Sleep preferentially consolidates negative aspects of human emotional memory

The Nov. 1, 2022 issue of PNAS has a special feature on Sleep, Brain, and Cognition. A large body of research suggests that sleep benefits memory, and I want to point in particular to an article by Denis et al. showing that sleep preferentially consolidates negative aspect of emotional memory. They also found that while research participants demonstrated better memory for positive objects compared to their neutral backgrounds, sleep did not modulate this effect.  

Significance

Recent research has called into question whether sleep improves memory, especially for emotional information. However, many of these studies used a relatively small number of participants and focused only on college student samples, limiting both the power of these findings and their generalizability to the wider population. Here, using the well-established emotional memory trade-off task, we investigated sleep’s impact on memory for emotional components of scenes in a large online sample of adults ranging in age from 18 to 59 y. Despite the limitations inherent in using online samples, this well-powered study provides strong evidence that sleep selectively consolidates negative emotional aspects of memory and that this effect generalizes to participants across young adulthood and middle age.

Abstract

Research suggests that sleep benefits memory. Moreover, it is often claimed that sleep selectively benefits memory for emotionally salient information over neutral information. However, not all scientists are convinced by this relationship [e.g., J. M. Siegel. Curr. Sleep Med. Rep., 7, 15–18 (2021)]. One criticism of the overall sleep and memory literature—like other literature—is that many studies are underpowered and lacking in generalizability [M. J. Cordi, B. Rasch. Curr. Opin. Neurobiol., 67, 1–7 (2021)], thus leaving the evidence mixed and confusing to interpret. Because large replication studies are sorely needed, we recruited over 250 participants spanning various age ranges and backgrounds in an effort to confirm sleep’s preferential emotional memory consolidation benefit using a well-established task. We found that sleep selectively benefits memory for negative emotional objects at the expense of their paired neutral backgrounds, confirming our prior work and clearly demonstrating a role for sleep in emotional memory formation. In a second experiment also using a large sample, we examined whether this effect generalized to positive emotional memory. We found that while participants demonstrated better memory for positive objects compared to their neutral backgrounds, sleep did not modulate this effect. This research provides strong support for a sleep-specific benefit on memory consolidation for specifically negative information and more broadly affirms the benefit of sleep for cognition.

The Neurobiology of long COVID

A number of my friends have reported, having caught break thru Covid even after 3-5 vaccinations, and are having symptoms of long Covid such as brain fog, anosmia, and cognitive impairment. (I am extremely grateful, after five vaccinations, to still be Covid free.) For these friends as well as Mind Blog readers, I want to point to a special issue of Neuron and in particular one open source article "The neurobiology of long Covid," which describes the array of neurological symptoms and their possible causes.

Sadder but Wiser? Maybe Not.

It looks like another universally accepted result of psychological research may be wrong - that depressed people have a more accurate reading of their ability to affect outcomes. Barry points to work by Dev et al. that fails to replicate experiments of Alloy and Abramson done 43 years ago that led to the hypothesis of “depressive realism,” that depressed people having a more realistic view of their conditions because they are free of the optimistic bias of their cheerful peers. The new research was unable to find any association between depressive symptoms and outcome bias. While Barry's review notes debate over whether differences in the design of the older and newer experiments may account for the variance in results, there now is certainly less confidence in the original findings.

Senescent cells targeted by anti-aging therapies may not be all bad

Michael Irving does a brief article in New Atlas that points to work by Reyes et al. showing that some senescent od the sort that accumulate with aging not only secrete inflammatory compounds that can be damaging to tisse around them, but also can play a positive role in repairing tissue damage. This suggests that senolytics research should focus on developing drugs that will target specific subsets of senescent cells that are implicated in disease rather than in regeneration.

Well being increases with diversity of social connections.

From Collins et al.: 

Significance

The link between social connection and well-being is well-documented: Happier people tend to spend more time with others, and people experience greater happiness while socially engaged. But, over and above people’s total amount of social interaction, which set of interactions—with which types of relationship partners (e.g., family members, close friends, acquaintances, strangers), and how many interactions with each type—is most predictive of well-being? Building on research showing the benefits of variety—in activities, experiences, and emotions—for well-being, we document a link between the relational diversity of people’s social portfolios and well-being. Assessing the social interactions and happiness of over 50,000 people reveals that interacting with a more diverse set of relationship types predicts higher well-being.

Abstract

We document a link between the relational diversity of one’s social portfolio—the richness and evenness of relationship types across one’s social interactions—and well-being. Across four distinct samples, respondents from the United States who completed a preregistered survey (n = 578), respondents to the American Time Use Survey (n = 19,197), respondents to the World Health Organization’s Study on Global Aging and Adult Health (n = 10,447), and users of a French mobile application (n = 21,644), specification curve analyses show that the positive relationship between social portfolio diversity and well-being is robust across different metrics of well-being, different categorizations of relationship types, and the inclusion of a wide range of covariates. Over and above people’s total amount of social interaction and the diversity of activities they engage in, the relational diversity of their social portfolio is a unique predictor of well-being, both between individuals and within individuals over time.

Molecular markers of eventual chronic diseases of aging are higher in young adults of lower socioeconomic status.

Sobering work from Shanahan et al.:  

Significance

The analysis of gene expression in peripheral whole blood of US young adults in their late 30s revealed socioeconomic status-based inequalities in the molecular underpinnings of the most common chronic conditions of aging. Associations involved immune, inflammatory, ribosomal, and metabolic pathways, and extra- and intra-cellular signaling. Body mass index was a plausible, sizable mediator of many associations. Results point to new ways of thinking about how social inequalities “get under the skin” and also call for renewed efforts to prevent chronic conditions of aging decades before diagnoses.

Abstract

Many common chronic diseases of aging are negatively associated with socioeconomic status (SES). This study examines whether inequalities can already be observed in the molecular underpinnings of such diseases in the 30s, before many of them become prevalent. Data come from the National Longitudinal Study of Adolescent to Adult Health (Add Health), a large, nationally representative sample of US subjects who were followed for over two decades beginning in adolescence. We now have transcriptomic data (mRNA-seq) from a random subset of 4,543 of these young adults. SES in the household-of-origin and in young adulthood were examined as covariates of a priori-defined mRNA-based disease signatures and of specific gene transcripts identified de novo. An SES composite from young adulthood predicted many disease signatures, as did income and subjective status. Analyses highlighted SES-based inequalities in immune, inflammatory, ribosomal, and metabolic pathways, several of which play central roles in senescence. Many genes are also involved in transcription, translation, and diverse signaling mechanisms. Average causal-mediated effect models suggest that body mass index plays a key role in accounting for these relationships. Overall, the results reveal inequalities in molecular risk factors for chronic diseases often decades before diagnoses and suggest future directions for social signal transduction models that trace how social circumstances regulate the human genome.

Observing the activity of our prosocial brains

Interesting work from Lockwood et al., open source with nice graphics:  

Highlights

• Prosocial behaviors frequently involve exerting effort 

• Human participants completed an effort-based decision-making task during fMRI 

• The anterior cingulate gyrus represented the effort costs of prosocial acts 

• Ventral tegmental area and ventral insula represented value for oneself

Summary

Prosocial behaviors—actions that benefit others—are central to individual and societal well-being. Although the mechanisms underlying the financial and moral costs of prosocial behaviors are increasingly understood, this work has often ignored a key influence on behavior: effort. Many prosocial acts are effortful, and people are averse to the costs of exerting them. However, how the brain encodes effort costs when actions benefit others is unknown. During fMRI, participants completed a decision-making task where they chose in each trial whether to “work” and exert force (30%–70% of maximum grip strength) or “rest” (no effort) for rewards (2–10 credits). Crucially, on separate trials, they made these decisions either to benefit another person or themselves. We used a combination of multivariate representational similarity analysis and model-based univariate analysis to reveal how the costs of prosocial and self-benefiting efforts are processed. Strikingly, we identified a unique neural signature of effort in the anterior cingulate gyrus (ACCg) for prosocial acts, both when choosing to help others and when exerting force to benefit them. This pattern was absent for self-benefiting behaviors. Moreover, stronger, specific representations of prosocial effort in the ACCg were linked to higher levels of empathy and higher subsequent exerted force to benefit others. In contrast, the ventral tegmental area and ventral insula represented value preferentially when choosing for oneself and not for prosocial acts. These findings advance our understanding of the neural mechanisms of prosocial behavior, highlighting the critical role that effort has in the brain circuits that guide helping others.

A lucid exposition on non-dual awareness by James Low

The ‘Waking Up’ app by Sam Harris has posted a series of lectures by James Low that “makes the esoteric teachings of Dzogchen—a non-dual contemplative tradition from Tibet—profoundly accessible.”   I want to pass on to MindBlog readers the following paragraph made up of small clips of text  I have taken from his lecture #4 “The Field of Experience.” Low’s website points to his lectures, writing, and videos of his lectures.

If you want stability, if you want real peace, you already have that in the nature of awareness. But if you look to manifestation, to patterning of yourself, to thinking you could establish a stable personalty, to live a life in which you were happy all the time, or in which you were your own person, that way madness lies. To find our original face, to find the ground of our primordial being, we need to release our fixation on the dialogic movement of subject and object, and allow ourselves to be the space within which the movement of experience is occurring. Awareness means being aware that we are present without being something as such. This is a great mystery. When we look at phenomena the world, things exist as something. A car is not a cow, an apple is not an orange, compare and contrast, category allocation. That’s how our cognition, our conceptual elaboration functions to give a seemingly enduring structure to identifications. But awareness can’t be caught. It’s not a thing. You can’t pin a tail on the donkey, there is no donkey there. The mind is not an object for itself, it is self luminous awareness, but you can’t catch it. You can never know your mind but you can be your mind. We are awareness and that’s a very important distinction.

Generative A.I. - more sociopathic than FaceBook and Twitter?

Have a look at this article on how the sociopathic effects of Facebook and Twitter could be dwarfed by what open source generative A.I. could do. I just played with the DALL-E 2 A.I. system that generates an image when you tell it what you want to see. In response to my request to show "Two abyssinian cats sitting in a window looking out at trees" the following spooky and accurate image appeared.

 

New Perspectives on how our Minds Work

I want to pass on to MindBlog readers this link to a lecture I gave this past Friday (10/21/22) to the Univ. of Texas OLLI (Osher Lifelong Learning Institute) UT FORUM group on Oct. 21, 2022. Here is the brief description of the talk:  

Abstract

Recent research shows that much of what we thought we knew about how our minds work is wrong. Rather than rising from our essential natures, our emotional and social realities are mainly invented by each of us. Modern and ancient perspectives allow us to have some insight into what we have made.

Description

This talk offers a description of how our predictive brains work to generate our perceptions, actions, emotions, concepts, language, and social structures. Our experience that a self or "I" inside our heads is responsible for these behaviors is a useful illusion, but there is in fact no homunculus or discrete place inside our heads where “It all comes together.” Starting before we are born diffuse networks of brain cells begin generating actions and perceiving their consequences to build an internal library of sensing and acting correlations that keep us alive and well, a library that is the source of predictions about what we might expect to happen next in our worlds. Insights from both modern neuroscience research and ancient meditative traditions allow us to partially access and sometimes change this archive that manages our behaviors.

Anxiety - What is it, when is it useful, when is it not?

The title of this post is the discussion topic for the Nov. 6 Austin Rainbow Forum, a monthly discussion group of LGBT seniors that first met in Austin Tx in Jan. 2018. I am using this post to pass on links to some optional background reading:

Martin Seligman and learned helplessness versus helpfulness

Eustress - beneficial stress

Bruce McEwen on good and bad stress

Robert Sapolsky on chronic stress

A deeper look into what our bodies are doing during arousal and calm (click on the arrows at bottom left of presentation frame to expand to full screen)

Facebook has no idea where it keeps our personal data.

A fascinating article from Biddle describing the situation that occured when a court ordered Facebook to turn over information it had collected about a lawsuit’s plaintiffs. Facebook...

...has amassed so much data on so many billions of people and organized it so confusingly that full transparency is impossible on a technical level. In the March 2022 hearing, Zarashaw and Steven Elia, a software engineering manager, described Facebook as a data-processing apparatus so complex that it defies understanding from within. The hearing amounted to two high-ranking engineers at one of the most powerful and resource-flush engineering outfits in history describing their product as an unknowable machine.

The special master at times seemed in disbelief, as when he questioned the engineers over whether any documentation existed for a particular Facebook subsystem. “Someone must have a diagram that says this is where this data is stored,” he said, according to the transcript. Zarashaw responded: “We have a somewhat strange engineering culture compared to most where we don’t generate a lot of artifacts during the engineering process. Effectively the code is its own design document often.” He quickly added, “For what it’s worth, this is terrifying to me when I first joined as well.”

The fundamental problem, according to the engineers in the hearing, is that Facebook’s sprawl has made it impossible to know what it consists of anymore; the company never bothered to cultivate institutional knowledge of how each of these component systems works, what they do, or who’s using them. There is no documentation of what happens to your data once it’s uploaded, because that’s just never been something the company does, the two explained. “It is rare for there to exist artifacts and diagrams on how those systems are then used and what data actually flows through them,”

Musical rhythm training improves short-term memory for faces

From Zanto et al:  

Significance

Musical training can improve numerous cognitive functions associated with musical performance. Yet, there is limited evidence that musical training may benefit nonmusical tasks and it is unclear how the brain may enable such a transfer of benefit. To address this, nonmusicians were randomized to receive 8 wk of either musical rhythm training or word search training. Memory for faces was assessed pre- and post-training while electroencephalography data were recorded to assess changes in brain activity. Results showed that only musical rhythm training improved face memory, which was associated with increased activity in the superior parietal region of the brain when encoding and maintaining faces. Thus, musical rhythm training can improve face memory by facilitating how the brain encodes and maintains memories.

Abstract

Playing a musical instrument engages numerous cognitive abilities, including sensory perception, selective attention, and short-term memory. Mounting evidence indicates that engaging these cognitive functions during musical training will improve performance of these same functions. Yet, it remains unclear the extent these benefits may extend to nonmusical tasks, and what neural mechanisms may enable such transfer. Here, we conducted a preregistered randomized clinical trial where nonmusicians underwent 8 wk of either digital musical rhythm training or word search as control. Only musical rhythm training placed demands on short-term memory, as well as demands on visual perception and selective attention, which are known to facilitate short-term memory. As hypothesized, only the rhythm training group exhibited improved short-term memory on a face recognition task, thereby providing important evidence that musical rhythm training can benefit performance on a nonmusical task. Analysis of electroencephalography data showed that neural activity associated with sensory processing and selective attention were unchanged by training. Rather, rhythm training facilitated neural activity associated with short-term memory encoding, as indexed by an increased P3 of the event-related potential to face stimuli. Moreover, short-term memory maintenance was enhanced, as evidenced by increased two-class (face/scene) decoding accuracy. Activity from both the encoding and maintenance periods each highlight the right superior parietal lobule (SPL) as a source for training-related changes. Together, these results suggest musical rhythm training may improve memory for faces by facilitating activity within the SPL to promote how memories are encoded and maintained, which can be used in a domain-general manner to enhance performance on a nonmusical task.

Sleepless and unhelpful

Simon et al. demonstrate that sleep loss leads to the withdrawal of human helping across individuals, groups, and large-scale societies:

Humans help each other. This fundamental feature of homo sapiens has been one of the most powerful forces sculpting the advent of modern civilizations. But what determines whether humans choose to help one another? Across 3 replicating studies, here, we demonstrate that sleep loss represents one previously unrecognized factor dictating whether humans choose to help each other, observed at 3 different scales (within individuals, across individuals, and across societies). First, at an individual level, 1 night of sleep loss triggers the withdrawal of help from one individual to another. Moreover, fMRI findings revealed that the withdrawal of human helping is associated with deactivation of key nodes within the social cognition brain network that facilitates prosociality. Second, at a group level, ecological night-to-night reductions in sleep across several nights predict corresponding next-day reductions in the choice to help others during day-to-day interactions. Third, at a large-scale national level, we demonstrate that 1 h of lost sleep opportunity, inflicted by the transition to Daylight Saving Time, reduces real-world altruistic helping through the act of donation giving, established through the analysis of over 3 million charitable donations. Therefore, inadequate sleep represents a significant influential force determining whether humans choose to help one another, observable across micro- and macroscopic levels of civilized interaction. The implications of this effect may be non-trivial when considering the essentiality of human helping in the maintenance of cooperative, civil society, combined with the reported decline in sufficient sleep in many first-world nations.

Third-party punishment by preverbal infants

From Kanakogi et al.:

Third-party punishment of antisocial others is unique to humans and seems to be universal across cultures. However, its emergence in ontogeny remains unknown. We developed a participatory cognitive paradigm using gaze-contingency techniques, in which infants can use their gaze to affect agents displayed on a monitor. In this paradigm, fixation on an agent triggers the event of a stone crushing the agent. Throughout five experiments (total N = 120), we show that eight-month-old infants punished antisocial others. Specifically, infants increased their selective looks at the aggressor after watching aggressive interactions. Additionally, three control experiments excluded alternative interpretations of their selective gaze, suggesting that punishment-related decision-making influenced looking behaviour. These findings indicate that a disposition for third-party punishment of antisocial others emerges in early infancy and emphasize the importance of third-party punishment for human cooperation. This behavioural tendency may be a human trait acquired over the course of evolution.

A sleeping touch improves vision.

Interesting work reported by Onuki et al. in the Journal of Neuroscience:   

SIGNIFICANCE STATEMENT

Tactile sensations can bias our visual perception as a form of cross-modal interaction. However, it was reported only in the awake state. Here we show that repetitive directional tactile motion stimulation on the fingertip during slow wave sleep selectively enhanced subsequent visual motion perception. Moreover, the visual improvement was positively associated with sleep slow wave activity. The tactile motion stimulation during slow wave activity increased the activation at the high beta frequency over the occipital electrodes. The visual improvement occurred in agreement with a hand-centered reference frame. These results suggest that our sleeping brain can interpret tactile information based on a hand-centered reference frame, which can cause the sleep-dependent improvement of visual motion detection.

ABSTRACT

Tactile sensations can bias visual perception in the awake state while visual sensitivity is known to be facilitated by sleep. It remains unknown, however, whether the tactile sensation during sleep can bias the visual improvement after sleep. Here, we performed nap experiments in human participants (n = 56, 18 males, 38 females) to demonstrate that repetitive tactile motion stimulation on the fingertip during slow wave sleep selectively enhanced subsequent visual motion detection. The visual improvement was associated with slow wave activity. The high activation at the high beta frequency was found in the occipital electrodes after the tactile motion stimulation during sleep, indicating a visual-tactile cross-modal interaction during sleep. Furthermore, a second experiment (n = 14, 14 females) to examine whether a hand- or head-centered coordination is dominant for the interpretation of tactile motion direction showed that the biasing effect on visual improvement occurs according to the hand-centered coordination. These results suggest that tactile information can be interpreted during sleep, and can induce the selective improvement of post-sleep visual motion detection.

Liberal Democracy versus Christian Democracy

I pass on the opening paragraphs of Thomas Edsall's essay, which offers one of the most succinct summaries I have seen.

Could there soon be an American counterpart to Viktor Orban, the Hungarian prime minister, a right-wing populist who in 2018 declared, “We must demonstrate that there is an alternative to liberal democracy: It is called Christian democracy. And we must show that the liberal elite can be replaced with a Christian democratic elite”?

Liberal democracy, Orban continued,

is liberal, while Christian democracy is, by definition, not liberal: it is, if you like, illiberal. And we can specifically say this in connection with a few important issues — say, three great issues. Liberal democracy is in favor of multiculturalism, while Christian democracy gives priority to Christian culture; this is an illiberal concept. Liberal democracy is pro-immigration, while Christian democracy is anti-immigration; this is again a genuinely illiberal concept. And liberal democracy sides with adaptable family models, while Christian democracy rests on the foundations of the Christian family model; once more, this is an illiberal concept.

Or could there soon be an American counterpart to Giorgia Meloni, another right-wing populist and admirer of Orban, now on course to become the next prime minister of Italy?

Meloni’s platform?

Yes to natural families, no to the L.G.B.T. lobby. Yes to sexual identity, no to gender ideology. Yes to the culture of life, no to the abyss of death. No to the violence of Islam, yes to safer borders. No to mass immigration, yes to work for our people.

I highly recommend reading the rest of Edsall's article on the signals pointing to the vulnerability of the liberal state.

Cognitive and Evolutionary Foundations of Puritanical Morality

MindBlog receives articles for commentary from the Cambridge University Journal of Behavioral and Brain Sciences. I will pass on the following abstract of an article by Fitouchi et. al. Motivated readers can email me to request a copy.

Why do many societies moralize apparently harmless pleasures, such as lust, gluttony, alcohol, drugs, and even music and dance? Why do they erect temperance, asceticism, sobriety, modesty, and piety as cardinal moral virtues? According to existing theories, this puritanical morality cannot be reduced to concerns for harm and fairness: it must emerge from cognitive systems that did not evolve for cooperation (e.g., disgust-based "Purity" concerns). Here, we argue that, despite appearances, puritanical morality is no exception to the cooperative function of moral cognition. It emerges in response to a key feature of cooperation, namely that cooperation is (ultimately) a long-term strategy, requiring (proximately) the self-control of appetites for immediate gratification. Puritanical moralizations condemn behaviors which, although inherently harmless, are perceived as indirectly facilitating uncooperative behaviors, by impairing the self-control required to refrain from cheating. Drinking, drugs, immodest clothing, and unruly music and dance, are condemned as stimulating short-term impulses, thus facilitating uncooperative behaviors (e.g., violence, adultery, free-riding). Overindulgence in harmless bodily pleasures (e.g., masturbation, gluttony) is perceived as making people slave to their urges, thus altering abilities to resist future antisocial temptations. Daily self-discipline, ascetic temperance, and pious ritual observance are perceived as cultivating the self-control required to honor prosocial obligations. We review psychological, historical, and ethnographic evidence supporting this account. We use this theory to explain the fall of puritanism in WEIRD societies, and discuss the cultural evolution of puritanical norms. Explaining puritanical norms does not require adding mechanisms unrelated to cooperation in our models of the moral mind.

Triggers for mother love

A fascinating open source article from Margaret Livingstone carrying forward the famous experiments by Harry Harlow:  

Significance

Harry Harlow found that infant monkeys form strong and lasting attachments to inanimate surrogates, but only if the surrogate is soft; here I report that postpartum monkey mothers can also form strong and lasting attachments to soft inanimate objects. Thus, mother/infant and infant/mother bonds may both be triggered by soft touch.

Abstract

Previous studies showed that baby monkeys separated from their mothers develop strong and lasting attachments to inanimate surrogate mothers, but only if the surrogate has a soft texture; soft texture is more important for the infant’s attachment than is the provision of milk. Here I report that postpartum female monkeys also form strong and persistent attachments to inanimate surrogate infants, that the template for triggering maternal attachment is also tactile, and that even a brief period of attachment formation can dominate visual and auditory cues indicating a more appropriate target.

Trigger warnings and ‘safety-ism’ don’t work.

Mark Manson does an engaging "Mindf*ck Monday Newsletter from Sept. 7" that I recommend you have a look at. It cites a meta-analysis by Brigland et al. that shows that trigger warning don't work, in some cases they may make things worse. Their abstract:

Trigger warnings, content warnings, or content notes are alerts about upcoming content that may contain themes related to past negative experiences. Advocates claim that warnings help people to emotionally prepare for or completely avoid distressing material. Critics argue that warnings both contribute to a culture of avoidance at odds with evidence-based treatment practices and instill fear about upcoming content. Recently, a body of psychological research has begun to investigate these claims empirically. We present the results of a meta-analysis of all empirical studies on the effects of these warnings. Overall, we found that warnings have no effect on affective responses to negative material nor on educational outcomes (i.e., comprehension). However, warnings reliably increase anticipatory affect. Findings on avoidance were mixed, suggesting either that warnings have no effect on engagement with material, or that they increase engagement with negative material under specific circumstances. Limitations and implications for policy and therapeutic practice are discussed.

Manson also discusses the dying fad of "safety-ism" noted by Jonathan Haidt and Greg Lukianoff in their book "The Coddling of the American Mind," and makes the point that...

The human mind is antifragile—that is, it gains from discomfort and strain. That means to grow stronger, the human mind needs to regularly be confronted with difficult and upsetting experiences to develop stability and serenity for itself.