Screams and the communication soundscape

A fascinating piece from Amal noting that human screams occupy a privileged niche in the communication soundscape.

Highlights

•We provide the first evidence of a special acoustic regime (“roughness”) for screams 

•Roughness is used in both natural and artificial alarm signals 

•Roughness confers a behavioral advantage to react rapidly and efficiently 

•Acoustic roughness selectively activates amygdala, involved in danger processing

Summary

Screaming is arguably one of the most relevant communication signals for survival in humans. Despite their practical relevance and their theoretical significance as innate and virtually universal vocalizations, what makes screams a unique signal and how they are processed is not known. Here, we use acoustic analyses, psychophysical experiments, and neuroimaging to isolate those features that confer to screams their alarming nature, and we track their processing in the human brain. Using the modulation power spectrum, a recently developed, neurally informed characterization of sounds, we demonstrate that human screams cluster within restricted portion of the acoustic space (between ∼30 and 150 Hz modulation rates) that corresponds to a well-known perceptual attribute, roughness. In contrast to the received view that roughness is irrelevant for communication, our data reveal that the acoustic space occupied by the rough vocal regime is segregated from other signals, including speech, a pre-requisite to avoid false alarms in normal vocal communication. We show that roughness is present in natural alarm signals as well as in artificial alarms and that the presence of roughness in sounds boosts their detection in various tasks. Using fMRI, we show that acoustic roughness engages subcortical structures critical to rapidly appraise danger. Altogether, these data demonstrate that screams occupy a privileged acoustic niche that, being separated from other communication signals, ensures their biological and ultimately social efficiency.

Ohmygawd - a social app that aims for fleeting authenticity?

I prodded my troglodyte brain to actually read this article about yet another social networking app, Beme, and came away fascinated. More constant and fleeting interacting than I want or could handle, but a  clever trick with an iPhone. You just hold the front of the phone against your chest, and the phone's proximity detector functions as a record button to film the scene you are facing. You can view the Bemes of friends you are following, as they can view yours. If you like, you can send a real time selfie to react to what your friend is doing.... after viewing is done, the exchange is erased. Talk about fleeting glances.  WIRED magazine thinks that this flight from the curated self to authenticity may be judged to be too boring by many users.

 

How experiencing nature influences our brains.

Bratman et al., in their PNAS article with the title "Nature experience reduces rumination and subgenual prefrontal cortex activation," suggest an explanation for why nature experience, in contrast to urban experience, enhances our sense of well-being:

Urbanization has many benefits, but it also is associated with increased levels of mental illness, including depression. (More than 50% of people now live in urban areas. By 2050 this proportion will be 70%.) It has been suggested that decreased nature experience may help to explain the link between urbanization and mental illness. This suggestion is supported by a growing body of correlational and experimental evidence, which raises a further question: what mechanism(s) link decreased nature experience to the development of mental illness? One such mechanism might be the impact of nature exposure on rumination, a maladaptive pattern of self-referential thought that is associated with heightened risk for depression and other mental illnesses. We show in healthy participants that a brief nature experience, a 90-min walk in a natural setting, decreases both self-reported rumination and neural activity in the subgenual prefrontal cortex (sgPFC), whereas a 90-min walk in an urban setting has no such effects on self-reported rumination or neural activity. In other studies, the sgPFC has been associated with a self-focused behavioral withdrawal linked to rumination in both depressed and healthy individuals. This study reveals a pathway by which nature experience may improve mental well-being and suggests that accessible natural areas within urban contexts may be a critical resource for mental health in our rapidly urbanizing world.

From the body of the paper:

On arrival at our laboratory, each participant completed a self-report measure of rumination (RRQ) and underwent our scanning procedure. We then randomly assigned each participant to a 90-min walk in either a natural environment (19 participants) or urban environment (19 participants). The nature walk took place near Stanford University, in a greenspace comprising grassland with scattered oak trees and shrubs. The urban walk took place on the busiest thoroughfare in nearby Palo Alto (El Camino Real), a street with three to four lanes in each direction and a steady stream of traffic (Fig. S1). After the walk, each participant returned to the laboratory and provided a second, follow-up self-report of levels of rumination (RRQ) before undergoing a second resting-state ASL scan. Transportation to and from the walk was via a car ride of 15-min duration (for both walks). Participants were given a smartphone and told to take 10 photographs during their walk (Fig. S2). These photographs were used to verify that participants went on the walk. We also tracked the phone itself during the walk, as further verification that the correct route was taken by each participant.

The impact of nature experience on self-reported rumination and blood perfusion to the sgPFC. (A) Change in self-reported rumination (postwalk minus prewalk) for participants randomly assigned to take a 90-min walk either in a natural setting or in an urban setting. (B) A time-by-environment interaction in blood perfusion was evident in the sgPFC. F map of significant interactions at a threshold of P less than 0.05, FWE corrected for multiple comparisons. (C) Change in blood perfusion (postwalk minus prewalk) for participants randomly assigned to take a 90-min walk either in a natural setting or in an urban setting. Error bars represent SE within subjects: *P less than 0.05, ***P less than 0.001.

Happy or anxious?

I want to point to two interesting recent pieces:
Luhrmann notes that the Western, and particularly American, definition of anxiety or depression is very different from that of some other cultures. And, that

...personal thoughts and feelings are the central drivers of human action — not roles, not values, not personal sensation, not God. In the United States, the enormous psychotherapeutic and self-help industry teaches us that we must pay scrupulous attention to inner experience. To succeed and be happy, we are taught, we need to know what we feel.

She comments on the movie "Inside Out," mentioned in previous posts:

It’s a charming movie. It is also distinctly American. It is based on a particular model of the mind that we take for granted, but that is in fact as culturally idiosyncratic as the way we dress. I’m not suggesting that the basic science of emotion depicted in the movie is wrong. Emotions do seem to be crucial in organizing human thinking. I’m suggesting that there is something deeply cultural about the way this mind is imagined, and that it has consequences for the way we experience thoughts and feelings.

Our high anxiety, whatever the challenges we face, is probably one of the consequences.

Cederstrom notes an insidious and political side to the emphasis on interiority, knowing how we feel, as a condition for happiness. After referencing Darrin M. McMahon's recent book "Happiness: A History," he writes:

When happiness is recast as an individual choice, attitude becomes everything and circumstances are made irrelevant. Martin Seligman, the founder of positive psychology, has worked hard to spread this message, referring to studies that suggest that victims of car crashes are, on the whole, neither less nor more unhappy than lottery winners.

Even if we find such insights interesting or inspiring, they do not form a particularly helpful basis when we seek to make happiness the goal of politics. If we may all be equally happy, irrespective of our circumstances, then that would equip politicians like Mr. Bush with a convenient excuse to stop looking at structural issues like class, social and economic inequality or poverty.

When happiness has become championed and talked about incessantly, as it is today, the best we can hope for is that it raises other universal issues — like equality, justice, truth and ethics, which we desperately need to discuss. The worst that can happen — and this is unfortunately already underway — is that happiness becomes a Trojan horse used to normalize inequality and oppression. Poor people may then be sent to happiness courses to improve their attitudes, or assigned personal life coaches, as Paul Ryan once proposed in his bizarre anti-poverty plan.

Be wary. When politicians suggest that happiness be made the ultimate aim for society we should remember that they are probably not talking about happiness at all. They are talking about ideology: their own political agendas in disguise.

Sense8 - Sympathetic Sci-Fi

I started watching the NetFlix original Sci-Fi drama series "Sense8" two weeks ago, and was completely hooked, watching one episode every day until I had finished all twelve. It is about 8 people scattered over the world who can occupy each other's minds and bodies by a telepathic "limbic resonance." I recommend the recent New Yorker article by Josh Rothman on this series.

The defining scene of “Sense8,” the new sci-fi drama on Netflix, comes about halfway through the first season. It starts in San Francisco, where Nomi, a “hacktivist” and transgender lesbian, is making out with her girlfriend, Amanita. At the same time, in Mexico City, Lito, a smoldering actor, is lifting weights with his boyfriend, Hernando. In Berlin, Wolfgang, a safecracker, is relaxing, naked, in a hot tub. And in Chicago, Will, a police officer, is working out at the gym. The premise of “Sense8” is that Nomi, Lito, Wolfgang, and Will—along with four other “sensates” in Nairobi, Seoul, Mumbai, and Reykjavik—are telepathically linked. They are able to feel each other’s emotions, appear in each other’s minds, and even control each other’s bodies. In this instance, because they’re all feeling sexy, the sensates find themselves having an impromptu telepathic orgy. They’re a little freaked out until they realize that they can all enjoy Wolfgang’s hot tub simultaneously.

In sci-fi speak, “Sense8” is about transhumanism—the idea that in the future, as a species, we might become more than we are right now. Julian Huxley, the brother of Aldous, coined the term in a 1927 book called “Religion Without Revelation,” in which he wrote that transhumanism was “man remaining man, but transcending himself, by realizing new possibilities of and for his human nature.”

Rothman gives a fascinating summary of different categories of Sci-Fi. I recommended that you read the article. I can't resist a few more clips:

If you read a lot of science fiction in one go, you notice that it has two weaknesses. The first is the future, which tends to be complicated, depressing, and fatiguing to read about; the second is the aesthetic of futurism, which is grim and predictable. Everything is big, scary, and metallic (or else small, gross, and biotechnological). The implicit message of futurism is that human progress is inseparable from suffering; often, the only kind of beauty is terrible beauty. Futurism is what gives sci-fi its frisson.

“Sense8,” though, is joyful, in part because it shows us transhumanism without futurism. It’s not a superhero show, in which a random individual is elevated into something better; it hints, science-fictionally, at a fundamental change in human nature generally. At the same time, there’s no technological explanation—and, therefore, no futurist cost—for that change. (In one episode, it’s suggested that, in the distant evolutionary past, all human beings were once telepathic, but no one seems to care very much about this hand-wavey idea.) On some level, the sensates’ telepathic empathy is a metaphor for the Internet, which seems, in some ways, to be making us more open to others’ experiences (especially queer experiences). The show also evokes the joys of creative collaboration: people who watch the Wakowskis work together often say that they have “two bodies, one brain.” Really, though, the point of “Sense8” is to revel in the broadening of empathy—to fantasize about how in-tune with each other we could be. In its own, low-key way, therefore, “Sense8” is a critique of sci-fi. It asks whether, in tying our dreams about human transformation to fantasies of technological development, we might be making an error. The show suggests another path to transcendence: each other.

How did kindness come to be our forbidden pleasure?

This post is a tertiary product: a review of a review of a book. In this case I want to note Maria Popova’s piece on the book by Adam Phillips and Barbara Taylor, “On Kindness,” and pass on a few clips:

…only in recent times — in large part thanks to Emerson — did the ideal of independence and self-reliance become the benchmark of spiritual success. The need for belonging has become an intolerable manifestation of vulnerability…Perhaps because open-heartedness is impossible without vulnerability — an open heart is an aperture through which the world can enter us, but also one through which exploitive and cruel forces can penetrate the softest core of who we are without obstruction — the original meaning of and longing for kindness has been calcified by our impulse for armoring and self-protection.

….despite our resistance to kindness, some deeper, dormant part of us still registers it, still cringes upon encountering its absence. This paradoxical relationship with kindness, perhaps more so than anything else, explains the “outrage culture” of the internet: “We usually know what the kind thing to do is — and kindness when it is done to us, and register its absence when it is not… We are never as kind as we want to be, but nothing outrages us more than people being unkind to us. There is nothing we feel more consistently deprived of than kindness; the unkindness of others has become our contemporary complaint. Kindness consistently preoccupies us, and yet most of us are unable to live a life guided by it.”

“The pleasure of kindness is that it connects us with others; but the terror of kindness is that it makes us too immediately aware of our own and other people’s vulnerabilities (vulnerabilities that we are prone to call failings when we are at our most frightened). Vulnerability — particularly the vulnerability we call desire — is our shared biological inheritance. Kindness, in other words, opens us up to the world (and worlds) of other people in ways that we both long for and dread.”

For all of its pervasive undertones of and platforms for outrage, contemporary culture — and the digital universe that is part of it — offers fertile new soil in which to grow the natural inclinations that give rise to the pleasure of communion and kindness. Taylor and Phillips capture this beautifully:

“By involving us with strangers (even with “foreigners” thousands of miles away), as well as with intimates, [kindness] is potentially far more promiscuous than sexuality. But … the child needs the adult — and his wider society — to help him keep faith with his kindness, that is, to help him discover and enjoy the pleasures of caring for others… People have long known this, and long forgotten it. The history of kindness … tells the story of this knowing, and forgetting, and reknowing, as central to Western ideas about the good life.”

Four books from Edge.org's summer reading list.

I pass on links to four books that I'm very tempted to buy and read:

Mindware: Tools for Smart Thinking - Richard E. Nisbett

A Beautiful Question: Finding Nature's Deep Design - Frank Wilczek

Machines of Loving Grace: The Quest for Common Ground Between Humans and Robots - John Markoff

Cool: How the Brain's Hidden Quest for Cool Drives Our Economy and Shapes Our World - Steven Quartz and Anette Asp

Participants in the senior olympics have fitness age 25 years younger than their chronological age.

I have previously mentioned the fitness age calculator developed by reserarchers at the Norwegian University of Science and Technology in Trondheim. Gretchen Reynolds now does a piece on a study that has looked at the results obtained when more than 4,200 participants in this year's senior olympics in Minneapolis-St. Paul used the online calculator to determine their physiological age (which predicts longevity and general vitality with aging). The striking result was the athletes, whose average chronological age was 68, had an average fitness age of 43, a remarkable 25 years less. Here is the link to the calculator, if you are curious to try it on yourself. (I couldn't resist doing it again for myself. I'm 73, and the calculator is kind enough to tell me I have a fitness age of 53.)

Cleaning up the queue - interesting ideas.

As I scan the table of contents for various journals, mining for material that might become a MindBlog post, I accumulate a long list of links that I think are fascinating, but that I never get around to developing into a post. Here is a random list of a few of those:

How to better learn things. Review of Benedict's Carey's book on how to most effectively learn new things.

Ways in which women are better decision makers. In tense or anxious situations, men are more likely to make risky decisions. The tendency to take more risks when under pressure is stronger in men who experience a larger spike in cortisol. In women a slight increase in cortisol seems actually to improve decision-making performance.

Related to the above, Endogenous cortisol predicts decreased loss aversion in young men.

Internet research project draws conservative ire. A 4-year-old academic study of how information spreads on Twitter has become the target of withering attacks from conservative bloggers and politicians. The Truthy project, by researchers at Indiana University (IU), Bloomington, is part of a growing body of work on how online memes—messages about ideas, issues, and events—can shape phenomena ranging from protest movements to outbreaks of disease. The National Science Foundation is a major funder of the project, which is one element in a broader initiative to understand complex, nonlinear feedback systems. But critics, who cite the project as an unwise use of taxpayer dollars, say Truthy is really an attempt by the U.S. government to monitor and restrict free speech. IU scientists say that is a gross distortion of what they have been doing.

Purpose in life and use of preventative health care services. Less than 50% of people over the age of 65 are up-to-date with core preventive services. Identifying modifiable factors linked with preventive services are important targets for research and practice. Purpose in life, recently the focus of multiple intervention studies, has been linked with better health (mental and physical) as well as improved health behaviors. However, its association with health care use has been understudied. We found that higher purpose was linked with greater use of several preventive health care services and also fewer nights spent hospitalized. These results may facilitate the development of new strategies to increase use of preventive health care services and improve health, thereby offsetting the burden of rising health care costs in our aging society.

Genetic risk factors for bipolar disorder and schizophrenia predict creativity.

As a follow up to my June 30 post on creativity and neurosis, I wanted to point to the following account by Power et al. (Numerous epidemiological studies have demonstrated overlap between psychiatric disorders and creativity, suggesting that creative genius and insanity are characterized by similar unleashing of thoughts and emotions.)

We tested whether polygenic risk scores for schizophrenia and bipolar disorder would predict creativity. Higher scores were associated with artistic society membership or creative profession in both Icelandic (P = 5.2 × 10⁻⁶ and 3.8 × 10⁻⁶ for schizophrenia and bipolar disorder scores, respectively) and replication cohorts (P = 0.0021 and 0.00086). This could not be accounted for by increased relatedness between creative individuals and those with psychoses, indicating that creativity and psychosis share genetic roots.

From the review by Keller and Visscher:

They used a large discovery sample of 86,292 adults from Iceland and four replication samples totaling over 27,000 adults from Sweden and the Netherlands. All had genome-wide SNP genotyping and their professions were known. None of them knowingly suffered from a psychiatric illness. About 1% of them were artists, including actors, dancers, musicians and writers. The authors piggy-backed on recent large genome-wide association studies (GWASs) conducted on SCZ (Schizophrenia) and BD (bipolar disorder) patients and controls, and used the estimated effect on risk of SCZ and BD from thousands of SNP variants that were associated with either SCZ or BD. They then used the observed genotypes in the healthy people from Iceland, Sweden and the Netherlands and predicted a genetic risk score—the sum of associated risk alleles weighted by their estimated effect sizes. Power et al. found that people at higher genetic risk for SCZ or BD had a higher probability of being employed as an artist or belonging to an artists' union.

Evolving ourselves

I pass on a few clips from Xue’s review of “Evolving Ourselves: How Unnatural Selection and Nonrandom Mutation Are Changing Life on Earth” by  J. Enriquez and S. Gullans:

Welcome to the post-genomic age. The idea of the human genome is obsolete…It’s fashionable now to speak of multiple genomes in a single individual, generated by mutations that occur as the body’s cells grow and divide. And genomes aren’t enough: everything has an “-ome” these days. The epigenome, proteome, microbiome, metabolome, connectome, interactome—each vies to be the next new scientific thing to set the public imagination on fire.  

If genes seem to lose their luster, there is no shortage of biological paradigms looking to take their place. The authors describe the epigenome—chemical modifications to DNA that affect when genes are expressed—as each person’s “second genome,” one subject to heritable change due to environmental effects. As it happens, “Second Genome” is also the name of a company that aims to develop therapeutic interventions for the microbiome, which has been increasingly linked to physical health as well as moods and mental disease. “My microbiome made me do it,” one T-shirt proclaims.

It’s no surprise that scientists and the media alike embrace these totalizing languages. They have a seductive simplicity. Genomes first or second are reified into biology itself; scientific progress morphs into promises of technologically designed utopia. “Forever Young, Beautiful, and Fearless?” asks one chapter. “The Robot-Computer-Human Interface,” posits another. It is enough, I hope, to give one pause. Genetic (epigenetic, microbial) engineering could be used for disastrous ends, with or without intent. At the grand-historical scale of the authors’ imaginings, technologies alone cleave a Gordian knot, leaving convoluted personal, political, and societal consequences in their wake.

We may submit to these totalizing scientific vocabularies to pursue fantasies of total biological control, but the bargain is Faustian. When scientific concepts become all that is worth knowing, humanity shrinks to fit what can be known. When all aspects of the human experience are fully and scientifically understood—when DNA becomes the language of personality, and hormones, microbes, and electric pulses the substance of emotion—when genes, memories, and thoughts can be generated and manipulated at will—then, will mankind have ascended at last?   

The embodied cognition of your love life.

MindBlog has done a number of posts on how physical changes in our bodies can influence social cognition (Holding a warm versus an iced cup of coffee makes you more friendly). In yet another example of embodied cognition, Forest et al. note an interesting relationship between physical instability and perceived social relationship stability.

What influences how people feel about and behave toward their romantic partners? Extending beyond features of the partners, relationship experiences, and social context, the current research examines whether benign, relationship-irrelevant factors—such as one’s somatic experiences—can influence relationship perceptions and interpersonal behavior. Drawing on the embodiment literature, we propose that experiencing physical instability can undermine perceptions of relationship stability. Participants who experienced physical instability by sitting at a wobbly workstation rather than a stable workstation (Study 1), standing on one foot rather than two (Study 2), or sitting on an inflatable seat cushion rather than a rigid one (Study 3) perceived their romantic relationships to be less likely to last. Results were consistent with risk-regulation theory: Perceptions of relational instability were associated with reporting lower relationship quality (Studies 1–3) and expressing less affection toward the partner (Studies 2 and 3). These findings indicate that benign physical experiences can influence perceptions of relationship stability, exerting downstream effects on consequential relationship processes.

Kinda Neat! - a Soft Jumping Robot

Using a multi-material 3D printer for manufacturing allowed Wyss Institute researchers (Bartlett et al.) to fabricate the jumping robot in one uninterrupted job, seamlessly transitioning from rigid core components to a soft exterior in a single print session. It's first ever robot to be 3D printed with layers of material gradients, making it extremely durable and giving the jumping robot a long lifespan of use, and could lead to a new class of functionally-graded soft robots.

 

Why don't the poor rise up?

Thomas Edsall offers interesting comments on the seeming intractability of rising inequality in our society, and I pass on a few clips, continuing the MindBlog topic thread that has been contrasting the brains and behaviors of advantaged and disadvantaged segments of our society (cf. here).

Why are today’s working poor so quiescent?...First, although incomes have declined, the cost of many goods – televisions, computers, air-conditioners, household appliances, cellphones – has fallen, leaving the bottom quintile less deprived than simple income figures might reflect. Second, people nowadays marry and have children later in life than in the past, postponing some financial demands to better earning years. Third, some economists contend that commonly used inflation measures result in excessively high estimates of the real-world cost of goods for consumers, thus making living conditions less dire than they might otherwise be.

But there is another reason that there has not been broad public insurrection...Society has drastically changed since the high-water mark of the 1930s and 1960s when collective movements captured the public imagination. Now, there is an inexorable pressure on individuals to, in effect, fly solo. There is very little social support for class-based protest – what used to be called solidarity...Collective social action...has been supplanted by a different kind of revolt...the top priorities of the specific movements associated with individualization – “the feminist movement, lesbian-gay-bisexual-transgender movements, the black power movement, the disability rights movement, and, most recently, the fat-acceptance movement” – do not lend themselves to broad economic demands on behalf of the less well off.

Edsall offers summaries worth reading, of the arguments in several recent books on the individualization of society over the past 50 years.

Political ideology, self control, and belief in free will.

MindBlog has a thread of posts noting psychological studies on those who endorse traditional values and the status quo (conservatives) versus those who endorse egalitarian ideals and progressive change (liberals). Clarkson et al. add a further interesting instalment to such studies, using the usual gaggle of ~150 college undergraduates the first two of their three studies, and ~150 subjects chosen by Amazon's Mechanical Turk for the third.:

Significance

Surprisingly little is known about the self-control consequences of individuals’ political ideologies, given the centrality of political ideology to people’s self-identity and the vitality of self-control to human functioning. This research addresses this unexplored gap by offering insight into the processes (freewill beliefs) and factors (the value of freewill for effective self-control) that lead both conservatives and liberals to demonstrate greater self-control. In doing so, these findings provide a platform by which to broaden our understanding of the underlying mechanisms impacting self-control as well as an alternative perspective for interpreting previously documented differences between conservatives and liberals (e.g., intelligence, academic success).

Abstract

Evidence from three studies reveals a critical difference in self-control as a function of political ideology. Specifically, greater endorsement of political conservatism (versus liberalism) was associated with greater attention regulation and task persistence. Moreover, this relationship is shown to stem from varying beliefs in freewill; specifically, the association between political ideology and self-control is mediated by differences in the extent to which belief in freewill is endorsed, is independent of task performance or motivation, and is reversed when freewill is perceived to impede (rather than enhance) self-control. Collectively, these findings offer insight into the self-control consequences of political ideology by detailing conditions under which conservatives and liberals are better suited to engage in self-control and outlining the role of freewill beliefs in determining these conditions.

Caffeine as an antidote to depression caused by stress.

Kaster et al. do work that suggests adenosine A2A receptor (A2AR) antagonists might be therapeutic agents for relieving stress induced depression.:

Epidemiological studies show that individuals exposed to repeated stress, a major trigger of depression, increase their caffeine intake, which correlates inversely with the incidence of depression. However, the mechanism underlying this protective effect is unknown. We used an animal model of chronic unpredictable stress (CUS) to show that caffeine prevents the maladaptive changes caused by CUS in a manner mimicked by the selective blockade of adenosine A2A receptors (A2AR). CUS enhanced A2AR in synapses, and the selective elimination of neuronal A2AR abrogated CUS modifications. Moreover, A2AR blockade also afforded a therapeutic benefit, paving the way to consider A2AR blockers as a strategy to manage the negative impact of chronic stress on mood and memory.

Groups are better lie detectors than individuals.

From Klein and Epley:

Significance

Detecting lies is difficult. Accuracy rates in experiments are only slightly greater than chance, even among trained professionals. Costly programs aimed at training individual lie detectors have mostly been ineffective. Here we test a different strategy: asking individuals to detect lies as a group. We find a consistent group advantage for detecting small “white” lies as well as intentional high-stakes lies. This group advantage does not come through the statistical aggregation of individual opinions (a “wisdom-of-crowds” effect), but instead through the process of group discussion. Groups were not simply maximizing the small amounts of accuracy contained among individual members but were instead creating a unique type of accuracy altogether.

Abstract

Groups of individuals can sometimes make more accurate judgments than the average individual could make alone. We tested whether this group advantage extends to lie detection, an exceptionally challenging judgment with accuracy rates rarely exceeding chance. In four experiments, we find that groups are consistently more accurate than individuals in distinguishing truths from lies, an effect that comes primarily from an increased ability to correctly identify when a person is lying. These experiments demonstrate that the group advantage in lie detection comes through the process of group discussion, and is not a product of aggregating individual opinions (a “wisdom-of-crowds” effect) or of altering response biases (such as reducing the “truth bias”). Interventions to improve lie detection typically focus on improving individual judgment, a costly and generally ineffective endeavor. Our findings suggest a cheap and simple synergistic approach of enabling group discussion before rendering a judgment.

The science of 'Inside-Out"'

Sure enough - after last Monday's post pointing to Anthony Lane's review of 'Inside-Out' and noting how accurately the movie's depiction of goings-on inside an 11-year old girl's head corresponded to current neuroscience accounts of how our brains work - today's New York Times has an op-ed piece by psychologists Dacher Keltner and Paul Ekman, who in fact were scientific advisors to writer and director Pete Docter. They grumble a bit that Docter decided that the story could only handle five or six internal actors (Anger, Disgust, Fear, Sadness and Joy)rather than the more full array currently being studied by researchers like Keltner and others. (I've debated taking myself to the theater to watch the whole movie surrounded by a bunch of 8-13 year olds, and discover, short of doing that, that simply entering Inside Out in the YouTube search window gets you to brief video clips from different parts of the movie depicting its core animations of memory, the control room, etc.) A few clips from the Keltner and Ekman Op-Ed:

...the movie’s portrayal of sadness successfully dramatizes two central insights from the science of emotion. First, emotions organize — rather than disrupt — rational thinking. Traditionally, in the history of Western thought, the prevailing view has been that emotions are enemies of rationality and disruptive of cooperative social relations...But the truth is that emotions guide our perceptions of the world, our memories of the past and even our moral judgments of right and wrong, most typically in ways that enable effective responses to the current situation...Second, emotions organize — rather than disrupt — our social lives. Studies have found, for example, that emotions structure (not just color) such disparate social interactions as attachment between parents and children, sibling conflicts, flirtations between young courters and negotiations between rivals...Other studies find that it is anger (more so than a sense of political identity) that moves social collectives to protest and remedy injustice. Research that one of us has conducted has found that expressions of embarrassment trigger others to forgive when we’ve acted in ways that momentarily violate social norms.

The Higher Life - A mindfulness guru for the tech set.

A brief post to point to an engaging article in The New Yorker by Lizzie Widdicombe that describes the efforts of Andy Puddicombe and others to bring meditation and mindfulness techniques to digital burnouts, expanding the definition of success beyond money and power to include well-being, wonder, wisdom, giving...etc.

The smell of happiness.

Here's an interesting bit. de Groot et al. obtained armpit sweat from 12 young Caucasian heterosexual men in three consecutive sessions (with fear-inducing, happiness-inducing, or neutral film clips), separated by a week's interval. 36 female Caucasian undergraduates served as "receivers" of the odor stimuli. Exposure to sweat from happy senders elicited a happier facial expression than did sweat from fearful or neutral senders; further, sweat from happy senders elicited a more global processing style relative to sweat from fearful senders. Here is their abstract:

It is well known that feelings of happiness transfer between individuals through mimicry induced by vision and hearing. The evidence is inconclusive, however, as to whether happiness can be communicated through the sense of smell via chemosignals. As chemosignals are a known medium for transferring negative emotions from a sender to a receiver, we examined whether chemosignals are also involved in the transmission of positive emotions. Positive emotions are important for overall well-being and yet relatively neglected in research on chemosignaling, arguably because of the stronger survival benefits linked with negative emotions. We observed that exposure to body odor collected from senders of chemosignals in a happy state induced a facial expression and perceptual-processing style indicative of happiness in the receivers of those signals. Our findings suggest that not only negative affect but also a positive state (happiness) can be transferred by means of odors.

Cat videos are good for your health.

Why are there more than 2 million cat videos on YouTube with an average of 12,000 views per clip? Myrick surveyed ~ 7,000 internet users to find that in general people felt less anxious, annoyed or sad after watching the clips, with an emotional payoff that was stronger than feeling of guilt over procrastinating. And, it certainly is cheaper than paying a shrink! Here is the abstract, which gives you an idea of the waffling nature of the text:

Anecdotes abound about the frequent use of the Internet to view cat-related media. Yet, research has yet to seriously address this popular culture phenomenon rooted largely in social media platforms. It is possible that viewing of online cat media improves mood, but this activity may also foster negative outcomes linked to using the Internet for procrastination. The present survey of Internet users (N = 6795) explored the correlates of viewing “Internet cats,” motivations for consuming this media, and its potential effects on users. It also tested a conceptual model predicting enjoyment as a function of the relationships between procrastination, guilt, and happiness. Results reveal significant relationships between viewing and personality types and demonstrate conceptual nuances related to the emotional benefits of watching Internet cats.

I can't resist throwing in a cat video as a bonus:

 

Anti-ageing pill pushed as a bona fide drug.

Amazing. Now we are going to start treating normal aging as a disease? Maybe not as crazy as it sounds. Some clips from a review by Hayden:

Current treatments for diseases related to ageing “just exchange one disease for another”, says physician Nir Barzilai of the Albert Einstein College of Medicine in New York. That is because people treated for one age-related disease often go on to die from another relatively soon thereafter. “What we want to show is that if we delay ageing, that’s the best way to delay disease.”

Barzilai and other researchers plan to test that notion in a clinical trial called Targeting Aging with Metformin, or TAME. They will give the drug metformin to thousands of people who already have one or two of three conditions — cancer, heart disease or cognitive impairment — or are at risk of them. People with type 2 diabetes cannot be enrolled because metformin is already used to treat that disease. The participants will then be monitored to see whether the medication forestalls the illnesses they do not already have, as well as diabetes and death.

On 24 June, researchers will try to convince FDA officials that if the trial succeeds, they will have proved that a drug can delay ageing. That would set a precedent that ageing is a disorder that can be treated with medicines, and perhaps spur progress and funding for ageing research.

The TAME test is for metformin, which suppresses glucose production by the liver and increases sensitivity to insulin. The drug has been used for more than 60 years and is safe and prolongs healthy life and lifespan in worms and in some mouse strains. Data also suggest that it could delay heart disease, cancer, cognitive decline and death in people with diabetes. Plans call for the trial to enrol 3,000 people aged 70–80 years at roughly 15 centres around the United States. The trial will take 5–7 years and cost US$50 million, Barzilai estimates, although it does not yet have funding.

The power of positivity.

Ramirez et al. make the fascinating observation that depressive-like stress responses in mice can be acutely suppressed through artificial reactivation of a small population of neurons that had previously been activated by a positive experience - these cells apparently being the physical substrate, or engram, of the positive memory. This suggests a fundamental explanation for why eliciting the recall of pleasant memories can sometimes be an effective psychotherapeutic technique for relieving stress, lack of motivation, or anhedonia in humans.

Stress is considered a potent environmental risk factor for many behavioural abnormalities, including anxiety and mood disorders. Animal models can exhibit limited but quantifiable behavioural impairments resulting from chronic stress, including deficits in motivation, abnormal responses to behavioural challenges, and anhedonia. The hippocampus is thought to negatively regulate the stress response and to mediate various cognitive and mnemonic aspects of stress-induced impairments, although the neuronal underpinnings sufficient to support behavioural improvements are largely unknown. Here we acutely rescue stress-induced depression-related behaviours in mice by optogenetically reactivating dentate gyrus cells that were previously active during a positive experience. A brain-wide histological investigation, coupled with pharmacological and projection-specific optogenetic blockade experiments, identified glutamatergic activity in the hippocampus–amygdala–nucleus-accumbens pathway as a candidate circuit supporting the acute rescue. Finally, chronically reactivating hippocampal cells associated with a positive memory resulted in the rescue of stress-induced behavioural impairments and neurogenesis at time points beyond the light stimulation. Together, our data suggest that activating positive memories artificially is sufficient to suppress depression-like behaviours and point to dentate gyrus engram cells as potential therapeutic nodes for intervening with maladaptive behavioural states.

Inside Out

I can't resist passing on a few selected clips from Anthony Lane's review of the new Pixar Movie, "Inside Out." Pixar writer and director Pete Docter, in describing the actor's inside a child's head, has produced an an engaging depiction of of many of the ideas I try to get across (much more obtusely and ponderously) in my MindStuff: Guide for the curious user written ten years ago.

The new Pixar film, “Inside Out,” is about the life of Riley. She is an only child...who, aged eleven, moves with her parents ... from Minnesota to San Francisco. Not much happens...The bulk of the movie takes place out of sight, within the confines of Riley’s mind, where primary feelings affect her every move. There are five in all: Joy (Amy Poehler), who is butter-yellow and fuzzy at the edges; Anger (Lewis Black), who looks like SpongeBob soaked in blood; Fear (Bill Hader), a writhing dweeb with a bow tie; Disgust (Mindy Kaling), who has frosted green hair and lashes; and Sadness (Phyllis Smith), a bespectacled blob of blue. Now and then, they contend for supremacy, but mostly they join forces and react to the world beyond. They behold it through Riley’s eyes, from a spiffy control center, like Kirk, Spock, and the gang on the bridge of the Enterprise...Dreams are produced in—where else?—a dream factory, with soundstages and camera crews. It closes down when she wakes. Experiences are delivered to the control room as if they were bowling balls, colored according to their mood; some are stored away, others dropped into a pit of forgetfulness, where they darken and crumble like spent coals, and a few are enthroned as core memories. And that, we are told, is how a personality is made.

So brisk is the defining of all this...that we barely pause to consider the assumptions behind it. Pixar...has no time for old-school habits, like lodging the emotions in the heart...They are located squarely in the brain, presumably displacing Reason, whom we never meet, but whom I picture as French, bald, and wearing an English suit. ... Neurologists and therapists will examine the movie and pronounce themselves largely satisfied. ... I sensed..., that I was following the transcription, by very clever adults, of their own theorizing—literate, frantic, and endlessly chewed over—on the subject of human development, rather than the story of a growing girl.

...the biggest laughs, without exception, come when we exit Riley’s head and take a quick vacation to the crania—and the mania—of others. During an argument at dinner, for instance, her father’s emotions are miles away; all of them are watching a hockey game. And, as the closing credits approach, Docter, realizing that he has a pack of wild gags that have been kept leashed for too long, releases the lot in a flurry. We peek inside the mind of a dog, a cat, a prepubescent boy (“Girl! Girl!” the alarms sing out), and, best of all, the cool chick with eyeshadow at Riley’s school, voiced by Rashida Jones. ...You start to wonder what a grownup sequel to “Inside Out” would look like, with a host of new feelings barging into central command and wrenching the controls away from Joy. Would Lust be spoken by Rupert Everett, or would it sound more like Chico Marx, working his way through a chorus line? How about Love of Money, or black-browed Mortal Terror? There are places, I guess, where even Pixar cannot go.

Neuroanatomical correlates of the income-achievement gap.

The difference in academic achievement between students from higher- and lower-income backgrounds is substantial and growing. A group of collaborators from M.I.T., Harvard, and Columbia has examined the neuroanatomical correlates of the income-achievement gap by comparing the structure of the cerebral cortex (which supports perception, language, and thought) in public-school students who do (lower income) and do not (higher income) receive free or reduced-price lunch, and by relating this neuroanatomy to performance on standardized tests of academic skills. For further discussion of effects of poverty on young brains see the article by Ostrander in The New Yorker.

In the United States, the difference in academic achievement between higher- and lower-income students (i.e., the income-achievement gap) is substantial and growing. In the research reported here, we investigated neuroanatomical correlates of this gap in adolescents (N = 58) in whom academic achievement was measured by statewide standardized testing. Cortical gray-matter volume was significantly greater in students from higher-income backgrounds (n = 35) than in students from lower-income backgrounds (n = 23), but cortical white-matter volume and total cortical surface area did not differ significantly between groups. Cortical thickness in all lobes of the brain was greater in students from higher-income than lower-income backgrounds. Greater cortical thickness, particularly in temporal and occipital lobes, was associated with better test performance. These results represent the first evidence that cortical thickness in higher- and lower-income students differs across broad swaths of the brain and that cortical thickness is related to scores on academic-achievement tests.

Cortical-thickness differences between income groups. The brain images in (a) show regions where cortical thickness was significantly greater in the higher-income (HI) group than in the lower-income (LI) group.

Facebook internal research shows its algorithms enhance political polarization.

From the commentary by Lazer:

Bakshy et al. examine... whether Facebook's curation of news feeds prevents the intersection of conflicting points of view. That is, does a “filter bubble” emerge from this algorithmic curation process, so that individuals only see posts that they agree with? Such an algorithmic sorting has the potential to be unhealthy for our democracy, fostering polarization and undermining the construction of a vision of the common good...Their answer, after parsing the Facebook pages of ∼10 million U.S. individuals with self-declared ideologies, is that the curation does ideologically filter what we see.

It is laudable that Facebook supported this research and has invested in the public good of general scientific knowledge. Indeed, the information age hegemons should proactively support research on the ethical implications of the systems that they build. Facebook deserves great credit for building a talented research group and for conducting this research in a public way.

Here is the Bakshy et al. abstract:

Exposure to news, opinion, and civic information increasingly occurs through social media. How do these online networks influence exposure to perspectives that cut across ideological lines? Using deidentified data, we examined how 10.1 million U.S. Facebook users interact with socially shared news. We directly measured ideological homophily in friend networks and examined the extent to which heterogeneous friends could potentially expose individuals to cross-cutting content. We then quantified the extent to which individuals encounter comparatively more or less diverse content while interacting via Facebook’s algorithmically ranked News Feed and further studied users’ choices to click through to ideologically discordant content. Compared with algorithmic ranking, individuals’ choices played a stronger role in limiting exposure to cross-cutting content.

Acetaminophen - over the counter relief from both pain and emotions...

I've sometimes wondered why I feel a bit flat (anhedonic) after taking acetaminophen (Tylenol). Durso et al. show that it blunts sensitivity to both negative and positive stimuli.

Acetaminophen, an effective and popular over-the-counter pain reliever (e.g., the active ingredient in Tylenol), has recently been shown to blunt individuals’ reactivity to a range of negative stimuli in addition to physical pain. Because accumulating research has shown that individuals’ reactivity to both negative and positive stimuli can be influenced by a single factor (an idea known as differential susceptibility), we conducted two experiments testing whether acetaminophen blunted individuals’ evaluations of and emotional reactions to both negative and positive images from the International Affective Picture System. Participants who took acetaminophen evaluated unpleasant stimuli less negatively and pleasant stimuli less positively, compared with participants who took a placebo. Participants in the acetaminophen condition also rated both negative and positive stimuli as less emotionally arousing than did participants in the placebo condition (Studies 1 and 2), whereas nonevaluative ratings (extent of color saturation in each image; Study 2) were not affected by drug condition. These findings suggest that acetaminophen has a general blunting effect on individuals’ evaluative and emotional processing, irrespective of negative or positive valence.

How is creativity helped by being just a little bit crazy?

Park et al. examine individuals with schizotypal personality disorder, which is characterized by need for social isolation, anxiety in social situations, odd behavior and thinking, and often unconventional beliefs, but does not engage the false beliefs, unclear or confused thinking, and auditory hallucinations characteristic of schizophrenia. They suggest that the greater levels of creative behavior found in such individuals correlates with deactivation of specific cortical areas, in agreement with 'less is more' models for creativity.

Empirical studies indicate a link between creativity and schizotypal personality traits, where individuals who score highly on schizotypy measures also display greater levels of creative behaviour. However, the exact nature of this relationship is not yet clear, with only a few studies examining this association using neuroimaging methods. In the present study, the neural substrates of creative thinking were assessed with a drawing task paradigm in healthy individuals using fMRI. These regions were then statistically correlated with the participants’ level of schizotypy as measured by the Oxford–Liverpool Inventory of Feelings and Experiences (O-LIFE), which is a questionnaire consisting of four dimensions. Neural activations associated with the creativity task were observed in bilateral inferior temporal gyri, left insula, left parietal lobule, right angular gyrus, as well as regions in the prefrontal cortex. This widespread pattern of activation suggests that creative thinking utilises multiple neurocognitive networks, with creative production being the result of collaboration between these regions. Furthermore, the correlational analyses found the Unusual Experiences factor of the O-LIFE to be the most common dimension associated with these areas, followed by the Impulsive Nonconformity dimension. These correlations were negative, indicating that individuals who scored the highest in these factors displayed the least amount of activation when performing the creative task. This is in line with the idea that ‘less is more’ for creativity, where the deactivation of specific cortical areas may facilitate creativity. Thus, these findings contribute to the evidence of a common neural basis between creativity and schizotypy.

A new class of anti-aging drugs that selectively kill senescent cells.

From  Brian Ray in the Editor's Choice section of the June 5 issue of Science, another approach to life-extension drugs (and, to possibly curb your enthusiasm about the desirability of such anti-aging efforts, also have a look at "What Happens When We All Live to 100?" in The Atlantic Magazine). :

As organisms age, they accumulate cells that can no longer proliferate. Such cells— termed “senescent”—persist and appear to promote aging by producing and secreting a variety of proteins. Zhu et al. tested whether drugs that inhibit cellular signaling pathways that make senescent cells resistant to stress and cell death could deplete senescent cells in mice. A combination of two drugs that inhibit such pathways selectively killed senescent cells in vitro, improved heart and vascular function in aging mice, and improved symptoms in a mouse model of accelerated aging. Although pinpointing the relevant targets of these drugs is difficult, the studies indicate that selectively targeting senescent cells with small molecules may be feasible.

The Zhu et al. technical abstract:

The healthspan of mice is enhanced by killing senescent cells using a transgenic suicide gene. Achieving the same using small molecules would have a tremendous impact on quality of life and the burden of age-related chronic diseases. Here, we describe the rationale for identification and validation of a new class of drugs termed senolytics, which selectively kill senescent cells. By transcript analysis, we discovered increased expression of pro-survival networks in senescent cells, consistent with their established resistance to apoptosis. Using siRNA to silence expression of key nodes of this network, including ephrins (EFNB1 or 3), PI3Kδ, p21, BCL-xL, or plasminogen-activated inhibitor-2, killed senescent cells, but not proliferating or quiescent, differentiated cells. Drugs targeting these same factors selectively killed senescent cells. Dasatinib eliminated senescent human fat cell progenitors, while quercetin was more effective against senescent human endothelial cells and mouse BM-MSCs. The combination of dasatinib and quercetin was effective in eliminating senescent MEFs. In vivo, this combination reduced senescent cell burden in chronologically aged, radiation-exposed, and progeroid Ercc1^−/Δ mice. In old mice, cardiac function and carotid vascular reactivity were improved 5 days after a single dose. Following irradiation of one limb in mice, a single dose led to improved exercise capacity for at least 7 months following drug treatment. Periodic drug administration extended healthspan in Ercc1^−/Δ mice, delaying age-related symptoms and pathology, osteoporosis, and loss of intervertebral disk proteoglycans. These results demonstrate the feasibility of selectively ablating senescent cells and the efficacy of senolytics for alleviating symptoms of frailty and extending healthspan.

Ocytocin reverses amphetamine-induced deficits in social bonding.

As a followup to yesterday's post on a positive effects of amphetamine on the cognition of aging adults, I thought it would be interesting to point out a dark side of amphetamine by noting the paper by Young et al. showing reversal of amphetamine-induced social impairments by oxytocin treatment. (In addicts who fail to develop or maintain intimate relationships amphetamine appears to hijack the brain's social reward circuitry. Clinical trials in humans are indicating a clear potential for oxytocin as a treatment for addiction.) They use the prairie vole male pair bonding model.

Drug addiction has devastating consequences on social behaviors and can lead to the impairment of social bonding. Accumulating evidence indicates that alterations in oxytocin (OT) and dopamine (DA) neurotransmission within brain reward circuitry may be involved. We investigated this possibility, as well as the therapeutic potential of OT for drug-induced social deficits, using the prairie vole (Microtus ochrogaster)—a socially monogamous rodent that forms enduring pair bonds between adult mates. We demonstrate that repeated exposure to the commonly abused psychostimulant amphetamine (AMPH) inhibits the formation of partner preferences (an index of pair bonding) in female prairie voles. AMPH exposure also altered OT and DA neurotransmission in regions that mediate partner preference formation: it decreased OT and DA D2 receptor immunoreactivity in the medial prefrontal cortex (mPFC) and nucleus accumbens (NAcc), respectively, and increased NAcc DA levels. Administration of OT directly into the mPFC of AMPH-exposed voles restored partner preferences, and altered NAcc DA levels, and this effect was dependent on OT receptor activation. Together, these data suggest that repeated AMPH exposure impairs pair bonding through an OT-mediated mechanism, and that OT and DA systems within brain reward circuitry may interact to mediate the complex relationship between drug abuse and social bonding. Further, these results provide empirical support for the idea that the central OT system may represent an important target for the treatment of social deficits in addiction.

A bit of amphetamine turns older brains into younger brains.

Fascinating. Garrett et al. show that raising dopamine levels with amphetamine (sold as the prescription drug Adderall, for ADHD), increases the brain wave variability that enhances working memory, so that seniors perform as well as younger people on the n-back working memory test. (Common prescription doses of 5-30 mg act as a cognitive enhancer.

Higher doses can be aphrodisiac, euphoriant, addictive, and have many bad side effects.) I pass on both their statement of significance and abstract. Also, a figure that tempts me to try to get an adderall prescription and do a self experiment.

Significance

Younger, better performing adults typically show greater brain signal variability than older, poorer performers, but the mechanisms underlying this observation remain elusive. We attempt to restore deficient functional-MRI–based blood oxygen level-dependent (BOLD) signal variability (SDBOLD) levels in older adults by boosting dopamine via d-amphetamine (AMPH). Notably, older adults met or exceeded young adult SDBOLD levels under AMPH. AMPH-driven changes in SDSDBOLD also predicted AMPH-driven changes in reaction time speed and variability on a working memory task, but depended greatly on age and drug administration order. These findings (i) suggest that dopamine may account for adult age differences in brain signal variability and (ii) highlight the importance of considering practice effects and state dependencies when evaluating the neurochemical basis of age- and cognition-related brain dynamics. 

Abstract

Better-performing younger adults typically express greater brain signal variability relative to older, poorer performers. Mechanisms for age and performance-graded differences in brain dynamics have, however, not yet been uncovered. Given the age-related decline of the dopamine (DA) system in normal cognitive aging, DA neuromodulation is one plausible mechanism. Hence, agents that boost systemic DA [such as d-amphetamine (AMPH)] may help to restore deficient signal variability levels. Furthermore, despite the standard practice of counterbalancing drug session order (AMPH first vs. placebo first), it remains understudied how AMPH may interact with practice effects, possibly influencing whether DA up-regulation is functional. We examined the effects of AMPH on functional-MRI–based blood oxygen level-dependent (BOLD) signal variability (SDBOLD) in younger and older adults during a working memory task (letter n-back). Older adults expressed lower brain signal variability at placebo, but met or exceeded young adult SDBOLD levels in the presence of AMPH. Drug session order greatly moderated change–change relations between AMPH-driven SDBOLD and reaction time means (RTmean) and SDs (RTSD). Older adults who received AMPH in the first session tended to improve in RTmean and RTSD when SDBOLD was boosted on AMPH, whereas younger and older adults who received AMPH in the second session showed either a performance improvement when SDBOLD decreased (for RTmean) or no effect at all (for RTSD). The present findings support the hypothesis that age differences in brain signal variability reflect aging-induced changes in dopaminergic neuromodulation. The observed interactions among AMPH, age, and session order highlight the state- and practice-dependent neurochemical basis of human brain dynamics.

Figure. Increased BOLD variability and improved cognitive performance under AMPH. Multivariate partial least-squares model of relation between SDBOLD, Age Group, AMPH, and Task Condition. Higher brain scores reflect higher BOLD signal variability. Error bars represent bootstrapped 95% confidence intervals (1,000× with replacement). Brain images are plotted in neurological orientation (left is Left). AMPH, amphetamine; BSR, bootstrap ratio.

Brain areas that place us in the past, present and future.

Here is an interesting bit of work from Kurczek et al. showing that thinking about the past and future requires activation of the hippocampus in the medial temporal lobes,and referring oneself to that thinking requires medial prefrontal cortex.

Highlights

•We examined the role of the MTL and mPFC in self-projection and self-referential processing.

•MTL patients were impaired in self-projection but not self-referential processing.

•mPFC patients were impaired in self-referential processing but not self-projection.

•MTL and mPFC make differential contributions to the neural network supporting self-projection and self-referential processing.

Abstract

Converging evidence points to a neural network that supports a range of abilities including remembering the past, thinking about the future, and introspecting about oneself and others. Neuroimaging studies find hippocampal activation during event construction tasks, and patients with hippocampal amnesia are impaired in their ability to (re)construct events of the past and the future. Neuroimaging studies of constructed experiences similarly implicate the medial prefrontal cortex (mPFC), but it remains unknown whether the mPFC is critical for such processes. The current study compares performance of five patients with bilateral mPFC damage, six patients with bilateral hippocampal damage, and demographically matched comparison participants on an event construction task. Participants were given a neutral cue word and asked to (re)construct events across four time conditions: real past, imagined past, imagined present, and future. These event narratives were analyzed for the number of internal and external details to quantify the extent of episodic (re)experiencing. Given the literature on the involvement of the mPFC in self-referential processing, we also analyzed the event narratives for self-references. The patients with mPFC damage did not differ from healthy comparison participants in their ability to construct highly detailed episodic events across time periods but displayed disruptions in their incorporation of the self. Patients with hippocampal damage showed the opposite pattern; they were impaired in their ability to construct highly detailed episodic events across time periods but not in their incorporation of the self. The results suggest differential contributions of hippocampus and medial prefrontal cortex to the distributed neural network for various forms of self-projection.

Constructing rich false memories of committing crime.

Yet another study, from Shaw and Porter, demonstrating how flawed our memory systems can be. This sort of experiment explains in part the continuing parade of individuals, imprisoned on the basis of false witness memories reported after suggestive interviews with zealous prosecutors, who are being released on the basis of evidence suppressed or ignored in their trial.

Memory researchers long have speculated that certain tactics may lead people to recall crimes that never occurred, and thus could potentially lead to false confessions. This is the first study to provide evidence suggesting that full episodic false memories of committing crime can be generated in a controlled experimental setting. With suggestive memory-retrieval techniques, participants were induced to generate criminal and noncriminal emotional false memories, and we compared these false memories with true memories of emotional events. After three interviews, 70% of participants were classified as having false memories of committing a crime (theft, assault, or assault with a weapon) that led to police contact in early adolescence and volunteered a detailed false account. These reported false memories of crime were similar to false memories of noncriminal events and to true memory accounts, having the same kinds of complex descriptive and multisensory components. It appears that in the context of a highly suggestive interview, people can quite readily generate rich false memories of committing crime.

Brain markers of psychopathy.

Philippi et al. analyze 142 adult male prison inmates, and offer a detailed analysis showing that psychopathy can be correlated with altered connectivity in the default mode, frontoparietal, and cingulo-opercular networks. There are no correlations with connectivity in auditory or visual networks. The authors note that "the large and diverse inmate sample affords us a unique opportunity to examine the neural correlates of the two primary “factors” and the four “facets,” or dimensions, of psychopathy. Factor 1 corresponds to the interpersonal/affective traits of psychopathy (e.g., callousness, egocentrism), whereas Factor 2 corresponds to the lifestyle/antisocial features (e.g., impulsivity, irresponsibility). Factor 1 can be further subdivided into Facet 1 (interpersonal traits) and Facet 2 (affective traits), whereas Factor 2 can be further subdivided into Facet 3 (lifestyle traits) and Facet 4 (antisocial traits)." Here is their rather dense and condensed abstract:

Psychopathy is a personality disorder characterized by callous antisocial behavior and criminal recidivism. Here we examine whether psychopathy is associated with alterations in functional connectivity in three large-scale cortical networks. Using fMRI in 142 adult male prison inmates, we computed resting-state functional connectivity using seeds from the default mode network, frontoparietal network, and cingulo-opercular network. To determine the specificity of our findings to these cortical networks, we also calculated functional connectivity using seeds from two comparison primary sensory networks: visual and auditory networks. Regression analyses related network connectivity to overall psychopathy scores and to subscores for the “factors” and “facets” of psychopathy: Factor 1, interpersonal/affective traits; Factor 2, lifestyle/antisocial traits; Facet 1, interpersonal; Facet 2, affective; Facet 3, lifestyle; Facet 4, antisocial. Overall psychopathy severity was associated with reduced functional connectivity between lateral parietal cortex and dorsal anterior cingulate cortex. The two factor scores exhibited contrasting relationships with functional connectivity: Factor 1 scores were associated with reduced functional connectivity in the three cortical networks, whereas Factor 2 scores were associated with heightened connectivity in the same networks. This dissociation was evident particularly in the functional connectivity between anterior insula and dorsal anterior cingulate cortex. The facet scores also demonstrated distinct patterns of connectivity. We found no associations between psychopathy scores and functional connectivity within visual or auditory networks. These findings provide novel evidence on the neural correlates of psychopathy and suggest that connectivity between cortical association hubs, such as the dorsal anterior cingulate cortex, may be a neurobiological marker of the disorder.

Sign language as a window on universals in linguistic representation of events.

From Strickland et al., I've learned a new word - telicity:

According to a theoretical tradition dating back to Aristotle, verbs can be classified into two broad categories. Telic verbs (e.g., “decide,” “sell,” “die”) encode a logical endpoint, whereas atelic verbs (e.g., “think,” “negotiate,” “run”) do not, and the denoted event could therefore logically continue indefinitely. Here we show that sign languages encode telicity in a seemingly universal way and moreover that even nonsigners lacking any prior experience with sign language understand these encodings. In experiments 1–5, nonsigning English speakers accurately distinguished between telic (e.g., “decide”) and atelic (e.g., “think”) signs from (the historically unrelated) Italian Sign Language, Sign Language of the Netherlands, and Turkish Sign Language. These results were not due to participants' inferring that the sign merely imitated the action in question. In experiment 6, we used pseudosigns to show that the presence of a salient visual boundary at the end of a gesture was sufficient to elicit telic interpretations, whereas repeated movement without salient boundaries elicited atelic interpretations. Experiments 7–10 confirmed that these visual cues were used by all of the sign languages studied here. Together, these results suggest that signers and nonsigners share universally accessible notions of telicity as well as universally accessible “mapping biases” between telicity and visual form.

Oxytocin makes formidable men more likeable.

An interesting tidbit from Chen et al.:

Physical size and strength are associated with dominance and threat. The current study tested (i) whether men’s evaluations of male strangers would be negatively influenced by cues indicating physical formidability, and (ii) whether these evaluations would be influenced by oxytocin, a neuropeptide that mediates social behavior and reduces social anxiety. In a placebo-controlled double-blind design, we administered either oxytocin (24 I.U.) or placebo intranasally to 100 healthy males and assessed their responses to an image of either a physically formidable (strong) or physically non-formidable (weak) male peer. Whereas participants receiving placebo expressed dislike and avoidance of the strong male relative to the weak male, oxytocin selectively improved social evaluation of the strong male. These results provide first evidence that oxytocin regulates social evaluation of peers based on body features indicating strength and formidability. We discuss the possibility that oxytocin may promote the expansion of social networks by increasing openness toward potentially threatening individuals.

Serotonin deficiency correlates with stress vulnerability.

From Sachs et al., a statement of significance, followed by a more detailed abstract:

Significance

The biological factors that determine whether an individual develops mental illness, such as depression or posttraumatic stress disorder, or responds adequately to pharmacotherapy remain almost completely unknown. Using genetically modified mice, we demonstrate that low levels of brain serotonin lead to increased vulnerability to psychosocial stress and prevent the antidepressant-like effects of fluoxetine following stress exposure. Our data also show that inhibiting the lateral habenula can reverse stress-induced behavioral avoidance in serotonin-deficient animals, which fail to respond to fluoxetine. Our results provide additional insight into the serotonin deficiency hypothesis of depression and highlight the potential of targeting the lateral habenula to treat depression and anxiety disorders in patients who fail to respond to selective serotonin reuptake inhibitors.

Abstract

Brain serotonin (5-HT) deficiency and exposure to psychosocial stress have both been implicated in the etiology of depression and anxiety disorders, but whether 5-HT deficiency influences susceptibility to depression- and anxiety-like phenotypes induced by psychosocial stress has not been formally established. Most clinically effective antidepressants increase the extracellular levels of 5-HT, and thus it has been hypothesized that antidepressant responses result from the reversal of endogenous 5-HT deficiency, but this hypothesis remains highly controversial. Here we evaluated the impact of brain 5-HT deficiency on stress susceptibility and antidepressant-like responses using tryptophan hydroxylase 2 knockin (Tph2KI) mice, which display 60–80% reductions in brain 5-HT. Our results demonstrate that 5-HT deficiency leads to increased susceptibility to social defeat stress (SDS), a model of psychosocial stress, and prevents the fluoxetine (FLX)-induced reversal of SDS-induced social avoidance, suggesting that 5-HT deficiency may impair antidepressant responses. In light of recent clinical and preclinical studies highlighting the potential of inhibiting the lateral habenula (LHb) to achieve antidepressant and antidepressant-like responses, we also examined whether LHb inhibition could achieve antidepressant-like responses in FLX-insensitive Tph2KI mice subjected to SDS. Our data reveal that using designer receptors exclusively activated by designer drugs (DREADDs) to inhibit LHb activity leads to reduced SDS-induced social avoidance behavior in both WT and Tph2KI mice. This observation provides additional preclinical evidence that inhibiting the LHb might represent a promising alternative therapeutic approach under conditions in which selective 5-HT reuptake inhibitors are ineffective.

The urge to instruct.

I thought I would pass on this humorous piece by Peter Funt on his review of YouTube videos on how to break in a new baseball glove. After reviewing videos on using microwave ovens, jacuzzis, mallets, oil, heat, hot water:

After nearly two hours of viewing, I’ve learned that: (a) it appears no certification is necessary to teach on YouTube; (b) although baseball is the national pastime, no one knows how to break in a glove; and (c) if you accidentally lock a new mitt in an old car, you might be able to use a tennis ball to break in.

This sets me to mulling on what motivates the making of such videos, and indeed, what motives me to pass on or describe articles about mind, brain, and behavior that I have very little real critical insight into. Just as with a kid showing off a new toy, the 'gee whiz' or 'this is neat' moment that comes from encountering a new idea or bit of work is enhanced by sharing it with others.

The "Good Life"

The previous post noting recent work by Dacher Keltner and collaborators prompted me to have another look at the website of "The Greater Good Science Center" at the University of California Berkeley that Keltner and others have established. It has recently developed another website, Greater Good in Action, that offers engaging brief exercises in practices shown by research to enhance and build all sorts of good stuff: connection, empathy, kindness, compassion, forgiveness, gratitude, happiness, optimism, resilience to stress, awe, etc. Just clicking through, and spending maybe 5-10 minutes, on a few of the exercises leaves me with a mushy warm glow of contentment, which persists for varying periods of time until my usual default curmudgeonly self reappears. You might enjoy trying some.

Why do we experience awe?

Awe, like reverence, is a pro-social emotion that subordinates individual self interest to a larger whole. Dacher Keltner and Paul Piff, in their NYTimes piece publicizing of their more academic publication (marketing is a necessity these days) describe five different studies, each providing experimental evidence that awe helps bind us to others, motivating us to be more generous and helpful to strangers, to act in collaborative ways that enable strong groups and cohesive communities. The positive effect of awe on prosociality are partly explained by feelings of a smaller self.

...even brief experiences of awe, such as being amid beautiful tall trees, lead people to feel less narcissistic and entitled and more attuned to the common humanity people share with one another. In the great balancing act of our social lives, between the gratification of self-interest and a concern for others, fleeting experiences of awe redefine the self in terms of the collective, and orient our actions toward the needs of those around us.

You could make the case that our culture today is awe-deprived. Adults spend more and more time working and commuting and less time outdoors and with other people...Attendance at arts events — live music, theater, museums and galleries — has dropped over the years...Arts and music programs in schools are being dismantled in lieu of programs better suited to standardized testing; time outdoors and for novel, unbounded exploration are sacrificed for résumé-building activities.

We believe that awe deprivation has had a hand in a broad societal shift that has been widely observed over the past 50 years: People have become more individualistic, more self-focused, more materialistic and less connected to others. To reverse this trend, we suggest that people insist on experiencing more everyday awe, to actively seek out what gives them goose bumps, be it in looking at trees, night skies, patterns of wind on water or the quotidian nobility of others — the teenage punk who gives up his seat on public transportation, the young child who explores the world in a state of wonder, the person who presses on against all odds.

Lack of exercise disrupts body’s rhythms.

Natural daily rhythms in spontaneous movement patterns in both humans and mice show scale invariance, i.e., movement patterns repeat over time scales of minutes to hours. These scale invariant patterns decay with aging in both humans and mice, apparently correlating with progressive dysfunction of circadian pacemaker circuits in the brain's suprachiasmatic nucleus. Scheer and collaborators have now shown that in both aged and young mice exercise is a crucial variable. Loss of scale invariance associated with both inactivity and aging can be restored by exercise, even in old animals.

In healthy humans and other animals, behavioral activity exhibits scale invariance over multiple timescales from minutes to 24 h, whereas in aging or diseased conditions, scale invariance is usually reduced significantly. Accordingly, scale invariance can be a potential marker for health. Given compelling indications that exercise is beneficial for mental and physical health, we tested to what extent a lack of exercise affects scale invariance in young and aged animals. We studied six or more mice in each of four age groups (0.5, 1, 1.5, and 2 y) and observed an age-related deterioration of scale invariance in activity fluctuations. We found that limiting the amount of exercise, by removing the running wheels, leads to loss of scale-invariant properties in all age groups. Remarkably, in both young and old animals a lack of exercise reduced the scale invariance in activity fluctuations to the same level. We next showed that scale invariance can be restored by returning the running wheels. Exercise during the active period also improved scale invariance during the resting period, suggesting that activity during the active phase may also be beneficial for the resting phase. Finally, our data showed that exercise had a stronger influence on scale invariance than the effect of age. The data suggest that exercise is beneficial as revealed by scale-invariant parameters and that, even in young animals, a lack of exercise leads to strong deterioration in these parameters.

It’s not a stream of consciousness, its a rhythm.

In the NYTimes Gray Matter series Gregory Hickok gives an exegesis on the implications of his Psychological Science paper "The Rhythm of Perception." Some edited clips:

IN 1890, the American psychologist William James famously likened our conscious experience to the flow of a stream...recent research has shown that the “stream” of consciousness is, in fact, an illusion. We actually perceive the world in rhythmic pulses (brain waves that correlate with states like calm alertness and deep sleep) rather than as a continuous flow....We are exploring the possibility that brain rhythms are not merely a reflection of mental activity but a cause of it, helping shape perception, movement, memory and even consciousness itself...What this means is that the brain samples the world in rhythmic pulses, perhaps even discrete time chunks, much like the individual frames of a movie. From the brain’s perspective, experience is not continuous but quantized.

It turns out, for example, that our ability to detect a subtle event, like a slight change in a visual scene, oscillates over time, cycling between better and worse perceptual sensitivity several times a second. Research shows that these rhythms correlate with electrical rhythms of the brain.

If that’s hard to picture, here’s an analogy: Imagine trying to see an animal through a thick, swirling fog that varies in density as it drifts. The distinctness of the animal’s form will oscillate with the density of the fog, alternating between periods of relative clarity and opaqueness. According to recent experiments, this is how our perceptual systems sample the world — but rather than fog, it’s brain waves that drive the oscillations...Rhythms in the environment, such as those in music or speech, can draw neural oscillations into their tempo, effectively synchronizing the brain’s rhythms with those of the world around us.

In the study reported in Psychological Science Hickok and colleagues:

...presented listeners with a three-beat-per-second rhythm (a pulsing “whoosh” sound) for only a few seconds and then asked the listeners to try to detect a faint tone immediately afterward. The tone was presented at a range of delays between zero and 1.4 seconds after the rhythm ended. Not only did we find that the ability to detect the tone varied over time by up to 25 percent — that’s a lot — but it did so precisely in sync with the previously heard three-beat-per-second rhythm.

Why would the brain do this? One theory is that it’s the brain’s way of focusing attention. Picture a noisy cafe filled with voices, clanging dishes and background music. As you attend to one particular acoustic stream — say, your lunch mate’s voice — your brain synchronizes its rhythm to the rhythm of the voice and enhances the perceptibility of that stream, while suppressing other streams, which have their own, different rhythms. (More broadly, this kind of synchronization has been proposed as a mechanism for communication between neural networks within the brain.)

All of this points to the need for a new metaphor. We should talk of the “rhythm” of thought, of perception, of consciousness. Conceptualizing our mental experience this way is not only more accurate, but it also situates our mind within the broader context of the daily, monthly and yearly rhythms that dominate our lives.

Humans need not apply.

Check out this chilling video on the increasing obsolescence of humans, which was referenced in a recent meeting of the Chaos and Complexity Seminar group I attend at the University of Wisconsin (when I am in Madison during the warm months). Then note the partial solace offered by Carr's essay "Why Robots Will Always Need Us."