My grandsons - making it in the brave new world - part I

I will be going soon to Austin Texas, to spend the holiday with my son's family, who live in the same house I grew up in. Every grandfather says this, but I have to also say a how incredulous I am at the vastly different a world my two year old grandson and his younger brother will face than the one I grew up in, a period of continuously expanding opportunities from the late 1940s to the late 1960s. The same Univ. of Wisconsin assistant professorship I took as a 27 year old would now go only to someone much older, who would most likely have to settle for a non-tenure position, if even that were available. With the partition of our economy into a service sector whose employees can't support a family and an educated, computer savvy, creative, managing elite, an extraordinary set of skill are now required to 'make it.' David Brooks presents a list of mental types that might thrive in a world in which we we must interface with intelligent machines:

Freestylers - who can play with the computer but know when to overrule it (as you sometimes overrule your GPS in neighborhoods you are familiar with).

Synthesizers - who surf vast amounts of data to crystallize a pattern or story.

Humanizers - who make the human-machine interplay feel more natural.

Conceptual engineers - who come up with creative methods to think about unexpected problems.

Motivators - who can inspire efforts on behalf of machines that are more naturally generated in the service of other humans.

Moralizers - who keep performance metrics from being reduced to productivity statistics that devalue personal moral traits like loyalty and end up destroying morale and social capital.

Greeters - who provide personalized services to the 15 percent of workers who 'make it' (have lots of disposable income).

Economizers - who advise the bottom 85 percent how to preserve rich lives on a small income.

Weavers - who try to deal with the social disintegration, disaffected lifestyles, that are a consequence of the inegalitarian facts of this new world.

Sequence your microbiome!

Some months ago I paid 23andMe about a $100 to analyze a mouth swab of epithelial cell and report back information on my genetic makeup, ancestry, health risks, etc. I was particularly interested in the SNPs (single nucleotide polymorphisms) that correlate with more or less risk for things like heart disease, alzheimer’s, etc. (The FDA has recently shut down their releasing that information to new subscribers because they have decided it is an untested medical diagnostic procedure.)

I want now to mention another neat test you can purchase for ~$100, where you send in a swab of your poop, mouth , and skin and are sent back information on your microbiome, the genes of hundreds of microbial species (microbiota) that share your body with you. Michael Pollan, the guy who has written best selling food books (Omnivore’s Dilemma, etc.) has done an engaging piece on this. Some clips:

To the extent that we are bearers of genetic information, more than 99 percent of it is microbial. And it appears increasingly likely that this “second genome,” as it is sometimes called, exerts an influence on our health as great and possibly even greater than the genes we inherit from our parents. But while your inherited genes are more or less fixed, it may be possible to reshape, even cultivate, your second genome.

Disorders in our internal ecosystem — a loss of diversity, say, or a proliferation of the “wrong” kind of microbes — may predispose us to obesity and a whole range of chronic diseases, as well as some infections. “Fecal transplants,” which involve installing a healthy person’s microbiota into a sick person’s gut, have been shown to effectively treat an antibiotic-resistant intestinal pathogen named C. difficile, which kills 14,000 Americans each year....[there is concern] about the damage that antibiotics, even in tiny doses, are doing to the microbiome — and particularly to our immune system and weight. “Farmers have been performing a great experiment for more than 60 years...by giving subtherapeutic doses of antibiotics to their animals to make them gain weight...the “Westernized microbiome” most of us now carry around is in fact an artifact of civilization”

...a pristine microbiome — of people who have had little or no contact with Westerners — features much greater biodiversity, including a number of species never before sequenced, and ... much higher levels of prevotella than is typically found in the Western gut....these vibrant, diverse and antibiotic-naïve microbiomes may play a role in Amerindians’ markedly lower rates of allergies, asthma, atopic disease and chronic conditions like Type 2 diabetes and cardiovascular disease.

The successful gardener has always known you don’t need to master the science of the soil, which is yet another hotbed of microbial fermentation, in order to nourish and nurture it. You just need to know what it likes to eat — basically, organic matter — and how, in a general way, to align your interests with the interests of the microbes and the plants. The gardener also discovers that, when pathogens or pests appear, chemical interventions “work,” that is, solve the immediate problem, but at a cost to the long-term health of the soil and the whole garden. The drive for absolute control leads to unanticipated forms of disorder.

This, it seems to me, is pretty much where we stand today with respect to our microbiomes — our teeming, quasi-wilderness. We don’t know a lot, but we probably know enough to begin taking better care of it. We have a pretty good idea of what it likes to eat, and what strong chemicals do to it. We know all we need to know, in other words, to begin, with modesty, to tend the unruly garden within.

Psychobiotics - gut bacteria changing our brains?

Walking through the aisles of my local health food store, the Williamson Street Co-op, I’ve often been tempted by the claims of exotic yoghurts and “probiotic” drinks like Kefir, that contain strains of Lactobacillus and a number of other “good” bacteria. It turns out a number of these bugs produce and release into our gut neuroactive compounds such as GABA, an inhibitory neurotransmitter, and serotonin, a mood regulator. Dinan et al. do a review article on what they term psychobiotics (organisms that alleviate psychiatric illness)

Here, we define a psychobiotic as a live organism that, when ingested in adequate amounts, produces a health benefit in patients suffering from psychiatric illness. As a class of probiotic, these bacteria are capable of producing and delivering neuroactive substances such as gamma-aminobutyric acid and serotonin, which act on the brain-gut axis. Preclinical evaluation in rodents suggests that certain psychobiotics possess antidepressant or anxiolytic activity. Effects may be mediated via the vagus nerve, spinal cord, or neuroendocrine systems. So far, psychobiotics have been most extensively studied in a liaison psychiatric setting in patients with irritable bowel syndrome, where positive benefits have been reported for a number of organisms including Bifidobacterium infantis. Evidence is emerging of benefits in alleviating symptoms of depression and in chronic fatigue syndrome. Such benefits may be related to the anti-inflammatory actions of certain psychobiotics and a capacity to reduce hypothalamic-pituitary-adrenal axis activity. Results from large scale placebo-controlled studies are awaited.

Three psychological regions of the U.S. - economic, health, social, political correlates

Rentfrow and collaborators probe the possibility of dividing regions of the United States, not in terms of traditional social and economic indicators, but in terms of psychological characteristics instead. It seems reasonable that psychological factors would underlie higher level outcomes such as social and economic indicators.

...the present work aimed to determine whether it is possible to construct a map of the United States based entirely on psychological characteristics, in this case personality traits. What would such a map look like? And how would its individual regions vary in terms of key political, economic, social, and health (PESH) metrics known to vary geographically within countries?

The analysis was at a state level, covered data obtained in many studies for millions of people, and the article has mind-numbing detail on statistical analysis of these studies. Just to cut to the chase, I though it would be interesting to show their final summary and graphic.

The maps displayed show the geographical concentrations of the personality clusters across the United States. What is especially striking is that each of the personality clusters formed a distinctive geographical pattern. Cluster 1 (Friendly & Conventional) comprises states predominantly in the north central Great Plains and in the South. States in the Mountain, Pacific Coast, Mid-Atlantic, and New England regions were the least similar to this particular cluster. States predominantly in the West and some along the Eastern Seaboard were prototypical of Cluster 2 (Relaxed & Creative), whereas most of the states in the Midwest, Great Plains, and Gulf Coast were most different from this cluster. Finally, states in New England and the Middle Atlantic were prototypical of Cluster 3 (Temperamental & Uninhibited), whereas states in the Southeast, Great Plains, and Mountain region were not members of this cluster.

Imaging the the updating of true and false memories.

When we recall, or reactivate a memory, we render it susceptible to alterations such as incorporating relevant new information, so that it might be then stored again in an altered form. Schacter and collaborators at Harvard show show more of what is going on in our brains as reactivation-induced updating both enhances and distorts memory. This process has important implications for understanding the unreliability of eyewitness memories. Here is their abstract:

We remember a considerable number of personal experiences because we are frequently reminded of them, a process known as memory reactivation. Although memory reactivation helps to stabilize and update memories, reactivation may also introduce distortions if novel information becomes incorporated with memory. Here we used functional magnetic resonance imaging (fMRI) to investigate the neural mechanisms mediating reactivation-induced updating in memory for events experienced during a museum tour. During scanning, participants were shown target photographs to reactivate memories from the museum tour followed by a novel lure photograph from an alternate tour. Later, participants were presented with target and lure photographs and asked to determine whether the photographs showed a stop they visited during the tour. We used a subsequent memory analysis to examine neural recruitment during reactivation that was associated with later true and false memories. We predicted that the quality of reactivation, as determined by online ratings of subjective recollection, would increase subsequent true memories but also facilitate incorporation of the lure photograph, thereby increasing subsequent false memories. The fMRI results revealed that the quality of reactivation modulated subsequent true and false memories via recruitment of left posterior parahippocampal, bilateral retrosplenial, and bilateral posterior inferior parietal cortices. However, the timing of neural recruitment and the way in which memories were reactivated contributed to differences in whether memory reactivation led to distortions or not. These data reveal the neural mechanisms recruited during memory reactivation that modify how memories will be subsequently retrieved, supporting the flexible and dynamic aspects of memory.

Naked bodies and mind perception.

Numerous studies have found that viewing people’s bodies, as opposed to their faces, makes us judge them as less intelligent, ambitious, likable, and competent. Kurt Gray, Paul Bloom, and collaborators have published a neat study in The Journal of Personality and Social Psychology that shows further than naked bodies are viewed as having less purposeful agency, but stronger feelings and emotional responses They obtained this result by questioning subjects who were shown pictures of 30 porn stars, with each star represented in an identical pose in two photographs, one naked and the other fully dressed. (Simply revealing more flesh by something as simple as taking off a sweater also could change the way a mind was perceived.)  Here is their abstract:

According to models of objectification, viewing someone as a body induces de-mentalization, stripping away their psychological traits. Here evidence is presented for an alternative account, where a body focus does not diminish the attribution of all mental capacities but, instead, leads perceivers to infer a different kind of mind. Drawing on the distinction in mind perception between agency and experience, it is found that focusing on someone's body reduces perceptions of agency (self-control and action) but increases perceptions of experience (emotion and sensation). These effects were found when comparing targets represented by both revealing versus nonrevealing pictures (Experiments 1, 3, and 4) or by simply directing attention toward physical characteristics (Experiment 2). The effect of a body focus on mind perception also influenced moral intuitions, with those represented as a body seen to be less morally responsible (i.e., lesser moral agents) but more sensitive to harm (i.e., greater moral patients; Experiments 5 and 6). These effects suggest that a body focus does not cause objectification per se but, instead, leads to a redistribution of perceived mind.

Below I include one graphic showing pictures and data from experiment 3, in which subjects were shown naked or clothed people and than asked to rate the person's mental capacities by answering 12 questions with the following beginning: “Compared to the average person, how much is this person capable of X?” In the place of “X” were six agency-related words (self-control, acting morally, planning, communication, memory, and thought) and six experience-related words (feeling pain, feeling pleasure, feeling desire, feeling fear, feeling rage, feeling joy).

Pictures and data from Experiment 3. Ratings of agency and experience for clothed and naked portraits. Error bars are ±1 SE. From XXX: 30 Porn-Star Portraits, by T. Greenfield-Sanders and G. Vidal, 2004, pp. 14, 15, 18–21, 30, 31, 44, 45, 80–85, 92, 93, 102, 103.

Unconscious, not conscious, attitudes predict relationship success.

There has been some recent criticism of 'priming" experiments, in which subliminal presentation, particularly of emotional, stimuli is said to influence the outcome of a decision (see my Nov. 12 post). This is not to be confused with unconscious emotional attitudes, which indeed can be a variance with consciously expressed opinions. McNulty et al. do a nice demonstration of this effect, in showing that 'gut feelings' (implicit attitudes) are a better predictor of success in a marriage than explicit attitudes. They measured explicit and implicit attitudes of newlywed couples toward one another twice a year for 4 years. Over time, the implicit or unaware evaluations of the relationship predicted changes of marital satisfaction, whereas the explicit or conscious evaluations did not.

From their introductory explanation:

The explicit measure was an oft-used semantic differential that asked spouses to report the extent to which they would describe their marriage using 15 pairs of opposing adjectives (e.g., “good” versus “bad,” “satisfied” versus “dissatisfied”). The implicit measure was a version of an associative priming task that required spouses to indicate as quickly as possible the valence of positively and negatively valenced words after being exposed to 300-ms primes of photographs of their partner and various control individuals. An index of spouses’ automatic attitudes was formed by subtracting the time it took them to indicate the valence of the positive words from the time it took them to indicate the valence of the negative words. Both attitude indexes were standardized before analyses. Higher scores on both measures indicate more positive attitudes.

Here is the abstract of the article:

For decades, social psychological theories have posited that the automatic processes captured by implicit measures have implications for social outcomes. Yet few studies have demonstrated any long-term implications of automatic processes, and some scholars have begun to question the relevance and even the validity of these theories. At baseline of our longitudinal study, 135 newlywed couples (270 individuals) completed an explicit measure of their conscious attitudes toward their relationship and an implicit measure of their automatic attitudes toward their partner. They then reported their marital satisfaction every 6 months for the next 4 years. We found no correlation between spouses’ automatic and conscious attitudes, which suggests that spouses were unaware of their automatic attitudes. Further, spouses’ automatic attitudes, not their conscious ones, predicted changes in their marital satisfaction, such that spouses with more positive automatic attitudes were less likely to experience declines in marital satisfaction over time.

Digital Passivity

This piece by Jaron Lanier is well worth reading. A few clips:

I fear that 2013 will be remembered as a tragic and dark year in the digital universe, despite the fact that a lot of wonderful advances took place.

It was the year in which tablets became ubiquitous and advanced gadgets like 3-D printers and wearable interfaces emerged as pop phenomena; all great fun. Our gadgets have widened access to our world. We now regularly communicate with people we would not have been aware of before the networked age. We can find information about almost anything, any time.

But 2013 was also the year in which we became aware of the corner we’ve backed ourselves into. We learned — through the leaks of Edward J. Snowden, the former U.S. National Security Agency contractor, and the work of investigative journalists — how much our gadgets and our digital networks are being used to spy on us by ultra-powerful, remote organizations. We are being dissected more than we dissect...I wish I could separate the two big trends of the year in computing — the cool gadgets and the revelations of digital spying — but I cannot.

...tablets do something unforeseen: They enforce a new power structure. Unlike a personal computer, a tablet runs only programs and applications approved by a central commercial authority. You control the data you enter into a PC, while data entered into a tablet is often managed by someone else...Steve Jobs...declared that personal computers were now ‘‘trucks’’ — tools for working-class guys in T-shirts and visors, but not for upwardly mobile cool people. The implication was that upscale consumers would prefer status and leisure to influence or self-determination.

To be free is to have a private zone in which you can be alone with your thoughts and experiments. That is where you differentiate yourself and grow your personal value. When you carry around a smartphone with a GPS and camera and constantly pipe data to a computer owned by a corporation paid by advertisers to manipulate you, you are less free. Not only are you benefiting the corporation and the advertisers, you are also accepting an assault on your free will, bit by bit.

Childhood poverty changes adult brain emotion regulation pathways.

Kim et al. add sobering detail to the story of how the chronic stress experienced by children in poverty correlates with long term change in the emotion regulation pathways of those children when they become adults. Controlling our emotions depends on the ability of portions of our prefrontal cortex to suppress activation of our amygdala's reactivity. Apparently chronic stress in childhood blocks normal development of this inhibition. Here is the authors' statement of the significance of their work:

Childhood poverty has been linked to emotion dysregulation, which is further associated with negative physical and psychological health in adulthood. The current study provides evidence of prospective associations between childhood poverty and adult neural activity during effortful attempts to regulate negative emotion. Adults with lower family income at age 9 exhibited reduced ventrolateral and dorsolateral prefrontal cortex activity and failure to suppress amygdala activation at age 24. Chronic stressor exposure across childhood mediated the relations between family income at age 9 and prefrontal cortex activity. The concurrent adult income, on the other hand, was not associated with neural activity. The information on the developmental timing of poverty effects and neural mechanisms may inform early interventions aimed at reducing health disparities.

Do you use your head or follow your heart?

Fetterman and Robsinon do a piece of work that tries to provide evidence of what we all commonly suppose: that where we physically locate our self (head or heart) predicts aspects of personality such as rationality versus emotionality, interpersonal warmth versus distance, etc. The kind of work derives from the Lakoff and Johnson studies on embodied cognition - how conceptual metaphors guide thought, emotion, and behavior. The experimental subjects were the usual cohort (112 total, 47 female) of college undergraduates seeking psychology laboratory credit, who were asked "Irrespective of what you know about biology, which body part do you more closely associate with your self? (choose one)." A bit more detail is given, but this is apparently how heart and head types were chosen. I'm going to spare you the details of the numbered experiments that are mentioned, and just note the abstract:

The head is thought to be rational and cold, whereas the heart is thought to be emotional and warm. In 8 studies (total N = 725), we pursued the idea that such body metaphors are widely consequential. Study 1 introduced a novel individual difference variable, one asking people to locate the self in the head or the heart. Irrespective of sex differences, head-locators characterized themselves as rational, logical, and interpersonally cold, whereas heart-locators characterized themselves as emotional, feminine, and interpersonally warm (Studies 1–3). Study 4 showed that head-locators were more accurate in answering general knowledge questions and had higher grade point averages, and Study 5 showed that heart-locators were more likely to favor emotional over rational considerations in moral decision making. Study 6 linked self-locations to reactivity phenomena in daily life—for example, heart-locators experienced greater negative emotion on high stressor days. In Study 7, we manipulated attention to the head versus the heart and found that head-pointing facilitated intellectual performance, whereas heart-pointing led to emotional decision making. Study 8 replicated Study 3’s findings with a nearly year-long delay between the self-location and outcome measures. The findings converge on the importance of head–heart metaphors for understanding individual differences in cognition, emotion, and performance.

Homage to idleness.

All of a sudden this past Saturday morning there was a subtle "poof" from somewhere in my now-cyborg body and it just started thinking and writing again, most likely because its preoccupation with pain was decreasing.

I found myself savoring the period of idleness mandated by having both medial knee joints replaced, and so felt a resonance with this opinion piece by Jessica Kerwin Jenkins "Homage to the Idols of Idleness."

Our struggle against the clock is ancient. As far back as the 2nd century B.C., the Roman playwright Plautus lamented, “The gods confound the man who first found out how to distinguish the hours!” as he railed against the city’s central sundial, which served to “cut and hack my days so wretchedly.” Thousands of years later, what would Plautus make of this ringing, dinging world full of productivity apps that hack ever deeper into our days and nights?

Devices that constantly keep us on course, fixed in place and in time — from the GPS to Siri — ruin our ability to get lost, eradicating randomness and its magic in their wake. Perhaps no one knew this better than France’s early-19th century flâneurs, the idle walkers who happily unspooled their days into the unknown, or the flâneurs’ lowbrow American confreres, the tramp poets of the early 20th century, who surrendered to their surroundings with even more conviction than time-bound monks. In the summer of 1912, the poet Vachel Lindsay set off tramping in a corduroy suit, walking and “meditating on the ways of Destiny,” while preaching the “Gospel of Beauty” to everyone he met...

Our worship of time-management denies the courage these aimless wanderers and idlers demonstrated when stepping out of time. They made the crucial tradeoff: reduced output for liberation. When he died, Henry David Thoreau had published only two books, and “Walden,” then out of print, had been only moderately successful. In the Massachusetts woods, he not only sought solitude, but followed an utterly unconventional timetable, hoeing his beans at 5 a.m. and quitting by noon in order to pursue “other affairs,” like befriending squirrels or lounging next to a spring while reading Homer or the Bhagavad Gita. He chose to “live on the stretch” in order to better savor every moment. “I wanted to live deep and suck out all the marrow of life.”

The stupefying modern obsession with productivity denies the whimsy and the freedom that living fully demands. We must dare to relax our grip on time for a day, or even for an hour, throwing clocks, watches and iPhones over the housetops, untethering ourselves solely for the thrill of not knowing what happens next.

Still alive....

...but in no mood to think or write. 4 hours of rehab exercises every day.

Happy Thanksgiving to all!

MindBlog on medical leave.

I'm heading into knee surgery early tomorrow morning, and may not be feeling in shape to continue doing posts for awhile.

The biology of sacred values.

Frank Rose does a nice piece in the NYTimes, pointing to the work of Gregory Berns and others, on brain correlates of why financial incentives are irrelevant when “sacred values” are at stake. (As in the failure of financial incentives offered by the West in getting Iran to give up its “right” to enrich uranium for “peaceful” uses.) Attempts to offer money to get people to alter strongly held beliefs - with issues like gun control, abortion, Israeli or Palestinian rights to the West Bank of the Jordan - result in moral outrage, feelings of contamination, and a need for moral cleansing. Work by Berns and others suggests we have radically different ways of processing ordinary and sacred beliefs. Berns…

...took M.R.I. images of participants’ brains as he asked them to consider changing their personal beliefs in exchange for money. Would they trade their preference for dogs over cats? What about their belief in God? Would they be willing to kill an innocent person?

When participants were questioned about issues of the dog-or-cat variety, their brain scans showed activity in the parietal cortex — a region that’s thought to be involved in making cost-benefit calculations. But when asked about issues on which they declined to make a trade, entirely different parts of the brain were activated — systems that are associated with telling right from wrong and with storing and retrieving rules. The result, Professor Berns observes, could be a new way to gauge sacred values “that is not solely dependent on self-report.”

Are we going to start running international negotiators through an M.R.I. machine to see where they’re processing the issues? [and determine whether or not someone is faking it when they claim sacred values] Highly unlikely. But results like Professor Berns’s might at least disprove the idea, still held by many, that every belief has its price. Given the intensely negative emotions that financial incentives can trigger, this might be a good lesson to learn.

Here is the abstract from the Berns et al work "The price of your soul: neural evidence for the non-utilitarian representation of sacred values" to which the above is referring. It gives a bit more detail on the brain correlates of sacred values:

Sacred values, such as those associated with religious or ethnic identity, underlie many important individual and group decisions in life, and individuals typically resist attempts to trade off their sacred values in exchange for material benefits. Deontological theory suggests that sacred values are processed based on rights and wrongs irrespective of outcomes, while utilitarian theory suggests that they are processed based on costs and benefits of potential outcomes, but which mode of processing an individual naturally uses is unknown. The study of decisions over sacred values is difficult because outcomes cannot typically be realized in a laboratory, and hence little is known about the neural representation and processing of sacred values. We used an experimental paradigm that used integrity as a proxy for sacredness and which paid real money to induce individuals to sell their personal values. Using functional magnetic resonance imaging (fMRI), we found that values that people refused to sell (sacred values) were associated with increased activity in the left temporoparietal junction and ventrolateral prefrontal cortex, regions previously associated with semantic rule retrieval. This suggests that sacred values affect behaviour through the retrieval and processing of deontic rules and not through a utilitarian evaluation of costs and benefits.

Your fitness age - a simple online calculator

Several popular articles have directed attention to recent work by Nes et al., which suggests that answers to seven simple questions can predict fitness age as well as more exhaustive determinations using peak oxygen intake (VO2) measured on a treadmill, HDL and total cholesterol measurents, accurate determination of body mass index, a lengthy life style questionnaire. Several large scale studies have shown that VO2 max correlates with significantly augmented life spans, and indicates 'fitness age.' They found the simple list of questions predicted VO2 max as well as actual treadmill determinations. I tried their online fitness calculator and discounted its determination that my 71 year old body had the fitness age of a 22-year old. Then I noticed the small detail that the calculator asked for waistline measurement in cm., not inches! Entering the waistline correctly gave me a VO2 max of 40 and fitness age of 59, which is a bit more reasonable. Here is their abstract:

PURPOSE: Cardiorespiratory fitness is suggested to be an important marker of cardiovascular risk but is rarely evaluated in health care settings. In the present study, directly measured peak oxygen uptake (V·O 2peak) from a diverse population of 4637 healthy participants were used to develop and cross-validate a new nonexercise regression model of cardiorespiratory fitness for men and women.

METHODS AND RESULTS: Multivariable regression analysis was used to develop a nonexercise model of cardiorespiratory fitness for men and women separately with V·O 2peak as the outcome. In the final models, 2067 men (mean age = 48.8 yr) and 2193 women (mean age = 47.9 yr) were included, respectively. Cross-validation of the models was done by standard data splitting procedures with evaluation of constant error and total error of a model developed on one sample and cross-validated on another sample. Age, waist circumference, leisure time physical activity, and resting HR, successively, were the most potent predictors of V·O 2peak for both men and women. Together, 61% and 56% of variance in V·O 2peak, for men and women, respectively, were explained by the full models. SEE was 5.70 and 5.14 for the models including men and women, respectively.

CONCLUSIONS: The nonexercise regression model developed in the present study was fairly accurate in predicting V·O 2peak in this healthy population of men and women. The model might be generalized to other healthy populations and might be a valid tool for a rough assessment of cardiorespiratory fitness in an outpatient setting.

Making muscle

Several scientific journals are having a robust and quirky sense of humor these days. I have to pass on this take-off on the Charles Atlas comic advertisements used to describe work by Xu et al. in which a factor obtained from culture of zebrafish embryos is used to induce skeletal muscle differentiation in human induced pluripotent stem cells.

Cell description: The cover catroon tells the story, reported in Xu et al., of an induced pluripotent stem cell (iPSC, shown here in a red t-shirt) that cannot make muscle. When a “bully” researcher tries to steal the postdoctoral fellow working with the iPSC, it's back to the lab, where the fellow uses a zebrafish model to discover chemicals that can turn the iPSC into muscle. Facing down the bully, the postdoctoral fellow rides high on his success. This concept was adapted from Charles Atlas comic advertisements related to bodybuilding. Cover artwork by Athens Qin.

More on long-term benefits of early musical training.

White-Schwoch et al. show that older adults who took music lessons at an early age - the type of instrument doesn't matter - can process the sounds of speech faster than those who did not:

Aging results in pervasive declines in nervous system function. In the auditory system, these declines include neural timing delays in response to fast-changing speech elements; this causes older adults to experience difficulty understanding speech, especially in challenging listening environments. These age-related declines are not inevitable, however: older adults with a lifetime of music training do not exhibit neural timing delays. Yet many people play an instrument for a few years without making a lifelong commitment. Here, we examined neural timing in a group of human older adults who had nominal amounts of music training early in life, but who had not played an instrument for decades. We found that a moderate amount (4–14 years) of music training early in life is associated with faster neural timing in response to speech later in life, long after training stopped (>40 years). We suggest that early music training sets the stage for subsequent interactions with sound. These experiences may interact over time to sustain sharpened neural processing in central auditory nuclei well into older age.

Where musical melodies are represented in our brains.

Here is a fascinating piece by Schindler et al. (open access) showing that musical melodies, or ‘gestalts’ are encoded at very early stages of our auditory processing and are constant through changes of key signature and type of instrument playing.

The perception of a melody is invariant to the absolute properties of its constituting notes, but depends on the relation between them—the melody's relative pitch profile. In fact, a melody's “Gestalt” is recognized regardless of the instrument or key used to play it. Pitch processing in general is assumed to occur at the level of the auditory cortex. However, it is unknown whether early auditory regions are able to encode pitch sequences integrated over time (i.e., melodies) and whether the resulting representations are invariant to specific keys. Here, we presented participants different melodies composed of the same 4 harmonic pitches during functional magnetic resonance imaging recordings. Additionally, we played the same melodies transposed in different keys and on different instruments. We found that melodies were invariantly represented by their blood oxygen level–dependent activation patterns in primary and secondary auditory cortices across instruments, and also across keys. Our findings extend common hierarchical models of auditory processing by showing that melodies are encoded independent of absolute pitch and based on their relative pitch profile as early as the primary auditory cortex.

Why some of us can, or can't, disengage from pain.

Kucyi et al.,  note a beneficial effect of mind wandering and increased default mode network activity on pain suppression. Here is the author's state of the significance of their work:

The mind easily wanders away from mundane tasks, but pain is presumed to automatically capture attention. We demonstrate that individuals differ in how often their minds spontaneously wander away from pain and that these differences are associated with the disruptive effect of pain on cognitive performance. Brain–behavior relationships underscore these individual differences. When people’s minds wander away from pain, there are increased activations of the default mode network (DMN) and strong interactions between the DMN and periaqueductal gray (PAG), an opiate-rich region mediating pain suppression. Individuals with greater tendencies to mind wander from pain have stronger anatomical links and dynamic functional communication between PAG and DMN. These findings provide clinically important clues about why some individuals cannot disengage from pain.

The promises of 'priming'

I've done numerous posts noting psychological experiments on the phenomenon of priming, whose practical application is a major component of behavioral economics. Gary Gutting argues that the significance of priming in our real lives, more complex than the controlled parameters of a psychological experiment, may be overblown in claims that priming experiments provide powerful new tools for influencing human behavior. He starts by noting:

The classic priming experiment was one in which college students had been asked to form various sentences from a given set of words. Those in one group were given words that included several associated with older people (like bingo, gray and Florida). Those in a second group were given words with no such associations. After the linguistic exercise, each participant was instructed to leave the building by walking down a hallway. Without letting the participants know what was going on, the experimenters timed their walks down the hall. They found that those in the group given words associated with old people walked significantly slower than those in the other group. The first group had been primed to walk more slowly.

And, after reviewing claims made for the power of priming techniques to alter our behavior, Gutting notes:

...that priming experiments seldom tell us how important priming is in realistic situations. We know that it has striking effects under highly simplified and controlled laboratory conditions, where the subjects are exposed only to the stimuli that the experimenters provide. But it is very difficult to know how significant priming stimuli (thinking about money, large numbers, abstract questions) would be in a real-life, uncontrolled environment, where all sorts of stimuli might be conflicting with one another. Also, there is seldom any reason to think that even a strong priming effect will last very long. As Jonathan Ellis has noted, even Kahneman ignores these points when, after summarizing the walking-like-the-elderly experiment, he says: “Although you surely were not aware of it, reading this paragraph [which contained many words relating to the elderly] primed you as well. If you had needed to stand up to get a glass of water, you would have been slightly slower than usual to rise from your chair . . . ”

These limits are well illustrated by Richard Thaler and Cass Sunstein’s best-selling book, Nudge. The authors begin with excellent discussions of priming and similar experimental results and then put forward numerous public policy proposals, most of them quite sensible, allegedly inspired by these results. But hardly any of their proposals depend on the results of behavioral economics. Their ideas are mostly a matter of common sense or of strategies long practiced in the business world: in giving people options (regarding decisions like retirement plans or organ donations), make the choice you prefer the default option; provide more or less information on a credit card bill depending on whether you want people to pay just the minimum each month; arrange food in a cafeteria or supermarket so the items you want chosen are most accessible. As Benjamin Friedman pointed out in his review of the book, “we don’t need behavioral economics . . . to think such proposals might be helpful.”

Priming experiments remain important sources of information about the details of how our minds work. It’s possible that they might someday yield valuable techniques for modifying real-world behavior. (Here is one promising if very preliminary example.) But for now claims that they have deep philosophical significance or major practical consequences have scant support.