Locus Coeruleus integrity and memory in aging adults

The locus coeruleus is a deep brain nucleus whose cells synthesize noradrenaline that is sent via its axonal projections to other parts of the brain. Hämmerer et al. show that its integrity is critical in maintaining memory performance:

Significance

Locus coeruleus (LC) integrity in cognitively normal older adults is a potentially important preclinical marker in dementia. Our study establishes a link between variability in LC integrity and cognitive decline related to noradrenergic modulation in old age. We find that in older adults, reduced LC integrity explains lower memory performance. This effect was more pronounced for memory related to negative events, and accompanied by increased pupil diameter size in response to negative events. The study provides a strong motivation for future research investigating the role of LC integrity in healthy, as well as in pathological, aging.

Abstract

The locus coeruleus (LC) is the principal origin of noradrenaline in the brain. LC integrity varies considerably across healthy older individuals, and is suggested to contribute to altered cognitive functions in aging. Here we test this hypothesis using an incidental memory task that is known to be susceptible to noradrenergic modulation. We used MRI neuromelanin (NM) imaging to assess LC structural integrity and pupillometry as a putative index of LC activation in both younger and older adults. We show that older adults with reduced structural LC integrity show poorer subsequent memory. This effect is more pronounced for emotionally negative events, in accord with a greater role for noradrenergic modulation in encoding salient or aversive events. In addition, we found that salient stimuli led to greater pupil diameters, consistent with increased LC activation during the encoding of such events. Our study presents novel evidence that a decrement in noradrenergic modulation impacts on specific components of cognition in healthy older adults. The findings provide a strong motivation for further investigation of the effects of altered LC integrity in pathological aging.

A.I. quantifies 100 years of gender and ethnic stereotypes.

Hutson points to work of Garg et al. that uses artificial intelligence to demonstrate how racial and gender stereotypes have changed over time.

They designed their program to use word embeddings, strings of numbers that represent a word’s meaning based on its appearance next to other words in large bodies of text. If people tend to describe women as emotional, for example, “emotional” will appear alongside “woman” more frequently than “man,” and word embeddings will pick that up...Going decade by decade, they found that words related to competence—such as “resourceful” and “clever”—were slowly becoming less masculine. But words related to physical appearance—such as “alluring” and ”homely”—were stuck in time...their embeddings were still distinctly “female.”...Asian names became less tightly linked to terms for outsiders...words related to terrorism became more closely associated with words related to Islam...

Here is the Carg et al. abstract:

Word embeddings are a powerful machine-learning framework that represents each English word by a vector. The geometric relationship between these vectors captures meaningful semantic relationships between the corresponding words. In this paper, we develop a framework to demonstrate how the temporal dynamics of the embedding helps to quantify changes in stereotypes and attitudes toward women and ethnic minorities in the 20th and 21st centuries in the United States. We integrate word embeddings trained on 100 y of text data with the US Census to show that changes in the embedding track closely with demographic and occupation shifts over time. The embedding captures societal shifts—e.g., the women’s movement in the 1960s and Asian immigration into the United States—and also illuminates how specific adjectives and occupations became more closely associated with certain populations over time. Our framework for temporal analysis of word embedding opens up a fruitful intersection between machine learning and quantitative social science.

The contract with authoritarianism

Thomas Edsall offers yet another of his thoughtful well referenced essays, from which I want to pass on a few clips. You should read the entire article. He begins by citing a quote from George Lakoff’s writing, done just after the 1994 Newt Gingrich Republican revolution that led to our current era of conservative ascendancy:

Deeply embedded in conservative and liberal politics are two different models of the family. Conservatism is based on a Strict Father model, while liberalism is centered on a Nurturant Parent model. These two models of the family give rise to different moral systems.

…The crucial word now… is authoritarianism.

The election of Donald Trump — built as it was on several long-term trends that converged in 2016 — has created an authoritarian moment. 

…traits like closed mindedness, along with aversion to change and discomfort with diversity, are linked to authoritarianism:

As these social and cultural conflicts have become a bigger part of our political debates, citizens have sorted into different parties based on personality, with citizens high in openness much more likely to be liberals and Democrats than those low in openness. This psychological sorting process does not line up perfectly with older partisan differences based on class, because those higher in income and education also tend to be higher in openness.

With the rise of cultural and lifestyle politics, Democrats and Republicans are now sharply distinguished by a set of psychological dispositions related to experiential openness — a general dimension of personality tapping tolerance for threat and uncertainty in one’s environment.

Edall cites Marc Hetherington and Jonathan Weiler:

...preferences about many of the new issues on the American political agenda, such as gay rights, the war in Iraq, the proper response to terrorism, and immigration are likely structured by authoritarianism.

Those with a fixed worldview tend to see “American Carnage,” while those with fluid worldviews see the world as a big, beautiful place that is safe to explore. The fixed tend to be wary of what they perceive as constant threats to their physical security specifically and of social change in general. The fluid are much more open to change and, indeed, see it as a strength. For them, anger lies in holding on to old ideas and rejecting diversity.

Matt Grossmann and Daniel Thaler of Michigan State University further expand on the role of psychological traits in voter decision-making in their forthcoming paper, “Mass-Elite Divides in Aversion to Social Change and Support for Donald Trump.” They found that aversion to change “is strongly predictive of support for Trump” among regular voters, but much less so among Republican political elites.

Smith and Hanley used what they call a “domineering leader scale” to measure the wish for a strong leader who will force others to submit. The premise is that evil is afoot; that money, the media and government authority — and even “politically correct” moral authority — have been usurped by undeserving interlopers. The desire for a domineering leader is the desire to see this evil crushed.

If an aggressive, domineering authoritarianism is a prime motivator for many Trump supporters, as Smith and Hanley contend, the clash between Republicans and Democrats is likely to become more hostile and warlike.

Federico, Feldman and Weber note that:

...since the early 2000s, many especially acrimonious political debates have focused on threats to social stability and order — debates surrounding abortion, transgender rights, immigration, and the role of the federal government in protecting the rights of marginalized social groups.

The rising “salience of these debates,” they write, “has contributed to a growing ‘authoritarian divide’ within the United States, at least among White Americans.”

Trump has purposefully exacerbated the “many especially acrimonious political debates” now dominating public discourse, deepening not only the authoritarian divide, but the divide between open and closed mindedness, between acceptance and racial resentment, and between toleration of and aversion to change. He evidently believes that this is the best political strategy for presiding in the White House and winning re-election, but it is an extraordinarily destructive strategy for governing the country and for safeguarding America’s interests in the world.

A small molecule for stroke therapy

The small 'magic molecule,' a neural plasticity enhancer, found by Abe et al. to accelerate motor function recovery from brain damage is edonerpic maleate, whose complicated formal name I won't spell out here, but instead show you the structure:

Here is their abstract:

Brain damage such as stroke is a devastating neurological condition that may severely compromise patient quality of life. No effective medication-mediated intervention to accelerate rehabilitation has been established. We found that a small compound, edonerpic maleate, facilitated experience-driven synaptic glutamate AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic-acid) receptor delivery and resulted in the acceleration of motor function recovery after motor cortex cryoinjury in mice in a training-dependent manner through cortical reorganization. Edonerpic bound to collapsin-response-mediator-protein 2 (CRMP2) and failed to augment recovery in CRMP2-deficient mice. Edonerpic maleate enhanced motor function recovery from internal capsule hemorrhage in nonhuman primates. Thus, edonerpic maleate, a neural plasticity enhancer, could be a clinically potent small compound with which to accelerate rehabilitation after brain damage.

And, Rumpel offers a nice summary graphic in his perspectives piece describing the work (click to enlarge):

Why senior adults get lost more frequently than younger adults.

Strang et al. identify the brain area whose degeneration with aging underlies the loss of our navigational abilities:

Highlights

•Grid-cell-like representations in human entorhinal cortex are compromised in old age 

•This effect is predominantly driven by a lack of representational stability over time 

•Path integration ability in old age is associated with grid-cell-like representations

Summary

A progressive loss of navigational abilities in old age has been observed in numerous studies, but we have only limited understanding of the neural mechanisms underlying this decline. A central component of the brain’s navigation circuit are grid cells in entorhinal cortex, largely thought to support intrinsic self-motion-related computations, such as path integration (i.e., keeping track of one’s position by integrating self-motion cues). Given that entorhinal cortex is particularly vulnerable to neurodegenerative processes during aging and Alzheimer’s disease, deficits in grid cell function could be a key mechanism to explain age-related navigational decline. To test this hypothesis, we conducted two experiments in healthy young and older adults. First, in an fMRI experiment, we found significantly reduced grid-cell-like representations in entorhinal cortex of older adults. Second, in a behavioral path integration experiment, older adults showed deficits in computations of self-position during path integration based on body-based or visual self-motion cues. Most strikingly, we found that these path integration deficits in older adults could be explained by their individual magnitudes of grid-cell-like representations, as reduced grid-cell-like representations were associated with larger path integration errors. Together, these results show that grid-cell-like representations in entorhinal cortex are compromised in healthy aging. Furthermore, the association between grid-cell-like representations and path integration performance in old age supports the notion that grid cells underlie path integration processes. We therefore conclude that impaired grid cell function may play a key role in age-related decline of specific higher-order cognitive functions, such as spatial navigation.

We choose what we want to hear.

Billig et al. provide a nice example of how we can consciously influence what we perceive, in this case hearing a sequence of pure tones either as individual sounds or as an integrated percept: 

SIGNIFICANCE STATEMENT

Can we consciously influence our perception of the external world? We address this question using sound sequences that can be heard either as coming from a single source or as two distinct auditory streams. Listeners reported spontaneous changes in their perception between these two interpretations while we recorded neural activity to identify signatures of such integration and segregation. They also indicated that they could, to some extent, choose between these alternatives. This claim was supported by corresponding changes in responses in auditory cortex. By linking neural and behavioral correlates of perception, we demonstrate that the number of objects that we perceive can depend not only on the physical attributes of our environment, but also on how we intend to experience it.

Abstract

Auditory signals arrive at the ear as a mixture that the brain must decompose into distinct sources based to a large extent on acoustic properties of the sounds. An important question concerns whether listeners have voluntary control over how many sources they perceive. This has been studied using pure high (H) and low (L) tones presented in the repeating pattern HLH-HLH-, which can form a bistable percept heard either as an integrated whole (HLH-) or as segregated into high (H-H-) and low (-L-) sequences. Although instructing listeners to try to integrate or segregate sounds affects reports of what they hear, this could reflect a response bias rather than a perceptual effect. We had human listeners (15 males, 12 females) continuously report their perception of such sequences and recorded neural activity using MEG. During neutral listening, a classifier trained on patterns of neural activity distinguished between periods of integrated and segregated perception. In other conditions, participants tried to influence their perception by allocating attention either to the whole sequence or to a subset of the sounds. They reported hearing the desired percept for a greater proportion of time than when listening neutrally. Critically, neural activity supported these reports; stimulus-locked brain responses in auditory cortex were more likely to resemble the signature of segregation when participants tried to hear segregation than when attempting to perceive integration. These results indicate that listeners can influence how many sound sources they perceive, as reflected in neural responses that track both the input and its perceptual organization.

Reprogramming fear responses outside of conscious awareness.

Fascinating work by Taschereau-Dumouchel et al. suggests that our 'hard wired' fear responses can be reprogrammed or attenuated by an unconscious manipulation, offering an alternative to the common exposure therapies that are often aversive to patients.

Significance

Conventional therapies for the treatment of anxiety disorders are aversive, and as a result, many patients terminate treatment prematurely. We have developed an unconscious method to bypass the unpleasantness in conscious exposure using functional magnetic resonance imaging neural reinforcement. Using this method, participants learn to generate brain patterns similar to the multivariate brain pattern of a feared animal. We demonstrate in a double-blind placebo-controlled experiment that neural reinforcement can lead to reliable reductions in physiological fear responses. Crucially, this intervention can be achieved completely unconsciously and without any aversive reaction. Extending our approach to other forms of psychopathologies, such as posttraumatic stress disorders, might eventually provide another means of intervention for patients currently receiving insufficient exposure treatments.

Abstract

Can “hardwired” physiological fear responses (e.g., for spiders and snakes) be reprogramed unconsciously in the human brain? Currently, exposure therapy is among the most effective treatments for anxiety disorders, but this intervention is subjectively aversive to patients, causing many to drop out of treatment prematurely. Here we introduce a method to bypass the subjective unpleasantness in conscious exposure, by directly pairing monetary reward with unconscious occurrences of decoded representations of naturally feared animals in the brain. To decode physiological fear representations without triggering excessively aversive reactions, we capitalize on recent advancements in functional magnetic resonance imaging decoding techniques, and use a method called hyperalignment to infer the relevant representations of feared animals for a designated participant based on data from other “surrogate” participants. In this way, the procedure completely bypasses the need for a conscious encounter with feared animals. We demonstrate that our method can lead to reliable reductions in physiological fear responses, as measured by skin conductance as well as amygdala hemodynamic activity. Not only do these results raise the intriguing possibility that naturally occurring fear responses can be “reprogrammed” outside of conscious awareness, importantly, they also create the rare opportunity to rigorously test a psychological intervention of this nature in a double-blind, placebo-controlled fashion. This may pave the way for a new approach combining the appealing rationale and proven efficacy of conventional psychotherapy with the rigor and leverage of clinical neuroscience.

If resources are scarce infants choose ingroup support over fairness.

From Bian et al:

Significance

Recent research suggests that infants possess principles of fairness and ingroup support. We examined whether 1.5- and 2.5-y-olds would prioritize fairness or ingroup support when the two were pitted against each other. Children watched mixed-recipients resource-allocation events in which a puppet distributor faced two potential recipients, an ingroup and an outgroup puppet. Expectations about the distributor’s actions depended on how many allocation items were available. When there were as many items as puppets, children expected fairness to prevail; when there were fewer items than puppets, however, children expected ingroup support to prevail. Thus, beginning early in life, children expect fairness in mixed-recipients scenarios unless there is a shortage of resources, in which case they expect ingroup support to override fairness.

Abstract

Recent research suggests that the foundations of human moral cognition include abstract principles of fairness and ingroup support. We examined which principle 1.5-y-old infants and 2.5-y-old toddlers would prioritize when the two were pitted against each other. In violation-of-expectation tasks, a puppet distributor brought in either two (two-item condition) or three (three-item condition) items and faced two potential recipients, an ingroup and an outgroup puppet. In each condition, the distributor allocated two items in one of three events: She gave one item each to the ingroup and outgroup puppets (equal event), she gave both items to the ingroup puppet (favors-ingroup event), or she gave both items to the outgroup puppet (favors-outgroup event). Children in the two-item condition looked significantly longer at the equal or favors-outgroup event than at the favors-ingroup event, suggesting that when there were only enough items for the group to which the distributor belonged, children detected a violation if she gave any of the items to the outgroup puppet. In the three-item condition, in contrast, children looked significantly longer at the favors-ingroup or favors-outgroup event than at the equal event, suggesting that when there were enough items for all puppets present, children detected a violation if the distributor chose to give two items to one recipient and none to the other, regardless of which recipient was advantaged. Thus, infants and toddlers expected fairness to prevail when there were as many items as puppets, but they expected ingroup support to trump fairness otherwise.

Is loneliness a health epidemic?

Two recent bits of writing on loneliness:

Klinenberg suggests that the 'loneliness epidemic' that has been promoted by numerous recent articles (Britain has appointed its first "minister for loneliness") is an illusion. Loneliness exists as a feature of modern societies, but the best data do not show increase in either loneliness or social isolation between ~1950 and the present.

Pinker, in Figure 18-2 of his new book actually shows data tracking the subjective loneliness of college and high school students over the period 1978-2012, and showing that a small decrease reported loneliness has occurred. His summary comment:

Modern life, then, has not crushed our minds and bodies, turned us into atomized machines suffering from toxic levels of emptiness and isolation, or set us drifting apart without human contact or emotion. How did this hysterical misconception arise? Partly it came out of the social critic’s standard formula for sowing panic: Here’s an anecdote, therefore it’s a trend, therefore it’s a crisis. But partly it came from genuine changes in how people interact. People see each other less in traditional venues like clubs, churches, unions, fraternal organizations, and dinner parties, and more in informal gatherings and via digital media. They confide in fewer distant cousins but in more co-workers. They are less likely to have a large number of friends but also less likely to want a large number of friends.51 But just because social life looks different today from the way it looked in the 1950s, it does not mean that humans, that quintessentially social species, have become any less social.

Predicting the effectiveness of cognitive therapy with functional MRI

Reggente et al. do interesting work showing that MRI measurement of functional connectivity patterns in the default mode and visual networks of obsessive-compulsive disorder (OCD) individuals before entering cognitive therapy predict post treatment OCD severity. Such information could prove useful in choosing between behavioral and drug therapy for a given individual.

Significance

The ability to predict an individual’s potential response to treatment would permit clinicians to more prudently allocate resources that support cognitive behavioral therapy for obsessive–compulsive disorder (OCD), an often stressful and time-consuming treatment. The current study lays important groundwork for an exciting advance toward personalized medicine in psychiatry that up to this point has eluded the field. This study marks a success in using multivariate pattern recognition to identify neurobiological predictors of treatment response. In addition, it advances knowledge of the neurophysiology of OCD and of mechanistic processes involved in the therapeutic response, which could be used to refine existing treatments or to develop novel treatments based on identified potential brain targets.

Abstract

Cognitive behavioral therapy (CBT) is an effective treatment for many with obsessive–compulsive disorder (OCD). However, response varies considerably among individuals. Attaining a means to predict an individual’s potential response would permit clinicians to more prudently allocate resources for this often stressful and time-consuming treatment. We collected resting-state functional magnetic resonance imaging from adults with OCD before and after 4 weeks of intensive daily CBT. We leveraged machine learning with cross-validation to assess the power of functional connectivity (FC) patterns to predict individual posttreatment OCD symptom severity. Pretreatment FC patterns within the default mode network and visual network significantly predicted posttreatment OCD severity, explaining up to 67% of the variance. These networks were stronger predictors than pretreatment clinical scores. Results have clinical implications for developing personalized medicine approaches to identifying individual OCD patients who will maximally benefit from intensive CBT.

Young muscles and immune systems in aging cyclists.

I pass on the technical abstracts of two striking papers referenced by a Gretchen Reynolds article showing that the leg muscles and immune systems of 55-79 year adults who cycle approximately 400 miles/month are similar to those of young adults, suggesting that many features of immune and muscular senescence may be driven by reduced physical activity with age. By most estimates, only about 10 percent of people past the age of 65 work out regularly.

From Pollock et al.:

In this study, results are reported from the analyses of vastus lateralis muscle biopsy samples obtained from a subset (n = 90) of 125 previously phenotyped, highly active male and female cyclists aged 55-79 years in regard to age. We then subsequently attempted to uncover associations between the findings in muscle and in vivo physiological functions. Muscle fibre type and composition (ATPase histochemistry), size (morphometry), capillary density (immunohistochemistry) and mitochondrial protein content (Western blot) in relation to age were determined in the biopsy specimens. Aside from an age-related change in capillary density in males (r = -.299; p = .02), no other parameter measured in the muscle samples showed an association with age. However, in males type I fibres and capillarity (p < .05) were significantly associated with training volume, maximal oxygen uptake, oxygen uptake kinetics and ventilatory threshold. In females, the only association observed was between capillarity and training volume (p < .05). In males, both type II fibre proportion and area (p < .05) were associated with peak power during sprint cycling and with maximal rate of torque development during a maximal voluntary isometric contraction. Mitochondrial protein content was not associated with any cardiorespiratory parameter in either males or females (p > .05). We conclude in this highly active cohort, selected to mitigate most of the effects of inactivity, that there is little evidence of age-related changes in the properties of VL muscle across the age range studied. By contrast, some of these muscle characteristics were correlated with in vivo physiological indices.

and, from Duggal et al.:

It is widely accepted that aging is accompanied by remodelling of the immune system including thymic atrophy and increased frequency of senescent T cells, leading to immune compromise. However, physical activity, which influences immunity but declines dramatically with age, is not considered in this literature. We assessed immune profiles in 125 adults (55-79 years) who had maintained a high level of physical activity (cycling) for much of their adult lives, 75 age-matched older adults and 55 young adults not involved in regular exercise. The frequency of naïve T cells and recent thymic emigrants (RTE) were both higher in cyclists compared with inactive elders, and RTE frequency in cyclists was no different to young adults. Compared with their less active counterparts, the cyclists had significantly higher serum levels of the thymoprotective cytokine IL-7 and lower IL-6, which promotes thymic atrophy. Cyclists also showed additional evidence of reduced immunesenescence, namely lower Th17 polarization and higher B regulatory cell frequency than inactive elders. Physical activity did not protect against all aspects of immunesenescence: CD28^-ve CD57^+ve senescent CD8 T-cell frequency did not differ between cyclists and inactive elders. We conclude that many features of immunesenescence may be driven by reduced physical activity with age.

How is tech dividing us?

Comments by David Autor during an interview by Nancy Scola:

...it's definitely the case that automation is raising the demand for skilled labor. And the work that I've done ... has been about what set of activities are complemented by automation and which set of activities is displaced, pointing out that on the one hand, there were tasks that were creative and analytical, and on the other, tasks that required dexterity and flexibility, which were very difficult to automate. So the middle of the skill distribution, where there are well understood rules and procedures, is actually much more susceptible to automation...That polarization of jobs definitely reduced the set of opportunities for people who don't have a college degree. People who have a high school or lower degree, it used to be they were in manufacturing, in clerical and administrative support. Now, increasingly, they're in cleaning, home health, security, etc.

The greater concern is not about the number of jobs but whether those jobs will pay decent wages and people will have sufficient skills to do them. That's the great challenge. It's never been a better time to be a highly educated worker in the western world. But there hasn't been a worse time to be a high school dropout or high school graduate.

...a lot of what we see—a lot of the political dissatisfaction, as well—comes from the fact that as average wealth and income in the U.S. have risen, it's a very, very geographically concentrated phenomenon. Most of that is basically New York, San Francisco, Los Angeles, San Jose, Houston, Boston, and a couple other places. It's not broadly shared prosperity. A lot of the country is actually kind of downwardly mobile.

You could have imagined a world where we all have Skype and mobile phones and broadband, and no one commutes anywhere, and we all live in our remote hilltop houses overlooking the water, and we'd have no reason to travel. But that doesn't appear to be the case at all.

It appears that remote and in-person communications are complements, not substitutes. Somehow the force of people wanting to clump together has actually, seemingly, if anything gotten stronger. And when we talk about these geographic inequalities, that's what we're seeing.

There are two schools of thought that you hear often. One is, ‘the sky is falling, the robots are coming for our jobs, we're all screwed because we've made ourselves obsolete.’ The other version you also hear a lot is, ‘We've been through things like this in the past, it's all worked out fine, it took care of itself, don't worry.’ And I think both of these are really wrong.

I've indicated I think the first view is wrong. The reason I think the second view is wrong is because I don't think it took care of itself. Countries have very different levels of quality of life, institutional quality, of democracy, of liberty and opportunity, and those are not because they have different markets or different technologies. It's because they've made different institutional arrangements. Look at the example of Norway and Saudi Arabia, two oil-rich countries. Norway is a very happy place. It's economically mobile with high rates of labor force participation, high rates of education, good civil society. And Saudi Arabia is an absolute monarchy that has high standards of living, but it's not a very happy place because they've stifled innovation and individual freedom. Those are two examples of taking the same technology, which is oil wealth, and either squandering it or investing it successfully.

I think the right lesson from history is that this is an opportunity. Things that raise GDP and make us more productive, they definitely create aggregate wealth. The question is, how do we use that wealth well to have a society that's mobile, that's prosperous, that's open? Or do we use it to basically make some people very wealthy and keep everyone else quiet? So, I think we are at an important juncture, and I don't think the U.S. is dealing with it especially well. Our institutions are very much under threat at a time when they're arguably most needed.

Logic in babies.

Halberda does a commentary on work of Cesana-Arlotti et al. showing that one essential form of logical inference, process of elimination, is with the toolkit of 12 month old infants. They used that fact that visual behaviors - such as a shift in one's gaze or a prolonged stare - can be diagnostic of internal thoughts to demonstrate that preverbal infants can formulate a logical structure called a disjunctive syllogism. That is, if A or B is true, and A is false, then B must be true. Presenting infants with scenes where the outcome revealed B to be false evoked looks of surprise:

Cesana-Arlotti et al. asked whether prelinguistic 12- and 19-month-old infants would spontaneously reason using process of elimination. This is a form of inference also known as disjunctive syllogism or modus tollendo ponens—it is any argument of the form: A or B, not A, therefore B. Cesana-Arlotti et al. relied on one of the few behaviors babies voluntarily engage in—looking at whatever they find most interesting. They measured infants' looking at computerized vignettes in which two different objects (A and B) were shown being hidden behind a wall. Infants watched as a cup scooped one of the objects from behind the wall, and then came to rest next to the wall—critically, only the topmost edge of the contained object could be seen peeking out of the cup, such that infants could not tell for sure whether the object was A or B. At this moment, infants could have formed a disjunctive thought—for example, “either the object in the cup is object A or it is object B.” Next, this ambiguity was resolved: The wall dropped to reveal that object A was behind the wall, but the contents of the cup remained hidden. This is the moment of potential elimination, and an opportunity for infants to draw a key inference—“because object A is not in the cup, object B must be in the cup.” Finally, infants' expectations for the cup's contents were tested: Either the expected object (object B) or, surprisingly, another object A emerged from the cup. Infants looked longer at the surprising outcome—an indication that their expectations were violated and a hint that they were seeking further information to resolve the conflict.

Different kinds of smiles elicit different physiological responses

Martin et al. show that our stress chemistry (HPA, or hypothalamic-pituitary-adrenal axis) is augmented or dampened by different kinds of smiles:

When people are being evaluated, their whole body responds. Verbal feedback causes robust activation in the hypothalamic-pituitary-adrenal (HPA) axis. What about nonverbal evaluative feedback? Recent discoveries about the social functions of facial expression have documented three morphologically distinct smiles, which serve the functions of reinforcement, social smoothing, and social challenge. In the present study, participants saw instances of one of three smile types from an evaluator during a modified social stress test. We find evidence in support of the claim that functionally different smiles are sufficient to augment or dampen HPA axis activity. We also find that responses to the meanings of smiles as evaluative feedback are more differentiated in individuals with higher baseline high-frequency heart rate variability (HF-HRV), which is associated with facial expression recognition accuracy. The differentiation is especially evident in response to smiles that are more ambiguous in context. Findings suggest that facial expressions have deep physiological implications and that smiles regulate the social world in a highly nuanced fashion.

YouTube's A.I. finds that radicalization gets more ad revenue.

Tufekci points to yet another pathological social consequence of A.I. algorithms designed to make people stay on a website longer, and thus generate more clicks on advertisements that provide revenue. The YouTube algorithm "seems to have concluded that people are drawn to content that is more extreme than what they started with — or to incendiary content in general." The author found that a YouTube video giving straightforward information on on a Trump rally was followed by autoplay videos "that featured white supremacist rants, Holocaust denials and other disturbing content." The author created another YouTube account to watch videos of Hillary Clinton and Bernie Sander, and was soon auto-directed to "videos of a leftish conspiratorial cast, including arguments about the existence of secret government agencies and allegations that the United States government was behind the attacks of Sept. 11." The same pattern emerges with nonpolitical topics, "Videos about vegetarianism led to videos about veganism. Videos about jogging led to videos about running ultramarathons."

...a former Google engineer named Guillaume Chaslot...worked on the recommender algorithm while at YouTube...The Wall Street Journal conducted an investigation of YouTube content with the help of Mr. Chaslot. It found that YouTube often “fed far-right or far-left videos to users who watched relatively mainstream news sources,” and that such extremist tendencies were evident with a wide variety of material. If you searched for information on the flu vaccine, you were recommended anti-vaccination conspiracy videos.

It is also possible that YouTube’s recommender algorithm has a bias toward inflammatory content. In the run-up to the 2016 election, Mr. Chaslot created a program to keep track of YouTube’s most recommended videos as well as its patterns of recommendations. He discovered that whether you started with a pro-Clinton or pro-Trump video on YouTube, you were many times more likely to end up with a pro-Trump video recommended.

Combine this finding with other research showing that during the 2016 campaign, fake news, which tends toward the outrageous, included much more pro-Trump than pro-Clinton content, and YouTube’s tendency toward the incendiary seems evident.

YouTube has recently come under fire for recommending videos promoting the conspiracy theory that the outspoken survivors of the school shooting in Parkland, Fla., are “crisis actors” masquerading as victims.

What we are witnessing is the computational exploitation of a natural human desire: to look “behind the curtain,” to dig deeper into something that engages us. As we click and click, we are carried along by the exciting sensation of uncovering more secrets and deeper truths. YouTube leads viewers down a rabbit hole of extremism, while Google racks up the ad sales.

This state of affairs is unacceptable but not inevitable. There is no reason to let a company make so much money while potentially helping to radicalize billions of people, reaping the financial benefits while asking society to bear so many of the costs.

The reputation age.

I would like to point to this brief essay by Italian philosopher Gloria Origgi, which offers, after its beginning paragraphs (below), several examples of paradoxes of our information age.

There is an underappreciated paradox of knowledge that plays a pivotal role in our advanced hyper-connected liberal democracies: the greater the amount of information that circulates, the more we rely on so-called reputational devices to evaluate it. What makes this paradoxical is that the vastly increased access to information and knowledge we have today does not empower us or make us more cognitively autonomous. Rather, it renders us more dependent on other people’s judgments and evaluations of the information with which we are faced.

We are experiencing a fundamental paradigm shift in our relationship to knowledge. From the ‘information age’, we are moving towards the ‘reputation age’, in which information will have value only if it is already filtered, evaluated and commented upon by others. Seen in this light, reputation has become a central pillar of collective intelligence today. It is the gatekeeper to knowledge, and the keys to the gate are held by others. The way in which the authority of knowledge is now constructed makes us reliant on what are the inevitably biased judgments of other people, most of whom we do not know.

Think you’re not a competitor? Think again.

From Raghabendra et al.:

We report a series of experimental studies that investigate the influence of a competition on noncompetitors who do not participate in it but are aware of it. Our work is highly relevant across many domains of social life where competitions are prevalent, as it is typical in a competition that the competitors are far outnumbered by these noncompetitors. In our field experiment involving pay-what-you-want entrance at a German zoo (n = 22,886) [with rewards for the top donors], customers who were aware of a competition over entrance payments, but did not participate in it, paid more than customers who were unaware of the competition. Further experiments provide confirmatory and process evidence for this contagion effect, showing that it is driven by heightened social comparison motivation due to mere awareness of the competition. Moreover, we find evidence that the reward level for the competitors could moderate the contagion effect on the noncompetitors. Even if an individual does not participate in a competition, their behavior can still be influenced by it, and this influence can change with the characteristics of the competition in an intriguing way.

Brain coupling during holding hands correlates with pain reduction

From Goldstein et al.:

The mechanisms underlying analgesia related to social touch are not clear. While recent research highlights the role of the empathy of the observer to pain relief in the target, the contribution of social interaction to analgesia is unknown. The current study examines brain-to-brain coupling during pain with interpersonal touch and tests the involvement of interbrain synchrony in pain alleviation. Romantic partners were assigned the roles of target (pain receiver) and observer (pain observer) under pain–no-pain and touch–no-touch conditions concurrent with EEG recording. Brain-to-brain coupling in alpha–mu band (8–12 Hz) was estimated by a three-step multilevel analysis procedure based on running window circular correlation coefficient and post hoc power of the findings was calculated using simulations. Our findings indicate that hand-holding during pain administration increases brain-to-brain coupling in a network that mainly involves the central regions of the pain target and the right hemisphere of the pain observer. Moreover, brain-to-brain coupling in this network was found to correlate with analgesia magnitude and observer’s empathic accuracy. These findings indicate that brain-to-brain coupling may be involved in touch-related analgesia.

Being what we think we are.

Gretchen Reynolds points to an interesting article in Health Psychology by Zahrt and Crum. Following up on an earlier article in which

Crum and her co-author studied 84 female hotel-room attendants, who told the researchers that they felt they completed little or no daily exercise, although their work consisted mostly of physical labor. Crum and her colleague explained to half of them that, in fact, they were meeting or exceeding national recommendations for 30 minutes of daily exercise; a month later, when the researchers checked back, the women said they believed they were getting more exercise than before. They had lost weight and body fat and developed lower blood pressure. But in fact, their daily exertions were the same.

Their new study examined information from 61,141 participants who answered questions about whether they felt they were getting more, less or about the same amount of exercise as most people their age.

They found a strong correlation between people’s dying early and their believing that they were relatively inactive, even if their accelerometer data indicated that they were getting as much exercise as others their age in this group. Risk of early death was up to 71 percent higher than for the group that, correctly or not, felt confident that they exercised more than their peers. This correlation held true when the researchers controlled for chronic diseases, socioeconomic status, smoking and other factors.

Another article, by Paula Span, reports work by Levy et al. extending studies that have shown that people with more positive self-perception of aging actually live longer by an average of 7.5 years. The more recent study shows that implicit interventions can work subliminally to strengthen older people’s positive age stereotypes. That leads, in turn, to stronger physical functioning. The effects were still evident three weeks after the intervention ended. Here is the abstract from Levy et al.:

Negative age stereotypes that older individuals assimilate from their culture predict detrimental outcomes, including worse physical function. We examined, for the first time, whether positive age stereotypes, presented subliminally across multiple sessions in the community, would lead to improved outcomes. Each of 100 older individuals (age = 61–99 years, M = 81) was randomly assigned to an implicit-positive-age-stereotype-intervention group, an explicit-positive-age-stereotype-intervention group, a combined implicit- and explicit-positive-age-stereotype-intervention group, or a control group. Interventions occurred at four 1-week intervals. The implicit intervention strengthened positive age stereotypes, which strengthened positive self-perceptions of aging, which, in turn, improved physical function. The improvement in these outcomes continued for 3 weeks after the last intervention session. Further, negative age stereotypes and negative self-perceptions of aging were weakened. For all outcomes, the implicit intervention’s impact was greater than the explicit intervention’s impact. The physical-function effect of the implicit intervention surpassed a previous study’s 6-month-exercise-intervention’s effect with participants of similar ages. The current study’s findings demonstrate the potential of directing implicit processes toward physical-function enhancement over time.

Rationalizing undesired change as soon as it takes effect.

Lauren does interesting work illustrating how our psychological immune system acts to rationalize and make us feel better about changes we don’t like. This is part of why public revulsion at Trump’s outrageous behaviors is more muted that one might have expected. Here is the abstract:

People will often rationalize the status quo, reconstruing it in an exaggeratedly positive light. They will even rationalize the status quo they anticipate, emphasizing the upsides and minimizing the downsides of sociopolitical realities they expect to take effect. Drawing on recent findings on the psychological triggers of rationalization, I present results from three field studies, one of which was preregistered, testing the hypothesis that an anticipated reality becoming current triggers an observable boost in people’s rationalizations. San Franciscans rationalized a ban on plastic water bottles, Ontarians rationalized a targeted smoking ban, and Americans rationalized the presidency of Donald Trump, more in the days immediately after these realities became current compared with the days immediately before. Additional findings show evidence for a mechanism underlying these behaviors and rule out alternative accounts. These findings carry implications for scholarship on rationalization, for understanding protest behavior, and for policymakers.