world championship for anger management. Nobody is going to give you a trophy for mindfulness...the skill curves are different...In basketball or chess, the better you get, the more effort is required to further improve...in personal growth, the better you get, the less effort is required to further improve...personal growth skills have positive feedback loops bakes into them.. like skiing downhill..it takes a lot of effort to get some speed going, but once you're on your way, the most effective thing you can do to gain speed is nothing.

...what the Coach People miss is that the whole point of this stuff, the way to 'win,' is to one day be free of consciously having to think about it...At some point, you just have to live your damn life...Coach People who identify as the "personal growth" not only get trapped by it, but are likely to bore you at dinner parties with their stories about their ayahuasca retreats.

And, at this point in the article, Mason declares that he is going to leave behind his career as a Coach Person, move on from the self help world he started writing a blog about in 2008, the blog being his own therapy as "I tried to sort through my own shit." 

And now,

I'm no longer the guy at the top of the ski hill struggling to get going. I feel like the guy flying down, full speed ahead..to continue writing about these topics feels like unnecessarily planting my poles into the snow...the standard roadmap for self-help authors when they produce a hit book is to spend the next 20-30 years regurgitating the same ideas over and over again in various formats, on various stages, cashing the checks as they go. To me that sounds about as interesting as sticking my dick in a light socket...I've spent a lot of the past few years anxious and insecure that I would "lose my audience," by stepping away from self-help content. It's taken me way too long to listen to my own advice and just not give a fuck.

Manson then describes how he plans to leave behind a repository (The Subtle Art School) of what he has worked so hard to learn the past ten years, and leave his blog as an archive for posterity. 

The active grandparent hypothesis

Lieberman et al. suggest that selection in humans for lifelong physical activity, including during postreproductive years to provision offspring, promoted selection for energy allocation pathways which synergistically slow senescence and reduce vulnerability to many forms of chronic diseases. Here is their abstract (motivated readers can obtain a copy of the article from me):

The proximate mechanisms by which physical activity (PA) slows senescence and decreases morbidity and mortality have been extensively documented. However, we lack an ultimate, evolutionary explanation for why lifelong PA, particularly during middle and older age, promotes health. As the growing worldwide epidemic of physical inactivity accelerates the prevalence of noncommunicable diseases among aging populations, integrating evolutionary and biomedical perspectives can foster new insights into how and why lifelong PA helps preserve health and extend lifespans. Building on previous life-history research, we assess the evidence that humans were selected not just to live several decades after they cease reproducing but also to be moderately physically active during those postreproductive years. We next review the longstanding hypothesis that PA promotes health by allocating energy away from potentially harmful overinvestments in fat storage and reproductive tissues and propose the novel hypothesis that PA also stimulates energy allocation toward repair and maintenance processes. We hypothesize that selection in humans for lifelong PA, including during postreproductive years to provision offspring, promoted selection for both energy allocation pathways which synergistically slow senescence and reduce vulnerability to many forms of chronic diseases. As a result, extended human healthspans and lifespans are both a cause and an effect of habitual PA, helping explain why lack of lifelong PA in humans can increase disease risk and reduce longevity.

New articles on exercise and the brain

Gretchen Reynolds has done two recent brief reviews:

 The Quiet Brain of the Athlete describes work showing that the brains of fit, young athletes dial down extraneous noise and attend to important sounds better than those of other young people. 

And, 

 Staying physically active may protect the aging brain. Simple activities like walking boost immune cells in the brain that may help to keep memory sharp and even ward off Alzheimer’s disease.

Temporal Self-Compression

Brietzke and Meyer (open source) provide behavioral and neural evidence that our past and future selves are compressed as they move away from the present:  

Significance

For centuries, great thinkers have struggled to understand how people represent a personal identity that changes over time. Insight may come from a basic principle of perception: as objects become distant, they also become less discriminable or “compressed.” In Studies 1–3, we demonstrate that people’s ratings of their own personality become increasingly less differentiated as they consider more distant past and future selves. In Study 4, we found neural evidence that the brain compresses self-representations with time as well. When we peer out a window, objects close to us are in clear view, whereas distant objects are hard to tell apart. We provide evidence that self-perception may operate similarly, with the nuance of distant selves increasingly harder to perceive.

Abstract

A basic principle of perception is that as objects increase in distance from an observer, they also become logarithmically compressed in perception (i.e., not differentiated from one another), making them hard to distinguish. Could this basic principle apply to perhaps our most meaningful mental representation: our own sense of self? Here, we report four studies that suggest selves are increasingly non-discriminable with temporal distance from the present as well. In Studies 1 through 3, participants made trait ratings across various time points in the past and future. We found that participants compressed their past and future selves, relative to their present self. This effect was preferential to the self and could not be explained by the alternative possibility that individuals simply perceive arbitrary self-change with time irrespective of temporal distance. In Study 4, we tested for neural evidence of temporal self-compression by having participants complete trait ratings across time points while undergoing functional MRI. Representational similarity analysis was used to determine whether neural self-representations are compressed with temporal distance as well. We found evidence of temporal self-compression in areas of the default network, including medial prefrontal cortex and posterior cingulate cortex. Specifically, neural pattern similarity between self-representations was logarithmically compressed with temporal distance. Taken together, these findings reveal a “temporal self-compression” effect, with temporal selves becoming increasingly non-discriminable with distance from the present.

Severity and clinical course of depression correlates with altered connectivity in sensorimotor cortices.

Interesting work from Ray et al.,  

Significance

Research into neurobiology of depression primarily focuses on its complex psychological aspects. Here we propose an alternative approach and target sensorimotor alterations—a prominent but often neglected feature of depression. We demonstrated using resting-state functional MRI data and computational modeling that top-down and bottom-up information flow in sensory and motor cortices is altered with increasing depression severity in a way that is consistent with depression symptoms. Depression-associated changes were found to be consistent across sessions, amenable to treatment and of effect size sufficiently large to predict whether somebody has mild or severe depression. These results pave the way for an avenue of research into the neural underpinnings of mental health conditions.

Abstract

Functional neuroimaging research on depression has traditionally targeted neural networks associated with the psychological aspects of depression. In this study, instead, we focus on alterations of sensorimotor function in depression. We used resting-state functional MRI data and dynamic causal modeling (DCM) to assess the hypothesis that depression is associated with aberrant effective connectivity within and between key regions in the sensorimotor hierarchy. Using hierarchical modeling of between-subject effects in DCM with parametric empirical Bayes we first established the architecture of effective connectivity in sensorimotor cortices. We found that in (interoceptive and exteroceptive) sensory cortices across participants, the backward connections are predominantly inhibitory, whereas the forward connections are mainly excitatory in nature. In motor cortices these parities were reversed. With increasing depression severity, these patterns are depreciated in exteroceptive and motor cortices and augmented in the interoceptive cortex, an observation that speaks to depressive symptomatology. We established the robustness of these results in a leave-one-out cross-validation analysis and by reproducing the main results in a follow-up dataset. Interestingly, with (nonpharmacological) treatment, depression-associated changes in backward and forward effective connectivity partially reverted to group mean levels. Overall, altered effective connectivity in sensorimotor cortices emerges as a promising and quantifiable candidate marker of depression severity and treatment response.

The Science of Mind Reading

James Somers offers a fascinating article in the Nov. 29 issue of The New Yorker, which I recommend that you read. It describes the development of the technique of Latent Semantic Analysis (L.S.A) originating in the work of a psychologist named Charles Osgood nearly 70 years ago and now being applied to the analysis of fMRI recordings from people to infer what they are internally thinking or seeing.

In 2013, researchers at Google unleashed a descendant of it onto the text of the whole World Wide Web. Google’s algorithm turned each word into a “vector,” or point, in high-dimensional space. The vectors generated by the researchers’ program, word2vec, are eerily accurate: if you take the vector for “king” and subtract the vector for “man,” then add the vector for “woman,” the closest nearby vector is “queen.” Word vectors became the basis of a much improved Google Translate, and enabled the auto-completion of sentences in Gmail. Other companies, including Apple and Amazon, built similar systems. Eventually, researchers realized that the “vectorization” made popular by L.S.A. and word2vec could be used to map all sorts of things. Today’s facial-recognition systems have dimensions that represent the length of the nose and the curl of the lips, and faces are described using a string of coördinates in “face space.” Chess A.I.s use a similar trick to “vectorize” positions on the board. The technique has become so central to the field of artificial intelligence that, in 2017, a new, hundred-and-thirty-five-million-dollar A.I. research center in Toronto was named the Vector Institute. Matthew Botvinick, a professor at Princeton whose lab was across the hall from Norman’s, and who is now the head of neuroscience at DeepMind, Alphabet’s A.I. subsidiary, told me that distilling relevant similarities and differences into vectors was “the secret sauce underlying all of these A.I. advances.”

 

Subsequent sections of the article describe how machine learning has been brought to brain imaging with voxels of neural activity serving as dimensions in a kind of thought space.

...today’s thought-decoding researchers mostly look for specific thoughts that have been defined in advance. But a “general-purpose thought decoder,” Norman told me, is the next logical step for the research. Such a device could speak aloud a person’s thoughts, even if those thoughts have never been observed in an fMRI machine. In 2018, Botvinick, Norman’s hall mate, co-wrote a paper in the journal Nature Communications titled “Toward a Universal Decoder of Linguistic Meaning from Brain Activation.” Botvinick’s team had built a primitive form of what Norman described: a system that could decode novel sentences that subjects read silently to themselves. The system learned which brain patterns were evoked by certain words, and used that knowledge to guess which words were implied by the new patterns it encountered.

In praise of Sheeple - why we shouldn't always think for ourselves

A friend pointed out this interesting article by Ian Leslie, which I recommend that you read. I pass on a few clips at the end of his exposition:

...the human instinct to copy rather than think for ourselves is good for us, up to a point. Cultural anthropologists have done the most to establish that our instinct to copy parents and peers helps us to learn, to get along, to organise, to bond, and ultimately to build the shared behaviours that enable us to survive and progress. They’ve discovered that compared to other primates humans “over-imitate”: we copy even when there’s no reason to.

In a much-replicated experiment, a complicated-looking box is presented to chimps and the researchers demonstrate how to access a bit of food inside. They include some unnecessary steps: tapping the box three times, fiddling with a bolt, whatever. The chimps quickly work out all they need to do is pull a door and grab the food, and ignore the superfluous actions. Do this experiment with very small humans, however, and the kids copy all the actions. The chimps are more efficient and in a way more ‘rational’ but it’s the other primate which has built cities, ships and cathedrals.

Traditions we don’t understand ought not to be dismissed too quickly, since the collective intelligence of the past dwarves our own. In The Secret of Our Success, the anthropologist Joseph Henrich argues that individual humans are not nearly as smart as we think and that it is culture that makes us a successful species. The Naskapi, a foraging tribe from north-eastern Canada, hunt caribou. They have to decide where to hunt, which isn’t straightforward because if they visit one location too often the caribou know to stay away. The best hunting strategy therefore requires randomisation.

But individuals like to think they’re smart and left to their own devices, Naskapi hunters probably wouldn’t be satisfied with setting out in a random direction every day; they’d come up with brilliant plans which proved to be disastrous. Tradition saves them. To decide where to go, the hunters use a divination ritual which involves heating a caribou shoulder blade over hot coals until cracks and spots start to appear on it; the resulting pattern is then used as a map. In a sense it’s a mindless ritual, but it’s also a randomising device which helps the hunters overcome their decision-making biases.

Here’s what I like about the dupes. When everyone around them behaved in a certain way, their first thought wasn’t “I must be smarter than them”. It was, “They must know something I don’t”. There is an admirable humility to that, even if, in this case, it led them to say or do something absurd. The ability of individual humans to think for ourselves is crucial to progress; equally crucial is that we trust, sometimes unthinkingly, in judgements made by others, alive or dead. Societies where too few people are willing to question norms and traditions tend to stagnate and to perpetuate injustices. But there is a positive side to conformism, too. Just as in an imaginary nightclub on fire there’s a good chance that a passing group will lead you to an exit, there’s a good chance that whatever the people around you say is right, is right, even if you don’t fully understand why yet. Society functions best when we’re sheepish.

What is a DAO? Who needs humans?

A DAO is a Decentralised Autonomous Organisation. My son pointed out this intriguing and also somewhat terrifying video to me. Like Mark Zuckerberg's corporate "Meta" fantasies another step towards tearing our evolved biolgical bodies and social brains away from the organic tactile contacts with each other for which they were designed.

 

The Science of Hugs?

Schultz describes an entertaining bit of work pursuing the obvious done by Düren et.al. Guys hugging each other use their arms differently than women do, more frequently doing a crisscross hug (on the left) than a neck-waist hug (on the right), most likely because the neck-waist hug feels a bit more intimate.

Without prompting the students on how to hug, the researchers found the crisscross style was more common, accounting for 66 out of 100 hugs. The preference for crisscross was especially prevalent in pairs of men, with 82% of 28 observed pairs opting for the style. Neither emotional closeness nor height had significant effects on the style of hugging; however, the researchers note that most participants were relatively close in height, and they guess that neck-waist might be more common when heights differ more drastically.

Cannabis use during pregnancy correlates with cortisol, anxiety, aggression, and hyperactivity in young children.

Sobering results from Rompala et al.: 

Significance

Cannabis use is becoming more prevalent, including during developmentally sensitive periods such as pregnancy. Here we find that maternal cannabis use is associated with increased cortisol, anxiety, aggression, and hyperactivity in young children. This corresponded with widespread reductions in immune-related gene expression in the placenta which correlated with anxiety and hyperactivity. Future studies are needed to examine the effects of cannabis on immune function during pregnancy as a potential regulatory mechanism shaping neurobehavioral development.

Abstract

While cannabis is among the most used recreational drugs during pregnancy, the impact of maternal cannabis use (mCB) on fetal and child development remains unclear. Here, we assessed the effects of mCB on psychosocial and physiological measures in young children along with the potential relevance of the in utero environment reflected in the placental transcriptome. Children (∼3 to 6 y) were assessed for hair hormone levels, neurobehavioral traits on the Behavioral Assessment System for Children (BASC-2) survey, and heart rate variability (HRV) at rest and during auditory startle. For a subset of children with behavioral assessments, placental specimens collected at birth were processed for RNA sequencing. Hair hormone analysis revealed increased cortisol levels in mCB children. In addition, mCB was associated with greater anxiety, aggression, and hyperactivity. Children with mCB also showed a reduction in the high-frequency component of HRV at baseline, reflecting reduced vagal tone. In the placenta, there was reduced expression of many genes involved in immune system function including type I interferon, neutrophil, and cytokine-signaling pathways. Finally, several of these mCB-linked immune genes organized into coexpression networks that correlated with child anxiety and hyperactivity. Overall, our findings reveal a relationship between mCB and immune response gene networks in the placenta as a potential mediator of risk for anxiety-related problems in early childhood.

An artificial neural network that responds to written words like our brain's word form area

Interesting work from Dehaene and collaborators:  

Significance

Learning to read results in the formation of a specialized region in the human ventral visual cortex. This region, the visual word form area (VWFA), responds selectively to written words more than to other visual stimuli. However, how neural circuits at this site implement an invariant recognition of written words remains unknown. Here, we show how an artificial neural network initially designed for object recognition can be retrained to recognize words. Once literate, the network develops a sparse neuronal representation of words that replicates several known aspects of the cognitive neuroscience of reading and leads to precise predictions concerning how a small set of neurons implement the orthographic stage of reading acquisition using a compositional neural code.

Abstract

The visual word form area (VWFA) is a region of human inferotemporal cortex that emerges at a fixed location in the occipitotemporal cortex during reading acquisition and systematically responds to written words in literate individuals. According to the neuronal recycling hypothesis, this region arises through the repurposing, for letter recognition, of a subpart of the ventral visual pathway initially involved in face and object recognition. Furthermore, according to the biased connectivity hypothesis, its reproducible localization is due to preexisting connections from this subregion to areas involved in spoken-language processing. Here, we evaluate those hypotheses in an explicit computational model. We trained a deep convolutional neural network of the ventral visual pathway, first to categorize pictures and then to recognize written words invariantly for case, font, and size. We show that the model can account for many properties of the VWFA, particularly when a subset of units possesses a biased connectivity to word output units. The network develops a sparse, invariant representation of written words, based on a restricted set of reading-selective units. Their activation mimics several properties of the VWFA, and their lesioning causes a reading-specific deficit. The model predicts that, in literate brains, written words are encoded by a compositional neural code with neurons tuned either to individual letters and their ordinal position relative to word start or word ending or to pairs of letters (bigrams).

Online spread of false information depends on cascade size

Juul and Ugander do an analysis of factors that influence the spread of false news, finding a central role for cascade size and suggesting that to limit the spread of false news, it may be enough to focus on reducing the mean “infectiousness” of the information.  

Significance

Do different types of information spread differently online? In recent years, studies have sought answers to such questions by comparing statistical properties of network paths taken by different kinds of content diffusing online. Here, we demonstrate the importance of controlling for correlations between properties being compared. In particular, we show that previously reported structural differences between diffusion paths of false and true news on Twitter disappear when comparing only cascades of the same size; differences between diffusion paths of images, videos, news, and petitions persist. Paired with a theoretical analysis of diffusion processes, our results suggest that, in order to limit the spread of false news, it may be enough to focus on reducing the mean “infectiousness” of the information.

Abstract

Do some types of information spread faster, broader, or further than others? To understand how information diffusions differ, scholars compare structural properties of the paths taken by content as it spreads through a network, studying so-called cascades. Commonly studied cascade properties include the reach, depth, breadth, and speed of propagation. Drawing conclusions from statistical differences in these properties can be challenging, as many properties are dependent. In this work, we demonstrate the essentiality of controlling for cascade sizes when studying structural differences between collections of cascades. We first revisit two datasets from notable recent studies of online diffusion that reported content-specific differences in cascade topology: an exhaustive corpus of Twitter cascades for verified true- or false-news content by Vosoughi et al. [S. Vosoughi, D. Roy, S. Aral. Science 359, 1146–1151 (2018)] and a comparison of Twitter cascades of videos, pictures, news, and petitions by Goel et al. [S. Goel, A. Anderson, J. Hofman, D. J. Watts. Manage. Sci. 62, 180–196 (2016)]. Using methods that control for joint cascade statistics, we find that for false- and true-news cascades, the reported structural differences can almost entirely be explained by false-news cascades being larger. For videos, images, news, and petitions, structural differences persist when controlling for size. Studying classical models of diffusion, we then give conditions under which differences in structural properties under different models do or do not reduce to differences in size. Our findings are consistent with the mechanisms underlying true- and false-news diffusion being quite similar, differing primarily in the basic infectiousness of their spreading process.

Caution around the fountain of youth.

Lee et al. do a review "Antiaging diets: Separating fact from fiction" in Science Magazine. The link takes you to their summary, abstract, and a nice graphic. I pass on a Box 1 from the body of the article titled "reclaiming the term 'anti-aging'":

The phrase “antiaging” is greatly abused in popular culture, often for the purpose of marketing cosmetic procedures or unproven nutritional supplements purported to slow or reverse aging. This has the unfortunate consequence of creating confusion among the general public and diminishing the impact of legitimate scientific discovery. Here, we define “antiaging” as delaying or reversing biological aging by targeting the established molecular mechanisms of aging, which have been formalized as “hallmarks” or “pillars” of aging (93, 94). Effective antiaging interventions in laboratory animals increase both median and maximum population life span and broadly delay the onset and progression of many age-related functional declines and diseases. The latter effect is often referred to as “extending health span,” which is a qualitative term referring to the period of life free from chronic disease and disability (95). Recent studies show that at least some antiaging interventions, such as the drug rapamycin, can reverse functional declines across multiple tissues in aged animals (96). On the basis of this definition, there are as yet no clinically validated antiaging interventions in humans. However, there is some evidence consistent with antiaging effects for CR and related diets in humans as well as a small number of putative geroprotective compounds, including metformin and rapamycin (97).

93. C. López-Otín, M. A. Blasco, L. Partridge, M. Serrano, G. Kroemer, The hallmarks of aging. Cell 153, 1194–1217 (2013).

94. B. K. Kennedy, S. L. Berger, A. Brunet, J. Campisi, A. M. Cuervo, E. S. Epel, C. Franceschi, G. J. Lithgow, R. I. Morimoto, J. E. Pessin, T. A. Rando, A. Richardson, E. E. Schadt, T. Wyss-Coray, F. Sierra, Geroscience: Linking aging to chronic disease. Cell 159, 709–713 (2014).

95 M. Kaeberlein, How healthy is the healthspan concept? Geroscience 40, 361–364 (2018).

96 R. Selvarani, S. Mohammed, A. Richardson, Effect of rapamycin on aging and age-related diseases-past and future. Geroscience 43, 1135–1158 (2021).

97 M. B. Lee, M. Kaeberlein, Translational Geroscience: From invertebrate models to companion animal and human interventions. Transl. Med. Aging 2, 15–29 (2018).

Volatile hexadecanal emitted by babies could make men more docile and women more aggressive

Interesting observations from Mishor et al.:

In terrestrial mammals, body volatiles can effectively trigger or block conspecific aggression. Here, we tested whether hexadecanal (HEX), a human body volatile implicated as a mammalian-wide social chemosignal, affects human aggression. 

Using validated behavioral paradigms, we observed a marked dissociation: Sniffing HEX blocked aggression in men but triggered aggression in women. Next, using functional brain imaging, we uncovered a pattern of brain activity mirroring behavior: In both men and women, HEX increased activity in the left angular gyrus, an area implicated in perception of social cues. HEX then modulated functional connectivity between the angular gyrus and a brain network implicated in social appraisal (temporal pole) and aggressive execution (amygdala and orbitofrontal cortex) in a sex-dependent manner consistent with behavior: increasing connectivity in men but decreasing connectivity in women. These findings implicate sex-specific social chemosignaling at the mechanistic heart of human aggressive behavior.

From the author's discussion:

....what behavioral setting could underlie selection for a body volatile that increases aggression in women but decreases it in men? Or in other words, what could be the ecological relevance of these results? In this respect, we call attention to the setting of infant rearing. Parents across cultures are encouraged to sniff their babies, an action that activates brain reward circuits in women. Our results imply that sniffing babies may increase aggression in mothers but decrease aggression in fathers. Whereas maternal aggression has a direct positive impact on offspring survival in the animal world, paternal aggression has a negative impact on offspring survival. This is because maternal aggression (also termed maternal defense behavior) is typically directed at intruders, yet paternal aggression, and more so nonpaternal male aggression, is often directed at the offspring themselves. If babies had a mechanism at their disposal that increased aggression in women but decreased it in men, this would likely increase their survival. With the hypothesis in mind that HEX provides babies with exactly such a mechanism, we first note that infant rearing is the one social setting where humans have extensive exposure to conspecific feces, a rich source of HEX. We also turned to a recently published analysis of baby-head volatiles, yet in contrast to our hypothesis, this report did not mention HEX. We turned to the authors of that report, who explained that the published analysis was not tuned to the near semivolatile range of HEX. With our question in mind, they (now coauthors T.U. and M.O.) sampled an additional 19 babies, using gas chromatography (GC) × GC–mass spectrometry, and observed that HEX is one of the most abundant baby-head volatiles...

Socrates, Diderot, and Wolpert on Writing and Printing

I have to pass on these quotes sent by one my Chaos and Complexity Seminar colleagues at the University of Wisconsin:

Socrates on writing, from Phaedrus, 275a-b

"For this invention will produce forgetfulness in the minds of those who learn to use it, because they will not practice their memory. Their trust in writing, produced by external characters which are no part of themselves, will discourage the use of their own memory within them. You have invented an elixir not of memory, but of reminding; and you offer your pupils the appearance of wisdom, not true wisdom, for they will read many things without instruction and will therefore seem to know many things, when they are for the most part ignorant and hard to get along with, since they are not wise, but only appear wise."

Denis Diderot, Encyclopédie, 1755

"As long as the centuries continue to unfold, the number of books will grow continually, and one can predict that a time will come when it will be almost as difficult to learn anything from books as from the direct study of the whole universe. It will be almost as convenient to search for some bit of truth concealed in nature as it will be to find it hidden away in an immense multitude of bound volumes."

Lewis Wolpert (1929--2021) Lewis Wolpert - Scientist - Web of Stories

"Reading rots the mind."

Fluid intelligence and the locus coeruleus-norepinephrine system

Tsukahara and Engle suggest that the cognitive mechanisms of fluid intelligence map onto the locus coeruleus–norepinephrine system. I pass on their introductory paragraph (the link takes you to their abstract, which I think is less informative):

In this article, we outline what we see as a potentially important relationship for understanding the biological basis of intelligence: that is, the relationship between fluid intelligence and the locus coeruleus–norepinephrine system. This is largely motivated by our findings that baseline pupil size is related to fluid intelligence; the larger the pupils, the higher the fluid intelligence. The connection to the locus coeruleus is based on research showing that the size of the pupil can be used as an indicator of locus coeruleus activity. A large body of research on the locus coeruleus–norepinephrine system in animal and human studies has shown how this system is critical for an impressively wide range of behaviors and cognitive processes, from regulating sleep/wake cycles, to sensation and perception, attention, learning and memory, decision making, and more. The locus coeruleus–norepinephrine system achieves this primarily through its widespread projection system throughout the cortex, strong connections with the prefrontal cortex, and the effect of norepinephrine at many levels of brain function. Given the broad role of this system in behavior, cognition, and brain function, we propose that the locus coeruleus–norepinephrine system is essential for understanding the biological basis of intelligence.

Drifting nerve assemblies can maintain persistent memories

A prevailing model has been that a memory in our brains is stored in a specific set of nerve connections, that, like a book in a library, stays where it belongs. Over the past few years, however, it has become more and more clear that 'representational plasticity' may be the norm. A recent article by Kossio et al. proposes a contrasting memory model (motivated readers can obtain the whole article from me):

Change is ubiquitous in living beings. In particular, the connectome and neural representations can change. Nevertheless, behaviors and memories often persist over long times. In a standard model, associative memories are represented by assemblies of strongly interconnected neurons. For faithful storage these assemblies are assumed to consist of the same neurons over time. Here we propose a contrasting memory model with complete temporal remodeling of assemblies, based on experimentally observed changes of synapses and neural representations. The assemblies drift freely as noisy autonomous network activity and spontaneous synaptic turnover induce neuron exchange. The gradual exchange allows activity-dependent and homeostatic plasticity to conserve the representational structure and keep inputs, outputs, and assemblies consistent. This leads to persistent memory. Our findings explain recent experimental results on temporal evolution of fear memory representations and suggest that memory systems need to be understood in their completeness as individual parts may constantly change.

Here is an explanatory graphic from the article:

Assembly drift and persistent memory. (A) At two nearby times a similar ensemble of neurons forms the neural representation of, for example, “apple” (compare the blue-colored assembly neurons at the first and the second time point). At distant times the representation consists of completely different ensembles (blue-colored assembly neurons at the first and the third time point). Due to their gradual change, temporally distant representations are indirectly related via ensembles in the time period between them. (B) Parts of a thread possess the same form of indirect relation: Nearby parts are composed of similar ensembles of fibers, while distant ones consist of different ensembles, which are connected by those in between. (C) The complete change of memory representations still allows for stable behavior. In the schematic, a tasty apple is perceived. At different times, this triggers different ensembles that presently form the representation of “apple”; see A. Assembly activation initiates a reaching movement toward the apple, despite the dissimilarity of the activated neuron ensembles. Memory and behavior are conserved because the gradual change of assembly neurons enables the inputs (green) and outputs (orange) to track the neural representation.