Top-down alpha band oscillations optimize visual perception.

Interesting work from Samaha et al.:

Significance

In contrast to canonical, stimulus-driven models of perception, recent proposals argue that perceptual experiences are constructed in an active manner in which top-down influences play a key role. In particular, predictions that the brain makes about the world are incorporated into each perceptual experience. Because forming the appropriate sensory predictions can have a large impact on our visual experiences and visually guided behaviors, a mechanism thought to be disrupted in certain neurological conditions like autism and schizophrenia, an understanding of the neural basis of these predictions is critical. Here, we provide evidence that perceptual expectations about when a stimulus will appear are instantiated in the brain by optimally configuring prestimulus alpha-band oscillations so as to make subsequent processing most efficacious.

Abstract

The physiological state of the brain before an incoming stimulus has substantial consequences for subsequent behavior and neural processing. For example, the phase of ongoing posterior alpha-band oscillations (8–14 Hz) immediately before visual stimulation has been shown to predict perceptual outcomes and downstream neural activity. Although this phenomenon suggests that these oscillations may phasically route information through functional networks, many accounts treat these periodic effects as a consequence of ongoing activity that is independent of behavioral strategy. Here, we investigated whether alpha-band phase can be guided by top-down control in a temporal cueing task. When participants were provided with cues predictive of the moment of visual target onset, discrimination accuracy improved and targets were more frequently reported as consciously seen, relative to unpredictive cues. This effect was accompanied by a significant shift in the phase of alpha-band oscillations, before target onset, toward each participant’s optimal phase for stimulus discrimination. These findings provide direct evidence that forming predictions about when a stimulus will appear can bias the phase of ongoing alpha-band oscillations toward an optimal phase for visual processing, and may thus serve as a mechanism for the top-down control of visual processing guided by temporal predictions.

Universal features of human music.

I have read through a fascinating paper by Savage et al. that makes a convincing case for statistical universals in the structure and function of human music. I pass on the abstract and a few clips from the text. Motivated readers can request a PDF of the article from me.

Music has been called “the universal language of mankind.” Although contemporary theories of music evolution often invoke various musical universals, the existence of such universals has been disputed for decades and has never been empirically demonstrated. Here we combine a music-classification scheme with statistical analyses, including phylogenetic comparative methods, to examine a well-sampled global set of 304 music recordings. Our analyses reveal no absolute universals but strong support for many statistical universals that are consistent across all nine geographic regions sampled. These universals include 18 musical features that are common individually as well as a network of 10 features that are commonly associated with one another. They span not only features related to pitch and rhythm that are often cited as putative universals but also rarely cited domains including performance style and social context. These cross-cultural structural regularities of human music may relate to roles in facilitating group coordination and cohesion, as exemplified by the universal tendency to sing, play percussion instruments, and dance to simple, repetitive music in groups. Our findings highlight the need for scientists studying music evolution to expand the range of musical cultures and musical features under consideration. The statistical universals we identified represent important candidates for future investigation.

The 18 universal features:

Pitch: Music tends to use discrete pitches (1) to form nonequidistant scales (2) containing seven or fewer scale degrees per octave (3). Music also tends to use descending or arched melodic contours (4) composed of small intervals (5) of less than 750 cents (i.e., a perfect fifth or smaller).

Rhythm: Music tends to use an isochronous beat (6) organized according to metrical hierarchies (7) based on multiples of two or three beats (8)—especially multiples of two beats (9). This beat tends to be used to construct motivic patterns (10) based on fewer than five durational values (11).

Form: Music tends to consist of short phrases (12) less than 9 s long.

Instrumentation: Music tends to use both the voice (13) and (nonvocal) instruments (14), often together in the form of accompanied vocal song.

Performance style: Music tends to use the chest voice (i.e., modal register) (15) to sing words (16), rather than vocables (nonlexical syllables).

Social context: Music tends to be performed predominantly in groups (17) and by males (18). The bias toward male performance is true of singing, but even more so of instrumental performance.

The geographic distribution of the recordings analyzed:

The 304 recordings from the Garland Encyclopedia of World Music show a widespread geographic distribution. They are grouped into nine regions specified a priori by the Encyclopedia’s editors, as color-coded in the legend at bottom: North America (n = 33 recordings), Central/South America (39), Europe (40), Africa (21), the Middle East (35), South Asia (34), East Asia (34), Southeast Asia (14), and Oceania (54).

A small bonbon for techie MindBlog readers.

Passed on to me by a friend... still vaporware, but cute.

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.