Tuesday, August 14, 2018

Rediscovering ancient greek music.

I want to point to a fascinating article by Armand D’Angour at Oxford University, on efforts to reconstruct what music sounded like in ancient Greece. The work is also described in this YouTube video:

Monday, August 13, 2018

Controlling drones with a body-machine interface.

On first glance this article creeped me out, because when control of drones at a distance is mentioned I think of the drones used to bomb ISIS or Al Quaeda cells controlled by operators in Tampa, FL. However, more benign or typical applications include deployments in environments where it is not desirable or possible to send a human operator, such as nuclear plants, scenes of natural hazards, or more generally in search and rescue missions. Also, the use of teleoperated systems can augment human dexterity and precision in fields such as minimally invasive surgery or microfabrication.

Miehlbradt et al. suggest an alternative to current control interfaces (frequently employing joysticks) that that require intensive practice. They have developed an intuitive gesture based interface for real and simulated drones. They recorded the upper-body kinematics and muscle activities during the generation of movements that would imitate the behavior of a flying drone. After identifying two main interaction strategies used by the participants, they assessed the capacity of potential users to actively steer the path of a virtual drone employing these two strategies. Eventually, they evaluated the transferability of the skills acquired during simulation training to the control of a real drone. Their abstract, and a video:
The accurate teleoperation of robotic devices requires simple, yet intuitive and reliable control interfaces. However, current human–machine interfaces (HMIs) often fail to fulfill these characteristics, leading to systems requiring an intensive practice to reach a sufficient operation expertise. Here, we present a systematic methodology to identify the spontaneous gesture-based interaction strategies of naive individuals with a distant device, and to exploit this information to develop a data-driven body–machine interface (BoMI) to efficiently control this device. We applied this approach to the specific case of drone steering and derived a simple control method relying on upper-body motion. The identified BoMI allowed participants with no prior experience to rapidly master the control of both simulated and real drones, outperforming joystick users, and comparing with the control ability reached by participants using the bird-like flight simulator Birdly.

Friday, August 10, 2018

No gender differences in early math cognition.

Kersey et al. have examined data from more than 500 children ranging in age from 6 months to 8 years across several tests of numerosity, counting, and elementary mathematics concepts. They found no differences in mathematical performance between boys and girls in any of the ages tested, suggesting that gender differences in STEM representation are unlikely to be due to intrinsic differences in cognitive ability.
Recent public discussions have suggested that the under-representation of women in science and mathematics careers can be traced back to intrinsic differences in aptitude. However, true gender differences are difficult to assess because sociocultural influences enter at an early point in childhood. If these claims of intrinsic differences are true, then gender differences in quantitative and mathematical abilities should emerge early in human development. We examined cross-sectional gender differences in mathematical cognition from over 500 children aged 6 months to 8 years by compiling data from five published studies with unpublished data from longitudinal records. We targeted three key milestones of numerical development: numerosity perception, culturally trained counting, and formal and informal elementary mathematics concepts. In addition to testing for statistical differences between boys’ and girls’ mean performance and variability, we also tested for statistical equivalence between boys’ and girls’ performance. Across all stages of numerical development, analyses consistently revealed that boys and girls do not differ in early quantitative and mathematical ability. These findings indicate that boys and girls are equally equipped to reason about mathematics during early childhood.

Thursday, August 09, 2018

A ecosystem of podcast bros who want to optimize your life.

I'm not a podcast or video kind of person, being too impatient to listen to or watch material that I can absorb more rapidly by reading about it. So, this piece by Molly Worthen describing a whole ecosystem of wellness gurus, a network of podcasters centered on Austin Texas and Southern California, was a revelation for me. (Note: this past November I did a post on an Austin based wellness project.) From her article:
...over the past few years the podcasters have become a significant cultural phenomenon, spiritual entrepreneurs who are filling the gap left as traditional religious organizations erode and modernity frays our face-to-face connections with communities and institutions...By my count, there are at least two dozen members of this podcast ecosystem...Several of these podcasters say they reach millions of listeners each month. In 2016, Joe Rogan put his figure “in the neighborhood of 30 million downloads per month”; his show is ranked second on the iTunes podcast chart, right behind Oprah.
In this secularized age of lonely seekers scrolling social media feeds, they have cultivated a spiritual community. They offer theologies and daily rituals of self-actualization, an appealing alternative to the rhetoric of victimhood and resentment that permeates both the right and the left...All this continues a long American tradition of self-help and creative, market-minded spirituality. The 19th century brimmed with gurus ready to guide you to other dimensions and prophets of the path from rags to riches.
Humans seem to be wired to seek salvation; even if polls suggest that more and more Americans reject traditional notions of God and skip church, it’s appealing to think that the latest lifestyle trend could be your path to existential bliss. The podcasters urge their listeners to experiment with fitness routines, diets, non-Western medicine, meditation and other “biohacks” to think more clearly, sleep more soundly and achieve professional success — and to quit blaming other people or bad luck for their problems.
Underlying this taste for experimentation is a deeper interest in evolutionary biology and psychology: the genes that, some experts believe, leave us programmed for a brutal, tribal, even pre-human past despite the creature comforts of the present...Evolutionary psychology is the secular answer to the doctrine of original sin: a primordial explanation for the anxieties that haunt us even if we have a decent job and a functional family...This is the podcast bro ethos: Ditch your ideologically charged identity. Accept your evolutionary programming. Take responsibility for mastering it, and find a cosmic purpose...Many have a strong interest in spirituality, and see practices like Buddhist meditation or consuming hallucinogenic “plant medicine” as not just a way to improve daily performance, but a path to something deeper.
The common thread linking the podcasters’ interest in evolutionary psychology and their metaphysical dabbling is the quest to transcend the ego, and to overcome the idea that we are personally aggrieved by enemies wholly unlike ourselves. This means mistrusting ideology and identitarian politics...having a one-world tribe, a tribe of human beings, period, is really what’s going to heal us for our next stage of life as a species on this planet.
Is this a postmodern monastic order, passing on breakfast and shivering in the shower while pondering the next step in mastering the ego? These podcasters lead one of the largest quasi-spiritual self-help “denominations” in the United States. It is a far-flung virtual community that gives people solace, a regimen and a sense of like-mindedness at a time when churches and other old-fashioned institutions simultaneously seem to ask too much, yet also fail to provide many people with whatever they’re looking for. The podcasters’ rejection of culture-wars partisanship resonates at a time when many Americans have stopped participating in politics (every listener I spoke to avoids political media the way they avoid, well, non-kale smoothies).
Yet podcasts are not churches. They are not political parties. They don’t patch over the existential void so much as reveal how avidly we yearn to fill it...The podcasters may offer a lesson to politicians and activists: to build a following, find a way to provide the sense of affiliation, daily rhythm and ultimate purpose that humans crave. Slogans of victimhood and grievance may rile up the base. But most people yearn, instead, for a sense of belonging and a path to mastery — even if it starts with a cold shower.

Wednesday, August 08, 2018

Our weaponized social media

I pass on a few clips from a sobering NYTimes article by Kara Swisher, who quotes from a recent Facebook post:
We face determined, well-funded adversaries who will never give up and are constantly changing tactics. It’s an arms race and we need to constantly improve too.
Continuing,
Facebook, as well as Twitter and Google’s YouTube, have become the digital arms dealers of the modern age...by weaponizing pretty much everything that could be weaponized. They have mutated human communication, so that connecting people has too often become about pitting them against one another, and turbocharged that discord to an unprecedented and damaging volume...They have weaponized social media. They have weaponized the First Amendment. They have weaponized civic discourse. And they have weaponized, most of all, politics.
Swisher's concluding paragraphs:
“I mean, my emotion is feeling a deep sense of responsibility to try to fix the problem,” said Mr. Zuckerberg. “In running a company, if you want to be innovative and advance things forward, I think you have to be willing to get some things wrong. But I don’t think it is acceptable to get the same things wrong over and over again.”
It was a classic Silicon Valley engineer’s roll-up-your-sleeves answer, which leaves many cold when it comes to, say, the manipulation of democracy. Fending off bad actors like the Russians has been and will be increasingly expensive; it may even be impossible. But Facebook could have done much more than it did, and it certainly needs to do more than it’s doing.
Mr. Zuckerberg is now trying to fend off talk in Washington of regulating his company like the thing he once told me it was: a utility. He has also spent the last month meeting over dinners with a range of academic experts on free speech, propaganda and more to try to understand where to go from here.
Call it the education of Mark Zuckerberg and Silicon Valley, but on the world’s dime. How much that has — and will — cost is probably immeasurable.

Tuesday, August 07, 2018

How pupil mimicry promotes trust.

Prochazkova et al. show that pupil mimicry promotes trust through our theory of mind brain network:

Significance
Trusting others is central for cooperative endeavors to succeed. To decide whether to trust or not, people generally make eye contact. As pupils of interaction partners align, mimicking pupil size helps them to make well-informed trust decisions. How the brain integrates information from the partner and from their own bodily feedback to make such decisions was unknown because previous research investigated these processes separately. Herein, we take a multimethod approach and demonstrate that pupil mimicry is regulated by the theory-of-mind network, and informs decisions of trust by activating the precuneus. This evolutionary ancient neurophysiological mechanism that is active in human adults, infants, and chimpanzees promotes affiliation, bonding, and trust through mimicry.
Abstract
The human eye can provide powerful insights into the emotions and intentions of others; however, how pupillary changes influence observers’ behavior remains largely unknown. The present fMRI–pupillometry study revealed that when the pupils of interacting partners synchronously dilate, trust is promoted, which suggests that pupil mimicry affiliates people. Here we provide evidence that pupil mimicry modulates trust decisions through the activation of the theory-of-mind network (precuneus, temporo-parietal junction, superior temporal sulcus, and medial prefrontal cortex). This network was recruited during pupil-dilation mimicry compared with interactions without mimicry or compared with pupil-constriction mimicry. Furthermore, the level of theory-of-mind engagement was proportional to individual’s susceptibility to pupil-dilation mimicry. These data reveal a fundamental mechanism by which an individual’s pupils trigger neurophysiological responses within an observer: when interacting partners synchronously dilate their pupils, humans come to feel reflections of the inner states of others, which fosters trust formation.

Monday, August 06, 2018

Brain regions involved in compensating for lost body parts.

From Striem-Amit et al.:

Significance
What determines the role of brain regions and their plasticity when typical inputs or experience is not provided? To what extent can extreme compensatory use affect brain organization? We tested the reorganization of primary and association sensorimotor cortex hand-selective areas in people born without hands, who use their feet for everyday tasks. We found that their primary sensorimotor hand area is preferentially activated for nearby body parts that cannot serve as effectors. In contrast, foot-selective compensatory plasticity was found in the association cortex, in an area typically involved in manual tool use. This shows limitations of compensatory plasticity and experience in modifying brain organization of early topographical cortex, as compared with association cortices where function-based organization is the driving factor.
Abstract
What forces direct brain organization and its plasticity? When brain regions are deprived of their input, which regions reorganize based on compensation for the disability and experience, and which regions show topographically constrained plasticity? People born without hands activate their primary sensorimotor hand region while moving body parts used to compensate for this disability (e.g., their feet). This was taken to suggest a neural organization based on functions, such as performing manual-like dexterous actions, rather than on body parts, in primary sensorimotor cortex. We tested the selectivity for the compensatory body parts in the primary and association sensorimotor cortex of people born without hands (dysplasic individuals). Despite clear compensatory foot use, the primary sensorimotor hand area in the dysplasic subjects showed preference for adjacent body parts that are not compensatorily used as effectors. This suggests that function-based organization, proposed for congenital blindness and deafness, does not apply to the primary sensorimotor cortex deprivation in dysplasia. These findings stress the roles of neuroanatomical constraints like topographical proximity and connectivity in determining the functional development of primary cortex even in extreme, congenital deprivation. In contrast, increased and selective foot movement preference was found in dysplasics’ association cortex in the inferior parietal lobule. This suggests that the typical motor selectivity of this region for manual actions may correspond to high-level action representations that are effector-invariant. These findings reveal limitations to compensatory plasticity and experience in modifying brain organization of early topographical cortex compared with association cortices driven by function-based organization.

Friday, August 03, 2018

Residential isolation of disadvantaged groups is not mitigated by extensive urban mobility.

Wang et al. offer yet another approach to observing the intractability of racial segregation in large cities:

Significance
Living in disadvantaged neighborhoods is widely assumed to undermine life chances because residents are isolated from neighborhoods with greater resources. Yet, residential isolation may be mitigated by individuals spending much of their everyday lives outside their home neighborhoods, a possibility that has been difficult to assess on a large scale. Using new methods to analyze urban mobility in the 50 largest American cities, we find that residents of primarily black and Hispanic neighborhoods—whether poor or not—are far less exposed to either nonpoor or white middle-class neighborhoods than residents of primarily white neighborhoods. Although residents of disadvantaged neighborhoods regularly travel as far and to as many different neighborhoods as those from advantaged neighborhoods, their relative isolation and segregation persist.
Abstract
Influential research on the negative effects of living in a disadvantaged neighborhood assumes that its residents are socially isolated from nonpoor or “mainstream” neighborhoods, but the extent and nature of such isolation remain in question. We develop a test of neighborhood isolation that improves on static measures derived from commonly used census reports by leveraging fine-grained dynamic data on the everyday movement of residents in America’s 50 largest cities. We analyze 650 million geocoded Twitter messages to estimate the home locations and travel patterns of almost 400,000 residents over 18 mo. We find surprisingly high consistency across neighborhoods of different race and income characteristics in the average travel distance (radius) and number of neighborhoods traveled to (spread) in the metropolitan region; however, we uncover notable differences in the composition of the neighborhoods visited. Residents of primarily black and Hispanic neighborhoods—whether poor or not—are far less exposed to either nonpoor or white middle-class neighborhoods than residents of primarily white neighborhoods. These large racial differences are notable given recent declines in segregation and the increasing diversity of American cities. We also find that white poor neighborhoods are substantially isolated from nonpoor white neighborhoods. The results suggest that even though residents of disadvantaged neighborhoods travel far and wide, their relative isolation and segregation persist.

Thursday, August 02, 2018

Chimps can psych out humans

Interesting work from Eckert et al. shows that chimps can use mental state information revealed by experimenters' biases in selecting food items.
Great apes have been shown to be intuitive statisticians: they can use proportional information within a population to make intuitive probability judgments about randomly drawn samples [unpublished data]. Humans, from early infancy onward, functionally integrate intuitive statistics with other cognitive domains to judge the randomness of an event. To date, nothing is known about such cross-domain integration in any nonhuman animal, leaving uncertainty about the origins of human statistical abilities. We investigated whether chimpanzees take into account information about psychological states of experimenters (their biases and visual access) when drawing statistical inferences. We tested 21 sanctuary-living chimpanzees in a previously established paradigm that required subjects to infer which of two mixed populations of preferred and non-preferred food items was more likely to lead to a desired outcome for the subject. In a series of three experiments, we found that chimpanzees chose based on proportional information alone when they had no information about experimenters’ preferences and (to a lesser extent) when experimenters had biases for certain food types but drew blindly. By contrast, when biased experimenters had visual access, subjects ignored statistical information and instead chose based on experimenters’ biases. Lastly, chimpanzees intuitively used a violation of statistical likelihoods as indication for biased sampling. Our results suggest that chimpanzees have a random sampling assumption that can be overridden under the appropriate circumstances and that they are able to use mental state information to judge whether this is necessary. This provides further evidence for a shared statistical inference mechanism in apes and humans.

Wednesday, August 01, 2018

Enhanced brain activity associated with highly superior memory.

Santangelo et al. show that people with superior memory have enhanced connectivity of their prefrontal cortex with their hippocampus and temporoparietal junction:

Significance
Recent research has identified human subjects who have highly superior autobiographical memory (HSAM). Here, we investigated, using fMRI, the neural activation induced by retrieval of autobiographical memories (AMs) and semantic memories (SMs) in subjects with HSAM and control subjects. While their brains were being scanned, subjects had to retrieve AMs as well as SMs (e.g., examples of animals). The subjects with HSAM displayed a superior ability to retrieve details of AMs, supported by enhanced activation of several brain regions, including the medial prefrontal cortex and temporoparietal junction, as well as increased connectivity of the prefrontal cortex with the hippocampus, a region well known to be involved in memory representation. These findings suggest that activation of these systems may play a critical role in enabling HSAM.
Abstract
Brain systems underlying human memory function have been classically investigated studying patients with selective memory impairments. The discovery of rare individuals who have highly superior autobiographical memory (HSAM) provides, instead, an opportunity to investigate the brain systems underlying enhanced memory. Here, we carried out an fMRI investigation of a group of subjects identified as having HSAM. During fMRI scanning, eight subjects with HSAM and 21 control subjects were asked to retrieve autobiographical memories (AMs) as well as non-AMs (e.g., examples of animals). Subjects were instructed to signal the “access” to an AM by a key press and to continue “reliving” it immediately after. Compared with controls, individuals with HSAM provided a richer AM recollection and were faster in accessing AMs. The access to AMs was associated with enhanced prefrontal/hippocampal functional connectivity. AM access also induced increased activity in the left temporoparietal junction and enhanced functional coupling with sensory cortices in subjects with HSAM compared with controls. In contrast, subjects with HSAM did not differ from controls in functional activity during the reliving phase. These findings, based on fMRI assessment, provide evidence of interaction of brain systems engaged in memory retrieval and suggest that enhanced activity of these systems is selectively involved in enabling more efficient access to past experiences in HSAM.

Tuesday, July 31, 2018

Are things getting better or worse?

In a recent New Yorker article Joshua Rothman discusses debate over assessing the state of the world, with major emphasis on Pinker book "Enlightenment Now", which was the subject of a series of MindBlog posts March 1 - March 12 of this year. Things like "Progressophobia" on the part of intellectuals, people seeing the past through rose colored glasses, and media emphasizing momentary crises over long term trends lead most people to think that the world is getting worse rather than better, which, Pinker says, is "wrong wrong, flat-earth wrong."

Rothman's brief reviews of a number of other books debating progress and optimism versus pessimism about the future make his article well worth reading. I'll pass on the end of the article (note especially the last paragraph), which points to a book by Hans Rosling:
In “Factfulness: Ten Reasons We’re Wrong About the World—and Why Things Are Better Than You Think,” the Swedish global-health statistician Hans Rosling, who wrote the book with his son and daughter-in-law, tries to find such a picture. Most depictions of the world, Rosling thinks, are either too optimistic or too pessimistic; if they don’t succumb to despair, they seem to look too quickly away from suffering. Rosling adopts a mantra—“Bad and better”—to avoid these extremes. “Think of the world as a premature baby in an incubator,” he suggests:
The baby’s health status is extremely bad, and her breathing, heart rate, and other important signs are tracked constantly so that changes for better or worse can quickly be seen. After a week, she is getting a lot better. On all the main measures, she is improving, but she still has to stay in the incubator because her health is still critical. Does it make sense to say that the infant’s situation is improving? Yes. Absolutely. Does it make sense to say it is bad? Yes, absolutely. Does saying “things are improving” imply that everything is fine, and we should all relax and not worry? No, not at all. Is it helpful to have to choose between bad and improving? Definitely not. It’s both. It’s both bad and better. Better, and bad, at the same time. . . . That is how we must think about the current state of the world.
Rosling’s image captures many of the perplexities of our collective situation. We desperately want the baby to survive. We also know that survival doesn’t guarantee happiness. The baby is struggling, and suffering, and will continue to do so; as a result, we’re more likely to be happy for her than she is to be happy for herself. (Pinker, similarly, is happier for us than we are.) It’s possible, moreover, that she’ll be saved only temporarily. No one is ever truly out of the woods.
In the meantime, the baby’s survival depends on the act of diagnosis. Until her ailments are identified, they can’t be cured. Problems and progress are inextricable, and the history of improvement is also the history of problem-discovery. Diagnosis, of course, is an art in itself; it’s possible to misunderstand problems, or to overstate them, and, in doing so, to make them worse. But a world in which no one complained—in which we only celebrated how good we have it—would be a world that never improved. The spirit of progress is also the spirit of discontent.

Monday, July 30, 2018

Piano training enhances speech perception.

Fascinating work from an international collaboration of Desimone at M.I.T., Nan at Beijing Normal Univ., and others:

Significance
Musical training is beneficial to speech processing, but this transfer’s underlying brain mechanisms are unclear. Using pseudorandomized group assignments with 74 4- to 5-year-old Mandarin-speaking children, we showed that, relative to an active control group which underwent reading training and a no-contact control group, piano training uniquely enhanced cortical responses to pitch changes in music and speech (as lexical tones). These neural enhancements further generalized to early literacy skills: Compared with the controls, the piano-training group also improved behaviorally in auditory word discrimination, which was correlated with their enhanced neural sensitivities to musical pitch changes. Piano training thus improves children’s common sound processing, facilitating certain aspects of language development as much as, if not more than, reading instruction.
Abstract
Musical training confers advantages in speech-sound processing, which could play an important role in early childhood education. To understand the mechanisms of this effect, we used event-related potential and behavioral measures in a longitudinal design. Seventy-four Mandarin-speaking children aged 4–5 y old were pseudorandomly assigned to piano training, reading training, or a no-contact control group. Six months of piano training improved behavioral auditory word discrimination in general as well as word discrimination based on vowels compared with the controls. The reading group yielded similar trends. However, the piano group demonstrated unique advantages over the reading and control groups in consonant-based word discrimination and in enhanced positive mismatch responses (pMMRs) to lexical tone and musical pitch changes. The improved word discrimination based on consonants correlated with the enhancements in musical pitch pMMRs among the children in the piano group. In contrast, all three groups improved equally on general cognitive measures, including tests of IQ, working memory, and attention. The results suggest strengthened common sound processing across domains as an important mechanism underlying the benefits of musical training on language processing. In addition, although we failed to find far-transfer effects of musical training to general cognition, the near-transfer effects to speech perception establish the potential for musical training to help children improve their language skills. Piano training was not inferior to reading training on direct tests of language function, and it even seemed superior to reading training in enhancing consonant discrimination.

Friday, July 27, 2018

Mechanism of white matter changes induced by meditation?

Posner and collaborators, who previously have shown changes in brain white matter induced by meditation, suggest a possible mechanism, using a mouse model.
Meditation has been shown to modify brain connections. However, the cellular mechanisms by which this occurs are not known. We hypothesized that changes in white matter found following meditation may be due to increased rhythmicity observed in frontal areas in the cortex. The current study in mice tested this directly by rhythmically stimulating cells in the frontal midline. We found that such stimulation caused an increase in connectivity due to changes in the axons in the corpus callosum, which transmit impulses to and from the frontal midline. This work provides a plausible but not proven mechanism through which a mental activity such as meditation can improve brain connectivity.

Thursday, July 26, 2018

The neuroscience of mindfulness meditation

I completely missed this review article by Posner and colleagues when it appeared, and am grateful for Bäumli's mention of it in her recent brief essay, which gives this link for downloading it. It has a mind numbing amount of information on research into the brain correlates of meditative practice and competence, summary tables, references, graphics. In this post I'm passing passing on the summary of key points and one graphic:

Key points
It is proposed that the mechanism through which mindfulness meditation exerts its effects is a process of enhanced self-regulation, including attention control, emotion regulation and self-awareness.
Research on mindfulness meditation faces a number of important challenges in study design that limit the interpretation of existing studies.
A number of changes in brain structure have been related to mindfulness meditation.
Mindfulness practice enhances attention. The anterior cingulate cortex is the region associated with attention in which changes in activity and/or structure in response to mindfulness meditation are most consistently reported.
Mindfulness practice improves emotion regulation and reduces stress. Fronto-limbic networks involved in these processes show various patterns of engagement by mindfulness meditation.
Meditation practice has the potential to affect self-referential processing and improve present-moment awareness. The default mode networks — including the midline prefrontal cortex and posterior cingulate cortex, which support self-awareness — could be altered following mindfulness training.
Mindfulness meditation has potential for the treatment of clinical disorders and might facilitate the cultivation of a healthy mind and increased well-being.
Future research into mindfulness meditation should use randomized and actively controlled longitudinal studies with large sample sizes to validate previous findings.
The effects of mindfulness practice on neural structure and function need to be linked to behavioural performance, such as cognitive, affective and social functioning, in future research.
The complex mental state of mindfulness is likely to be supported by the large-scale brain networks; future work should take this into account rather than being restricted to activations in single brain areas.

Legend - Schematic view of some of the brain regions involved in attention control (the anterior cingulate cortex and the striatum), emotion regulation (multiple prefrontal regions, limbic regions and the striatum) and self-awareness (the insula, medial prefrontal cortex and posterior cingulate cortex and precuneus).

Wednesday, July 25, 2018

When persistence doesn't pay - the sunk cost bias.

Sweis et al. show that sensitivity to time invested in pursuit of a reward occurs similarly in mice, rats, and humans. All three display a resistance to giving up their pursuit of a reward in a foraging context, but only after they have made the decision to pursue the reward. They suggest that there are two independent valuation processes, one assessing whether to accept an offer and the other — the one that is susceptible to sunk costs — assessing whether to continue investing in the choice. Their abstract:
Sunk costs are irrecoverable investments that should not influence decisions, because decisions should be made on the basis of expected future consequences. Both human and nonhuman animals can show sensitivity to sunk costs, but reports from across species are inconsistent. In a temporal context, a sensitivity to sunk costs arises when an individual resists ending an activity, even if it seems unproductive, because of the time already invested. In two parallel foraging tasks that we designed, we found that mice, rats, and humans show similar sensitivities to sunk costs in their decision-making. Unexpectedly, sensitivity to time invested accrued only after an initial decision had been made. These findings suggest that sensitivity to temporal sunk costs lies in a vulnerability distinct from deliberation processes and that this distinction is present across species.

Tuesday, July 24, 2018

Declining mental health among disadvantaged Americans.

Cherlin summarizes work by Goldman et al. that demonstrates "a troubling portrait of declining psychological health among non-Hispanic whites in mid- and later-life between the mid-1990s and the early 2010s... Equally troubling is the concentration of these declines among individuals with lower SES (socioeconomic status...life satisfaction declined for people at the 10th, 25th, and 50th percentiles of SES, remained constant for people at the 75th percentile, and increased for people at the 90th percentile. To the list of widening inequalities in the United States, which center on economic inequality, we must now add inequality in psychological health.

The Goldman et al. Abstract:

Significance
In the past few years, references to the opioid epidemic, drug poisonings, and associated feelings of despair among Americans, primarily working-class whites, have flooded the media, and related patterns of mortality have been of increasing interest to social scientists. Yet, despite recurring references to distress or despair in journalistic accounts and academic studies, there has been little analysis of whether psychological health among American adults has worsened over the past two decades. Here, we use data from national samples of adults in the mid-1990s and early 2010s to demonstrate increasing distress and declining well-being that was concentrated among low-socioeconomic-status individuals but spanned the age range from young to older adults.
Abstract
Although there is little dispute about the impact of the US opioid epidemic on recent mortality, there is less consensus about whether trends reflect increasing despair among American adults. The issue is complicated by the absence of established scales or definitions of despair as well as a paucity of studies examining changes in psychological health, especially well-being, since the 1990s. We contribute evidence using two cross-sectional waves of the Midlife in the United States (MIDUS) study to assess changes in measures of psychological distress and well-being. These measures capture negative emotions such as sadness, hopelessness, and worthlessness, and positive emotions such as happiness, fulfillment, and life satisfaction. Most of the measures reveal increasing distress and decreasing well-being across the age span for those of low relative socioeconomic position, in contrast to little decline or modest improvement for persons of high relative position.

Monday, July 23, 2018

Therapy for NYTAD - read about citrus micro-jets!

What is NYTAD? My just made up acronym for “New York Times Anxiety Disorder” - what I have to resist during my daily glance through the endless list of NYT and WaPo articles on the awful human being who serves as our president. And then, unexpectedly, a point of light. A neat article about something else: the microjets of citrus oil you see when you squeeze the skin of an orange or lemon. It turns out that the layered construction of the citrus exocarp allows for the buildup of fluid pressure in citrus oil gland reservoirs and their subsequent explosive rupture . I'll pass on the abstract of the PNAS article to which it refers, which gives the interesting details, along with a video.

Significance
Here we show a unique, natural method for microscale jetting of fluid made possible by the tuning of material properties from which the jets emanate. The composite, layered construction of the citrus exocarp allows for the buildup of fluid pressure in citrus oil gland reservoirs and their subsequent explosive rupture. Citrus jetting has not been documented in literature, and its purpose is unknown. This method for microscale fluid dispersal requires no auxiliary equipment and may open avenues for new methods of medicine and chemical delivery. We show how jet kinematics are related to substrate properties and reservoir shape.
Abstract
The rupture of oil gland reservoirs housed near the outer surface of the citrus exocarp is a common experience to the discerning citrus consumer and bartenders the world over. These reservoirs often rupture outwardly in response to bending the peel, which compresses the soft material surrounding the reservoirs, the albedo, increasing fluid pressure in the reservoir. Ultimately, fluid pressure exceeds the failure strength of the outermost membrane, the flavedo. The ensuing high-velocity discharge of oil and exhaustive emptying of oil gland reservoirs creates a method for jetting small quantities of the aromatic oil. We compare this jetting behavior across five citrus hybrids through high-speed videography. The jetting oil undergoes an extreme acceleration to reach velocities in excess of 10 m/s. Through material characterization and finite element simulations, we rationalize the combination of tuned material properties and geometries enabling the internal reservoir pressures that produce explosive dispersal, finding the composite structure of the citrus peel is critical for microjet production.

Friday, July 20, 2018

Crows make mental templates.

Weintraub points to further studies from the University of Aukland School of Psychology on the extraordinary New Caledonian crows that have been shown to learn tool use. They also appear to use “mental template matching” - forming an image in their heads of tools they have seen used by others, and then copying them.

 

Thursday, July 19, 2018

Perceptual and judgement creep.

Fascinating work by Gilbert and colleagues:
Why do some social problems seem so intractable? In a series of experiments, we show that people often respond to decreases in the prevalence of a stimulus by expanding their concept of it. When blue dots became rare, participants began to see purple dots as blue; when threatening faces became rare, participants began to see neutral faces as threatening; and when unethical requests became rare, participants began to see innocuous requests as unethical. This “prevalence-induced concept change” occurred even when participants were forewarned about it and even when they were instructed and paid to resist it. Social problems may seem intractable in part because reductions in their prevalence lead people to see more of them.


Wednesday, July 18, 2018

Authentic lies.

Hahl et al. suggest how a blatantly lying demagogue (guess who?) can be perceived as authentic:
We develop and test a theory to address a puzzling pattern that has been discussed widely since the 2016 U.S. presidential election and reproduced here in a post-election survey: how can a constituency of voters find a candidate “authentically appealing” (i.e., view him positively as authentic) even though he is a “lying demagogue” (someone who deliberately tells lies and appeals to non-normative private prejudices)? Key to the theory are two points: (1) “common-knowledge” lies may be understood as flagrant violations of the norm of truth-telling; and (2) when a political system is suffering from a “crisis of legitimacy” with respect to at least one political constituency, members of that constituency will be motivated to see a flagrant violator of established norms as an authentic champion of its interests. Two online vignette experiments on a simulated college election support our theory. These results demonstrate that mere partisanship is insufficient to explain sharp differences in how lying demagoguery is perceived, and that several oft-discussed factors—information access, culture, language, and gender—are not necessary for explaining such differences. Rather, for the lying demagogue to have authentic appeal, it is sufficient that one side of a social divide regards the political system as flawed or illegitimate.