Control over memory retrieval is predicted by heart rate variability.

Here is a fascinating observation from Gillie et al., who find that a physiological marker, heart rate variability, correlates with a person's ability to control unwanted memories. They use a think/no-think (TNT) task to demonstrate this:

In the TNT paradigm, participants learn a list of cue-response word pairs (e.g., “Tape-Radio”). They are then repeatedly presented with the cues studied earlier (e.g., “Tape”). In the think trials, they are asked to think of the response word (e.g., “Radio”). In the no-think trials, they are asked to prevent recall of the response word. Thus, in the latter case, participants attempt to intentionally stop the retrieval of a memory when presented with a cue. Successful suppression of a target memory should reduce its accessibility at a later point; therefore, recall for the response words is assessed at the end of the experiment. A recent meta-analysis of studies in which this paradigm has been used showed that, on average, people tend to have significantly lower recall of no-think items than of baseline items (word pairs that were studied in the initial phase but not presented in the experimental phase; Levy & Anderson, 2008). This finding, known as the negative-control effect, is taken to be evidence that people can successfully inhibit retrieval of an unwanted memory and that doing so impairs recall for that particular memory.

Here is their abstract:

Stopping retrieval of unwanted memories has been characterized as a process that requires inhibition. However, little research has examined the relationship between control over memory retrieval and individual differences in inhibitory control. Higher levels of resting heart rate variability (HRV) are associated with greater inhibitory control, as indicated by better performance on a number of cognitive, affective, and motor tasks. Therefore, we tested the hypothesis that higher levels of resting HRV predict enhanced memory inhibition as indexed by performance on the think/no-think task. Efforts to suppress no-think word pairs resulted in impaired recall for those items, as in past studies. Moreover, higher levels of resting HRV were associated with more successful suppression, as indicated by lower recall of the to-be-avoided stimuli relative to baseline stimuli. These findings are among the first to suggest that physiological markers of inhibitory control can be used to index a person’s capacity to control unwanted memories.

Some homilies on wisdom - older and wiser.

Because at ~72 years of age I am becoming more aware of how much time I have left rather than how long I have lived, I enjoyed a recent article by Phyllis Korkki. Here are some clips, edits, and paraphrases from the article:

Wisdom defined as maintaining positive well-being and kindness in the face of challenges is one of the most important qualities one can possess to age successfully.

In a 1970’s study by Vivian Clayton, decision makers asked to characterize a wise person stressed three key components: cognition, reflection and compassion.

Elkhonon Goldberg, a neuroscientist in New York and author of “The Wisdom Paradox,” says that “cognitive templates” develop in the older brain based on pattern recognition, and that these can form the basis for wise behavior and decisions.

…acceptance of aging is necessary for growth, but it’s not a resigned acceptance; it’s an embracing acceptance.

From Ursula Staudinger, a life span psychologist and professor at Columbia University: True personal wisdom involves five elements. They are self-insight; the ability to demonstrate personal growth; self-awareness in terms of your historical era and your family history; understanding that priorities and values, including your own, are not absolute; and an awareness of life’s ambiguities.

Modern definitions of wisdom tend to stress kindness, a reduction in self-centeredness, understanding situations from multiple perspectives, showing tolerance as a result

There’s evidence that people who rank high in neuroticism (tendency to be in a negative state for long periods of time) are unlikely to be wise…They see things in a self-centered and negative way and so they fail to benefit emotionally from experience, even though they may be very intelligent.

Daniel Goleman (author of “Emotional Intelligence”: One aspect of wisdom is having a very wide horizon which doesn’t center on ourselves, or even on our group or organization…an important sign of wisdom is “generativity,” a term used by the psychologist Erik Erikson… Generativity means giving back without needing anything in return…The form of giving back could be creative, social, personal or financial.

,,,there’s a point in life when a fundamental shift occurs, and people start thinking about how much time they have left rather than how long they have lived. Reflecting on the meaning and structure of their lives can help people thrive after the balance shifts and there is much less time left than has gone before.

Fat hurts, and exercise helps, the brain.

Gretchen Reynolds points to work by Erion et al.. showing that in obese mice inflammatory cytokines released by fat tissue enter the brain and cause nerve inflammation in the hippocampus, leading to poor learning and memory skills. Apparently obesity weakens the blood-brain barrier that normally would prevent entry of the inflammatory cytokines. (Adipose tissue in obese humans also is a source of proinflammatory cytokines). The authors found that treadmill training could restore the cognitive deficits and normalize hippocampal synaptic function. The same result could be obtained by simply removing fat tissue through lipectomy. Introduction of excess fat tissue into normal animals caused central inflammation and decay in cognitive and synaptic function. Finally they found that a blocker of the interleukin-1 receptors in the hippocampus protected the hippocampus from inflammation. This work "supports a central role for IL1-mediated neuroinflammation as a mechanism for cognitive deficits in obesity and diabetes." Here is their technical abstract:

Adipose tissue is a known source of proinflammatory cytokines in obese humans and animal models, including the db/db mouse, in which obesity arises as a result of leptin receptor insensitivity. Inflammatory cytokines induce cognitive deficits across numerous conditions, but no studies have determined whether obesity-induced inflammation mediates synaptic dysfunction. To address this question, we used a treadmill training paradigm in which mice were exposed to daily training sessions or an immobile belt, with motivation achieved by delivery of compressed air on noncompliance. Treadmill training prevented hippocampal microgliosis, abolished expression of microglial activation markers, and also blocked the functional sensitization observed in isolated cells after ex vivo exposure to lipopolysaccharide. Reduced microglial reactivity with exercise was associated with reinstatement of hippocampus-dependent memory, reversal of deficits in long-term potentiation, and normalization of hippocampal dendritic spine density. Because treadmill training evokes broad responses not limited to the immune system, we next assessed whether directly manipulating adiposity through lipectomy and fat transplantation influences inflammation, cognition, and synaptic plasticity. Lipectomy prevents and fat transplantation promotes systemic and central inflammation, with associated alterations in cognitive and synaptic function. Levels of interleukin 1β (IL1β) emerged as a correlate of adiposity and cognitive impairment across both the treadmill and lipectomy studies, so we manipulated hippocampal IL1 signaling using intrahippocampal delivery of IL1 receptor antagonist (IL1ra). Intrahippocampal IL1ra prevented synaptic dysfunction, proinflammatory priming, and cognitive impairment. This pattern supports a central role for IL1-mediated neuroinflammation as a mechanism for cognitive deficits in obesity and diabetes.

Several perspectives on rich versus poor.

The latest issue of Psychological Science has several articles reflecting different perspectives on rich and poor people:

An analysis noting that residents of poor nations have a greater sense of meaning in life than residents of wealthy nations:

Using Gallup World Poll data, we examined the role of societal wealth for meaning in life across 132 nations. Although life satisfaction was substantially higher in wealthy nations than in poor nations, meaning in life was higher in poor nations than in wealthy nations. In part, meaning in life was higher in poor nations because people in those nations were more religious. The mediating role of religiosity remained significant after we controlled for potential third variables, such as education, fertility rate, and individualism. As Frankl (1963) stated in Man’s Search for Meaning, it appears that meaning can be attained even under objectively dire living conditions, and religiosity plays an important role in this search.

Observations on distorted perceptions of incomes and income inequality in America:

Three studies examined Americans’ perceptions of incomes and income inequality using a variety of criterion measures. Contrary to recent findings indicating that Americans underestimate wealth inequality, we found that Americans not only overestimated the rise of income inequality over time, but also underestimated average incomes. Thus, economic conditions in America are more favorable than people seem to realize. Furthermore, ideological differences emerged in two of these studies, such that political liberals overestimated the rise of inequality more than political conservatives. Implications of these findings for public policy debates and ideological disagreements are discussed.

And, an examination of cognitive and behavioral implication of self-affirmation among the poor:

The poor are universally stigmatized. The stigma of poverty includes being perceived as incompetent and feeling shunned and disrespected. It can lead to cognitive distancing, diminish cognitive performance, and cause the poor to forego beneficial programs. In the present research, we examined how self-affirmation can mitigate the stigma of poverty through randomized field experiments involving low-income individuals at an inner-city soup kitchen. Because of low literacy levels, we used an oral rather than written affirmation procedure, in which participants verbally described a personal experience that made them feel successful or proud. Compared with nonaffirmed participants, affirmed individuals exhibited better executive control, higher fluid intelligence, and a greater willingness to avail themselves of benefits programs. The effects were not driven by elevated positive mood, and the same intervention did not affect the performance of wealthy participants. The findings suggest that self-affirmation can improve the cognitive performance and decisions of the poor, and it may have important policy implications.

A technique for enhancing error awareness in older age.

Harty et al. note yet another salutary effect of transcranial direct current stimulation. A small voltage applied across the right dorsolateral prefrontal cortex enhances error awareness (by 10-12%) in older people. Their studies were done on 106 healthy oder adults 65-86 years of were recruited for four separate experiments. They used.

...a Go/No-go response inhibition task in which subjects are presented with a serial stream of single-color words, with congruency between the semantic meaning of the word and its font color manipulated across trials. Subjects were trained to respond with a single-speeded left mouse button press in situations where the meaning of the word and the font color in which it was presented were congruent (Go trial) and to withhold this response when either of two different scenarios arose: (1) when the word presented on the current trial was the same as that presented on the preceding trial (Repeat No-go trial), and (2) when the meaning of the word and its font color did not match (Stroop No-go trial). In the event of a commission error (failure to withhold to either of these No-go trials), subjects were trained to signal their “awareness” by making a speeded right mouse button press... Stimulation was delivered by a battery-driven DC Brain Stimulator Plus (NeuroConn), through a pair of 35 cm2 saline-soaked sponge electrodes. Current strength was 1 mA in all experiments. This produced current densities of 0.028 mA/cm2 at the skin surface of the scalp...In all four experiments, subjects underwent both Real and Sham tDCS in a single-blind, crossover manner.

Their abstract:

The ability to detect errors during cognitive performance is compromised in older age and in a range of clinical populations. This study was designed to assess the effects of transcranial direct current stimulation (tDCS) on error awareness in healthy older human adults. tDCS was applied over DLPFC while subjects performed a computerized test of error awareness. The influence of current polarity (anodal vs cathodal) and electrode location (left vs right hemisphere) was tested in a series of separate single-blind, Sham-controlled crossover trials, each including 24 healthy older adults (age 65–86 years). Anodal tDCS over right DLPFC was associated with a significant increase in the proportion of performance errors that were consciously detected, and this result was recapitulated in a separate replication experiment. No such improvements were observed when the homologous contralateral area was stimulated. The present study provides novel evidence for a causal role of right DLPFC regions in subserving error awareness and marks an important step toward developing tDCS as a tool for remediating the performance-monitoring deficits that afflict a broad range of populations.

Time, Money, and Morality

Gino and Mogilner note "It seems that a day does not go by without some unethical behavior by a politician, movie star, professional athlete, or high-ranking executive making the headlines. Although less sensational, revelations of cheating have also crept into the sciences, and continue to show up in classrooms, businesses, and marriages."

They proceed to reflect on unethical behavior in people who also strive to maintain a positive self-concept, with morality being central to peoples' self-image. They:

...focus on two triggers that may influence self-reflection and are ubiquitous enough in the environment to have a chance at instigating a widespread effect on unethical behavior: money and time...We specifically predicted that priming people to think about time, rather than money, would lead them to behave more ethically by encouraging them to reflect on who they are and making them more conscious of how they conduct themselves so as to maintain a positive self-image. We tested this hypothesis across four experiments in which we primed participants to think about time or money and observed their tendencies to cheat for monetary or personal gain.

In a first experiment they primed participants with money, time, or neither and then completed a numbers game in which they had the opportunity to cheat by overstating their performance, thereby taking unearned money. Participants primed in the money condition were more likely to cheat.

The second experiment used the numbers game with time or money primes but half the participants were told “This game is an intelligence test that is designed to assess your likelihood to be successful in the future.” and the other half told “This game is a personality test that is designed to assess what type of person you are.” As in the first experiment, participants threw their actual matrix work sheets into a recycle bin, so that they believed they could overreport their performance (i.e., cheat) without getting caught. "In actuality, as in Experiment 1, we were able to match participants’ work sheets with the collection slips on which they reported their performance." The result: "when the game was framed as an intelligence test did thinking about money lead to greater cheating than thinking about time. When the game was framed as a personality test, there was no difference in cheating between the money and time conditions.

A third experiment manipulated self-reflection with a mirror to find that when self-reflection was triggered through the use of a mirror, participants primed with money behaved the same way as those primed with time.

The fourth experiment suggested that "priming time reduces cheating by increasing self-reflection, and priming money increases cheating by lowering self-reflection. By measuring self-reflection directly through self-reports, this experiment provided further evidence for the hypothesized role of self-reflection as the psychological mechanism linking time, money, and morality."

Here is the abstract of the article:

Money, a resource that absorbs much daily attention, seems to be involved in much unethical behavior, which suggests that money itself may corrupt. This research examined a way to offset such potentially deleterious effects—by focusing on time, a resource that tends to receive less attention than money but is equally ubiquitous in daily life. Across four experiments, we examined whether shifting focus onto time can salvage individuals’ ethicality. We found that implicitly activating the construct of time, rather than money, leads individuals to behave more ethically by cheating less. We further found that priming time reduces cheating by making people reflect on who they are. Implications for the use of time primes in discouraging dishonesty are discussed.

Default mode network: the seat of literary creativity?

Wise et al. offer an article with the title of this post in Trends in Cognitive Sciences that comments on the brain areas that consistently become active in different subjects when spoken and written versions of a narrative are presented. They found

...a distribution of correlated activity in the midline posterior cortex and bilateral posterior inferior parietal cortex. This forms the posterior part of the so-called default mode network (DMN; Figure 1), a system classically associated with the introspective mind. It has been observed before, in another meta-analysis of language studies, one that set out to reveal the semantic system [ref]. The authors of that review, and others since (ref), have discussed how memories, semantic and personal, emotions, theory of mind, and no doubt many other mental functions are linked through the DMN. This would suggest that overlapping components of the DMN are functionally interconnected with many separate brain systems, including those for language and semantics, and indeed this is turning out to be the case (refs).

Spot the literary network: the default mode network (DMN) viewed from different angles (colors are intended for illustrative purposes only; data from [ref]). The medial posterior cingulate (PCC) and inferior posterior parietal components (IPP) were implicated in linguistic processing by Regev et al. [ref], but we suggest that due to the widespread connectivity of the DMN, these regions are related to higher order ‘literary’ processing.

Optimism correlates with poor results

Richtel points to work by Sevincer et al. that makes the counter-intuitive observation that optimistic language in newspaper articles and presidential addresses is a predictor of poor economic performance. This actually is consonant with research that has shown that fantasies not tempered by realistic assessment of challenges are less likely to yield results. (People who fantasize about the success of their with control program are less likely to loose pounds). Perhaps people who fantasize an imaged outcome imagine that obtaining it will be easy, and thus work less hard. More sober assessment yields better results.

Previous research has shown that positive thinking, in the form of fantasies about an idealized future, predicts low effort and poor performance. In the studies reported here, we used computerized content analysis of historical documents to investigate the relation between positive thinking about the future and economic development. During the financial crisis from 2007 to 2009, the more weekly newspaper articles in the economy page of USA Today contained positive thinking about the future, the more the Dow Jones Industrial Average declined in the subsequent week and 1 month later. In addition, between the New Deal era and the present time, the more presidential inaugural addresses contained positive thinking about the future, the more the gross domestic product and the employment rate declined in the presidents’ subsequent tenures. These counterintuitive findings may help reveal the psychological processes that contribute to an economic crisis.

Dangerous behaviors and the corporate consumption complex.

Mark Bittman points to Nicholas Freudenberg's new book,  a right-on exposition and summary of

...“the corporate consumption complex,” an alliance of corporations, banks, marketers and others that essentially promote and benefit from unhealthy lifestyles... it’s unlikely there’s a cabal that sits down and asks, “How can we kill more kids tomorrow?” But Freudenberg details how six industries — food and beverage, tobacco, alcohol, firearms, pharmaceutical and automotive — use pretty much the same playbook to defend the sales of health-threatening products. This playbook, largely developed by the tobacco industry, disregards human health and poses greater threats to our existence than any communicable disease you can name...All of these industries work hard to defend our “right” — to smoke, feed our children junk, carry handguns and so on — as matters of choice, freedom and responsibility. Their unified line is that anything that restricts those “rights” is un-American...Yet each industry, as it (mostly) legally can, designs products that are difficult to resist and sometimes addictive... The food industry has created combinations that most appeal to our brains’ instinctual and learned responses.

...we need to be asking not “Do junk food companies have the right to market to children?” but “Do children have the right to a healthy diet?” (In Mexico, the second question has been answered positively. Shamefully, we have yet to take that step.) The question is not only, “Do we have a right to bear arms?” but also “Do we have the right to be safe in our streets and schools?” In short, says Freudenberg: “The right to be healthy trumps the right of corporations to promote choices that lead to premature death and preventable illnesses. Protecting public health is a fundamental government responsibility; a decent society should not allow food companies to convince children to buy food that’s bad for them or to encourage a lifetime of unhealthy eating.”

More on building brains with video games

Nick Bilton does a brief piece on how trying to win various kinds of video games enhances subsequent performance on real world attention and memory tests.

Daphné Bavelier, a neuroscientist with the University of Rochester, found that people who play first-person shooter video games for two weeks can improve visual attention, mental reasoning and decision-making skills. A 2007 study by Iowa State University psychologists compared surgeons who played video games to those who didn’t and found that, during laparoscopic surgeries, the gamers were 27 percent faster and made 37 percent fewer mistakes than nongamers. And decades of research around Tetris has shown that playing it for extended periods may increase memory and cognitive skills.

....the goal is to figure out what makes a game addictive on a neurological level, then to couple this with brain research showing how play can improve the mind...imagine five years from now that you go to the doctor with a problem and he prescribes an F.D.A.-approved video game for you to download and play for two weeks.

Want to remember something? Have some coffee!

Here is the brief abstract from Borota et al., followed by a graphic summary of the results offered by Favila and Kuhl:

It is currently not known whether caffeine has an enhancing effect on long-term memory in humans. We used post-study caffeine administration to test its effect on memory consolidation using a behavioral discrimination task. Caffeine enhanced performance 24 h after administration according to an inverted U-shaped dose-response curve; this effect was specific to consolidation and not retrieval. We conclude that caffeine enhanced consolidation of long-term memories in humans.

Figure: Effect of post-encoding caffeine on memory. On day 1, subjects viewed a series of images of everyday objects and made a judgment about whether each image was likely to be found indoors or outdoors. Immediately after completing this task, they took either caffeine or placebo. Measured caffeine levels fully returned to baseline by the next day. On day 2, subjects were given a surprise memory test. Subjects viewed a series of images and decided whether each image was new (not seen on day 1), old (identical to one of the images from day 1) or similar (a different exemplar of one of the images seen on day 1). The probability of correctly labeling similar images as similar (instead of old) was reflected by a lure discrimination index that corrected for potential response bias. Subjects who received 200 or 300 mg of caffeine after the study period on day 1 showed enhanced lure discrimination on day 2 compared with subjects who received placebo. At 100 mg, caffeine did not enhance test performance, nor did caffeine administered just before the memory test (not shown).

Cognitive aging - a dark side to environmental support?

Lindenberger and Mayr make some very interesting points on the consequences of shifting during aging from self initiation to environmental support in performing tasks. This hits me right between the eyes, as I have been noticing lately how much more likely I am to be working on tasks that are generated by, or reactive to, to my immediate physical, social, financial environment than on projects (like generating music and writing) that I initiate and stay focused on. The Lindenberger and Mayr paper (available to motivated readers who email me) reviews a number of studies beyond the original work on memory by Craik, studies that generalize the effects of self initiated versus environmental support to other cognitive areas such as visual and auditory control. Across processing stages and modalities, older adults are more likely to be guided by external cues than younger adults are. Here I pass on summary points, abstract, and a clip from the discussion.

• Perceptual salience rather than attentional focus governs stimulus processing in old age.
• Older adults rely more on environmental prompts for action than younger adults do.
• Environmental support helps older adults to perform but results in loss of internal control.
• The structure of the environment matters, especially for older adults.

It has been known for some time that memory deficits among older adults increase when self-initiated processing is required and decrease when the environment provides task-appropriate cues. We propose that this observation is not confined to memory but can be subsumed under a more general developmental trend. In perception, learning or memory, and action management, older adults often rely more on external information than younger adults do, probably both as a direct reflection and indirect adaptation to difficulties in internally triggering and maintaining cognitive representations. This age-graded shift from internal towards environmental control is often associated with compromised performance. Cognitive aging research and the design of aging-friendly environments can benefit from paying closer attention to the developmental dynamics and implications of this shift.

Environmental support has a bright and a dark side: it helps aging individuals to perform but comes with a loss in internal control. It follows that the environment matters, especially in old age. The initiation and maintenance of internal control are costly, both cognitively and metabolically and these costs appear to increase from early to late adulthood. By the time they have reached old age, individuals have acquired a behavioral repertoire that is likely to match the regularities and affordances of the environments they live in. The tendency of older adults, both automatic and deliberate, to outsource control to the environment may be inefficient at times, but cost-effective in the long run if the cuing structure of the environment corresponds to their goals and needs. Engineers, psychologists, and aging individuals themselves need to keep this in mind as they design and use adaptive technology in the pursuit of successful aging.

A brain basis for musical hallucinations

Kumar et al. report their findings from an unusual opportunity that presented itself when a retired London schoolteacher, Sylvia, reported to her doctors that she increasingly was hearing music, as if it were completely real, in the absence of a source for the music. (People with musical hallucinations usually are psychologically normal — except for the music they are sure someone is playing. ) Sylvia volunteered for a study by Kumar et al. that made use of the fact that real music can sometimes quiet the imaginary music, in effect masking music hallucination. Playing Bach for 30 seconds was used to damp down the hallucinations while the teacher's brain activity was being monitored by MEG (magnetic recordings), and when the real music stopped the teacher reported the strength of hallucinations as they returned. The brain regions becoming more active as hallucinations returned were the same as those activated by listening to real music. From Zimmer’s review of this work, a suggested model for what is happening:

Our brains… generate predictions about what is going to happen next, using past experiences as a guide. When we hear a sound, for example — particularly music — our brains guess at what it is and predict what it will sound like in the next instant. If the prediction is wrong — if we mistook a teakettle for an opera singer — our brains quickly recognize that we are hearing something else and make a new prediction to minimize the error….people with musical hallucinations often have at least some hearing loss. Sylvia, for example, needed hearing aids after getting a viral infection two decades ago.

The model of our brain as a prediction-generating machine

...could explain why some people with hearing loss develop musical hallucinations. With fewer auditory signals entering the brain, their error detection becomes weaker. If the music-processing brain regions make faulty predictions, those predictions only grow stronger until they feel like reality.

This model:

...could explain why real music provides temporary relief for musical hallucinations: the incoming sounds reveal the brain’s prediction errors. And it may also explain why people are prone to hallucinate music, and not other familiar sounds.

Here is the Kumar et al. abstract:

The physiological basis for musical hallucinations (MH) is not understood. One obstacle to understanding has been the lack of a method to manipulate the intensity of hallucination during the course of experiment. Residual inhibition, transient suppression of a phantom percept after the offset of a masking stimulus, has been used in the study of tinnitus. We report here a human subject whose MH were residually inhibited by short periods of music. Magnetoencephalography (MEG) allowed us to examine variation in the underlying oscillatory brain activity in different states. Source-space analysis capable of single-subject inference defined left-lateralised power increases, associated with stronger hallucinations, in the gamma band in left anterior superior temporal gyrus, and in the beta band in motor cortex and posteromedial cortex. The data indicate that these areas form a crucial network in the generation of MH, and are consistent with a model in which MH are generated by persistent reciprocal communication in a predictive coding hierarchy.

The right temperature for a stroking caress

We apparently have sensory nerves in our skin that are exquisitely tuned for human hedonic, affiliative contact. From Ackerley et al.:

Human C-tactile (CT) afferents respond vigorously to gentle skin stroking and have gained attention for their importance in social touch. Pharmacogenetic activation of the mouse CT equivalent has positively reinforcing, anxiolytic effects, suggesting a role in grooming and affiliative behavior. We recorded from single CT axons in human participants, using the technique of microneurography, and stimulated a unit's receptive field using a novel, computer-controlled moving probe, which stroked the skin of the forearm over five velocities (0.3, 1, 3, 10, and 30 cm s−1) at three temperatures (cool, 18°C; neutral, 32°C; warm, 42°C). We show that CTs are unique among mechanoreceptive afferents: they discharged preferentially to slowly moving stimuli at a neutral (typical skin) temperature, rather than at the cooler or warmer stimulus temperatures. In contrast, myelinated hair mechanoreceptive afferents proportionally increased their firing frequency with stroking velocity and showed no temperature modulation. Furthermore, the CT firing frequency correlated with hedonic ratings to the same mechano-thermal stimulus only at the neutral stimulus temperature, where the stimuli were felt as pleasant at higher firing rates. We conclude that CT afferents are tuned to respond to tactile stimuli with the specific characteristics of a gentle caress delivered at typical skin temperature. This provides a peripheral mechanism for signaling pleasant skin-to-skin contact in humans, which promotes interpersonal touch and affiliative behavior.

Passing ADHD from one generation to the next.

Prenatal and early postnatal exposure of the developing brain to nicotine (PNE) is a major risk factor for inducing attention deficit hyperactivity disorder (ADHD). Children born to mothers who smoke cigarettes before, during, or immediately after pregnancy have a twofold higher risk of developing ADHD. Zhu et al. show that hyperactivity and attention deficits induced by putting nicotine in the drinking water of pregnant mice is transmitted from one generation to the next via the maternal but not the paternal line of descent. The authors note:

A plausible mechanism for the transgenerational transmission of the PNE-induced brain and behavioral changes is heritable epigenetic modifications of the germ cell genome. Nicotine is known to produce DNA methylation in a number of genes, including the gene coding for monoamine oxidase, a key enzyme in the metabolism of dopamine and other monoamines.

Restoring vision to blind mice (and humans with RP or AMD?) with a photoswitch.

Age-related macular degeneration (AMD) and retinitis pigmentosa (RP) affect millions of people around the world and in their advanced stages lead to blindness. Studies in mouse models of these diseases have shown some promise in restoring vision but are either invasive (i.e., implantation of electronic chips) or irreversible (i.e., transplantation of photoreceptor progenitors or viral expression of optogenetic tools). Tochitsky et al. (click on the link to see the authors' fancy PR video of the work) have now performed introcular injection of a synthetic small molecule called DENAQ which is a red-shifted K+ channel photoswitch that exhibits trans to cis photoisomerization with visible light (450–550 nm) and relaxes rapidly to the trans configuration in the dark A single injection photosensitizes blind retinas with no photoreceptors to daylight intensity white light for a period of days with no toxicity. It restores light-elicited behavior and enables visual learning in blind mice. It is a prime drug candidate for vision restoration in patients with end-stage RP and AMD.

Figure of DENAQ from Mourot et al., ACS Chem. Neurosci., 2011, 2 (9), pp 536–543AMD.

Predicting risky choices from brain activity patterns

Helfinstein et al. find some predictive neural correlates of avoiding versus taking risks. Even course global patterns of brain activity reflect enhanced activity when preparing to avoid a risk, suggesting that risk taking may reflect a failure of control systems necessary to initiate a safe choice. It is changes in regions related to risk aversion that most reliably predict whether a subject will make a risky or safe choice. They

...used the Balloon Analog Risk Task (BART), in which subjects receive points as they pump up balloons but risk losing those points should the balloon explode before they choose to stop pumping and “cash out.” Each pump opportunity is a risky decision, where subjects must choose whether to pump again to gain more points or to cash out to secure those points already accrued. The structure of the task, where subjects make sequential risky choices with feedback, is common to many real-world risk-taking situations and matches both the economic and lay definition of risk, in that each successive pump opportunity for a given balloon has both greater variance in possible outcomes and increased exposure to loss. Performance on this task has also been shown, in numerous behavioral studies, to relate to self-reported sensation seeking and to naturalistic risk-taking behaviors, such as smoking, drug use, sexual risk-taking, and unsafe driving behaviors. Because performance on this task consistently correlates with naturalistic risk-taking behaviors, the cognitive processes at work during the task are likely to be comparable to those used during real-world risky decision making.

Here is their abstract:

Previous research has implicated a large network of brain regions in the processing of risk during decision making. However, it has not yet been determined if activity in these regions is predictive of choices on future risky decisions. Here, we examined functional MRI data from a large sample of healthy subjects performing a naturalistic risk-taking task and used a classification analysis approach to predict whether individuals would choose risky or safe options on upcoming trials. We were able to predict choice category successfully in 71.8% of cases. Searchlight analysis revealed a network of brain regions where activity patterns were reliably predictive of subsequent risk-taking behavior, including a number of regions known to play a role in control processes. Searchlights with significant predictive accuracy were primarily located in regions more active when preparing to avoid a risk than when preparing to engage in one, suggesting that risk taking may be due, in part, to a failure of the control systems necessary to initiate a safe choice. Additional analyses revealed that subject choice can be successfully predicted with minimal decrements in accuracy using highly condensed data, suggesting that information relevant for risky choice behavior is encoded in coarse global patterns of activation as well as within highly local activation within searchlights.

Senior Coolness

Swiss researchers Zimmermann and Grebe describe the outcome of analysis of in-depth interviews in German with 65 people aged 77 to 101, which runs counter to the narrative of very old age which tends to focus on deterioration, dementia and burden. Their subjects seem to rise above their problems with a kind of emotional nonchalance, take pleasure in the things they still can do, and choose not do dwell on issues of pain and other problem they can do little about. Here are the highlights and abstract from their article. The article cites many examples from their interviews to make their case (motivated readers can obtain a PDF of the article by emailing me).

Highlights

• Public perceptions of old age (80 +) focus largely on deficiency and loss.
• By contrast, elderly people (80 +) report ways in which they are able to live well.
• Living well in old age can be associated with the capacity to “keep cool”.
• This “senior coolness” renders personal and societal problems manageable.

Abstract

With demographic change becoming an ever more pressing issue in Germany, old age (80 +) is currently talked about above all in terms of being a problem. In mainstream discourse on the situation of the oldest old an interpretive framework has emerged that effectively rules out the possibility of people living positively and well in old age. With regard to both individual (personal) and collective (societal) spheres, negative images of old age dominate public debate. This is the starting point for an interdisciplinary research project designed to look at the ways in which people manage to “live well in old age in the face of vulnerability and finitude” — in express contrast to dominant negative perspectives. Based on the results of this project, the present article addresses an attitudinal and behavioral mode which we have coined “senior coolness”. Coolness here is understood as both a socio-cultural resource and an individualized habitus of everyday living. By providing an effective strategy of self-assertion, this ability can, as we show, be just as important for elderly people as for anyone else. “Senior coolness” is discussed, finally, as a phenomenon that testifies to the ways elderly people retain a positive outlook on life — especially in the face of difficult circumstances and powerful socio-cultural pressures.

In a similar vein, I would recommend reading New Yorker writer Roger Angell's article "This Old Man" about his life in the nineties.

Mindfulness and corporate America’s bottom line.

New Republic senior editor Evgeny Morozov writes a piece called “The Mindfulness Racket”. (I have been working on a brain/mind web lecture on the mindfulnesness / attentional / default / upstairs / downstairs themes, but the deluge of articles in these area is beginning to make me feel like I'm carrying coals to Newcastle.) Some edited clips from Morozov's article:

Mindfulness on the cover of Time magazine...Huffington publications’ stress-tracking app named “GPS for the Soul”…”digital sabbath”…”digital detox”…In essence, we are being urged to unplug-for an hour, a day, a week - so that we can resume our usual activities with even more vigor upon returning to the land of distraction..In our maddeningly complex world, where everything is in flux and defies comprehension, the only reasonable attitude is to renounce any efforts at control and adopt a Zen-like attitude of non-domination.

Huffington hopes that the pursuit of mindfulness can finally reconcile spirituality and capitalism…”So yes, I do want to talk about maximizing profits and beating expectations - by emphasizing the notion that what’s good for us as individuals is also good for corporate America’s bottom line”…

But couldn’t the “disconnectionists”…pursue an agenda a tad more radical than “digital detoxification”? Alexis Madrigal of The Atlantic complains “Individuals unplugging is not actually an answer to the biggest technological problems of our time just as any individual’s local, organic dietary habits don’t solve global agriculture’s issues.”

…why we disconnect matters: We can continue in today’s mode of treating disconnection as a way to recharge and regain productivity, or we can view it as a way to sabotage the addiction tactics of the acceleration distraction complex that is Silicon Valley. The former approach is reactionary but the latter can lead to emancipation, especially if such acts of refusal give rise to genuine social movements that will make problems of time and attention part of their political agendas - and not just the subject of hand-wringing by the Davos-based spirituality brigades…. We must be mindful of all this mindfulness.

Meditation and brain imaging of two kinds of love.

Judson Brewer and collaborators perform fMRI scans of experienced practitioners of loving kindness meditation, which fosters feelings of selfless love for others. Their abstract (below) notes their observations (but doesn't emphasize one of their more interesting findings: that the tranquility of selfless love without expectation of reward lowers activation of the areas activated by romantic love - which are the same reward areas activated by cocaine.)

Loving kindness is a form of meditation involving directed well-wishing, typically supported by the silent repetition of phrases such as “may all beings be happy,” to foster a feeling of selfless love. Here we used functional magnetic resonance imaging to assess the neural substrate of loving kindness meditation in experienced meditators and novices. We first assessed group differences in blood oxygen level-dependent (BOLD) signal during loving kindness meditation. We next used a relatively novel approach, the intrinsic connectivity distribution of functional connectivity, to identify regions that differ in intrinsic connectivity between groups, and then used a data-driven approach to seed-based connectivity analysis to identify which connections differ between groups. Our findings suggest group differences in brain regions involved in self-related processing and mind wandering, emotional processing, inner speech, and memory. Meditators showed overall reduced BOLD signal and intrinsic connectivity during loving kindness as compared to novices, more specifically in the posterior cingulate cortex/precuneus (PCC/PCu), a finding that is consistent with our prior work and other recent neuroimaging studies of meditation. Furthermore, meditators showed greater functional connectivity during loving kindness between the PCC/PCu and the left inferior frontal gyrus, whereas novices showed greater functional connectivity during loving kindness between the PCC/PCu and other cortical midline regions of the default mode network, the bilateral posterior insula lobe, and the bilateral parahippocampus/hippocampus. These novel findings suggest that loving kindness meditation involves a present-centered, selfless focus for meditators as compared to novices.

Neural signature of our own-race bias.

Wiese et al. examine the N170 signal (a component of event related potentials, or ERP recorded from electrodes placed on the head, which is maximal over occipito-temporal electrode sites). It has been linked with the structural encoding of faces. They suggest that ethnicity effects in the N170 reflect an early categorization of other-race faces into a social out-group, resulting in less efficient encoding and thus decreased memory.

Participants are more accurate at remembering faces of their own relative to another ethnic group (own-race bias, ORB). This phenomenon has been explained by reduced perceptual expertise, or alternatively, by the categorization of other-race faces into social out-groups and reduced effort to individuate such faces. We examined event-related potential (ERP) correlates of the ORB, testing recognition memory for Asian and Caucasian faces in Caucasian and Asian participants. Both groups demonstrated a significant ORB in recognition memory. ERPs revealed more negative N170 amplitudes for other-race faces in both groups, probably reflecting more effortful structural encoding. Importantly, the ethnicity effect in left-hemispheric N170 during learning correlated significantly with the behavioral ORB. Similarly, in the subsequent N250, both groups demonstrated more negative amplitudes for other-race faces, and during test phases, this effect correlated significantly with the ORB. We suggest that ethnicity effects in the N170 reflect an early categorization of other-race faces into a social out-group, resulting in less efficient encoding and thus decreased memory. Moreover, ethnicity effects in the N250 may represent the “tagging” of other-race faces as perceptually salient, which hampers the recognition of these faces.

Awesome Images

I want to pass on to MindBlog reader two striking galleries of open access images. The first is Science Magazine's Visualization Challenge. One of its striking images is "Cortex in Metallic Pastels":

The second collection shows natural and manmade places with very unusual colors.

The social (and medical) pathology of correlating inner worth with wealth.

A recent piece by Wilkinson and Pickett in the NYTimes deserves notice. They comment on how wealth inequality is not only divisive and socially corrosive, but also damaging to individuals' mental health. They cite their work showing that:

...major and minor mental illnesses were three times as common in societies where there were bigger income differences between rich and poor. In other words, an American is likely to know three times as many people with depression or anxiety problems as someone in Japan or Germany.

Another study

...looking at the 50 American states, discovered that after taking account of age, income and educational differences, depression was more common in states with greater income inequality. Another, which combined data from over 100 surveys in 26 countries, found that schizophrenia was about three times as common in more unequal societies as it was in more equal ones.

Other clips:

...a wide range of mental disorders might originate in a “dominance behavioral system.” This part of our evolved psychological makeup, almost universal in mammals, enables us to recognize and respond to social ranking systems based on hierarchy and power...One of the important effects of wider income differences between rich and poor is to intensify the issues of dominance and subordination, and feelings of superiority and inferiority.

Humans instinctively know how to cooperate and create social ties, but we also know how to engage in status competition — how to be snobs and how to talk ourselves up. We use these alternative social strategies almost every day of our lives, but crucially, inequality shifts the balance between them...It is hard to avoid the conclusion that we become less nice people in more unequal societies. But we are less nice and less happy: Greater inequality redoubles status anxiety, damaging our mental health and distorting our personalities — wherever we are on the social spectrum.

The article doesn't mention the physical effects that are another major consequence of inequality. Feeling inferior correlates with feeling more helpless than powerful, and hundreds of studies have shown that feelings of helplessness lead to increased disease, lowered immune function, increased anxiety, etc. (enter 'helplessness' in the search box in the left column to see Mindblog posts on this topic.)

Our pupil dilation reflects decision related choice.

Pupil size is known to be increased by effortful decisions. The current supposition is that decision-related pupil dilation tracks the activity of neuromodulatory systems of the brainstem—in particular, the noradrenergic locus coeruleus and, possibly the cholinergic basal forebrain systems. These neuromodulatory systems activate briefly during perceptual decisions such as visual target detection.

de Gee et al. now provide evidence that pupil dilation reflects not the termination of the decision process but rather events during the course of decision formation. The amplitude of pupil dilation is bigger during decision formation for yes than for no choices, and it is strongest in conservative subjects choosing yes against their bias. Imagine what advertisers or merchandizers training cameras on their customers might be able to do with this!

A number of studies have shown that pupil size increases transiently during effortful decisions. These decision-related changes in pupil size are mediated by central neuromodulatory systems, which also influence the internal state of brain regions engaged in decision making. It has been proposed that pupil-linked neuromodulatory systems are activated by the termination of decision processes, and, consequently, that these systems primarily affect the postdecisional brain state. Here, we present pupil results that run contrary to this proposal, suggesting an important intradecisional role. We measured pupil size while subjects formed protracted decisions about the presence or absence (“yes” vs. “no”) of a visual contrast signal embedded in dynamic noise. Linear systems analysis revealed that the pupil was significantly driven by a sustained input throughout the course of the decision formation. This sustained component was larger than the transient component during the final choice (indicated by button press). The overall amplitude of pupil dilation during decision formation was bigger before yes than no choices, irrespective of the physical presence of the target signal. Remarkably, the magnitude of this pupil choice effect (yes > no) reflected the individual criterion: it was strongest in conservative subjects choosing yes against their bias. We conclude that the central neuromodulatory systems controlling pupil size are continuously engaged during decision formation in a way that reveals how the upcoming choice relates to the decision maker’s attitude. Changes in brain state seem to interact with biased decision making in the face of uncertainty.

Reaction time and longevity.

Hagger-Johnson et al. note a correlation between reaction times (doing a button press as quickly as possible after a light flashes on a computer screen) and mortality in 5,145 adults ages 20 to 59 (measured in the late 1980s and early ’90s). The subjects were followed to see how many would be alive after 15 years. After controlling for smoking, drinking, and other factors, the authors found that those with slower reaction times (one standard deviation less than average) were 25 percent more likely to die of any cause, and 36 percent more likely to die of cardiovascular disease, than those with faster reactions. There was no correlation with cancer deaths. The reasons for the statistical correlation is not clear, but the obvious idea is that slower reaction times may reflect brain or nervous system problems that increase morbidity.

Genetic predisposition of our behavioral responses.

Gregory sets the context for a recent article by Skuze et al. on how genes for our oxytocin receptors can influence our social recognition skills:

...the notion that the evolution of our behavioral response is solely shaped by the events themselves is challenged by studies that highlight how interindividual differences in social perception and response to social cues may be determined by underlying genetic predisposition. These studies are establishing that our DNA contains heritable variants that contribute to subtle differences in social cognition. These sequence variants are contained within genes that not only play a role in the relationship that parents may have with their offspring but also how we recognize or react to one another. In PNAS, Skuse et al.investigate the signaling pathways of neuropeptides oxytocin (OT) and arginine-vasopressin (AVP) to identify DNA polymorphisms that might explain interindividual differences in response to social cues. The authors genotyped a series of SNPs from the OT and AVP receptor regions to identify SNPs that account for variation in response to tests of social cognition in autism spectrum disorder (ASD) families.

Here is the Skuze et al. abstract:

The neuropeptides oxytocin and vasopressin are evolutionarily conserved regulators of social perception and behavior. Evidence is building that they are critically involved in the development of social recognition skills within rodent species, primates, and humans. We investigated whether common polymorphisms in the genes encoding the oxytocin and vasopressin 1a receptors influence social memory for faces. Our sample comprised 198 families, from the United Kingdom and Finland, in whom a single child had been diagnosed with high-functioning autism. Previous research has shown that impaired social perception, characteristic of autism, extends to the first-degree relatives of autistic individuals, implying heritable risk. Assessments of face recognition memory, discrimination of facial emotions, and direction of gaze detection were standardized for age (7–60 y) and sex. A common SNP (single nucleotide polymorphism) in the oxytocin receptor (rs237887) was strongly associated with recognition memory in combined probands, parents, and siblings after correction for multiple comparisons. Homozygotes for the ancestral A allele had impairments in the range −0.6 to −1.15 SD scores, irrespective of their diagnostic status. Our findings imply that a critical role for the oxytocin system in social recognition has been conserved across perceptual boundaries through evolution, from olfaction in rodents to visual memory in humans.

Different cultures, different computation systems

Bender and Beller report that a mixed number system superimposing three binary steps onto a decimal structure was invented long before Leibniz’s description of binary numerals, for easier calculations to measure mixed quantities of yams and other garden products, on the Pacific island of Mangareva. It did not arise on other islands of the Pacific with similar ecologies.

...the mixed counting system in Mangarevan...is unique in that it had three binary steps superposed onto a decimal structure. In showing how these steps affect calculation, our analysis yields important insights for theorizing on numerical cognition: counting systems serve as complex cultural tools for numerical cognition, apparently unwieldy systems may in fact be cognitively advantageous, and such advantageous systems can be—and have been—developed by nonindustrialized societies and in the absence of notational systems. These insights also help to dismiss simple notions of cultural complexity as a homogenous state and emphasize that investigating cultural diversity is not merely an optional extra, but a must.

From their conclusions:

Summarizing our results, it seems clear that superposing a decimal system with binary steps is indeed advantageous, as described by Leibniz because it allows arduous calculations and retrieval of addition facts to be replaced by simple transformations in the binary range. Crucially, these advantages are not vitiated by the downside of longer number representations also anticipated by Leibniz. The decimal basis of the system guarantees that number representations remain relatively compact. The mixed system thus neutralizes the tradeoff associated with base size by combining the benefits of a small base (fewer or no addition facts) with the benefits of a larger base (compact representation). Actually, both of these implications adjust to the constraints on working memory and thereby benefit mental arithmetic: the more compact representation relieves cognitive load in retaining information, and the reduction in addition facts relieves cognitive load in processing. The main cost inflicted by this mixing is an increase in irregularity, which requires additional lexemes and rules and thus affects the ease with which a system is learned and mastered....Apparently, its users favored the benefits of the mixed system over the regularity of the general decimal system, as they developed the mixed system out of the purely decimal system in wide use across Polynesia.

Why electroconvulsive therapy works in mood disorders.

Dukart et al. make the interesting observation that the controversial procedure of electroconvulsive therapy causes changes in gray matter volume in the brain areas that are implicated as abnormal in refractory major depression and manic depression:

There remains much scientific, clinical, and ethical controversy concerning the use of electroconvulsive therapy (ECT) for psychiatric disorders stemming from a lack of information and knowledge about how such treatment might work, given its nonspecific and spatially unfocused nature. The mode of action of ECT has even been ascribed to a “barbaric” form of placebo effect. Here we show differential, highly specific, spatially distributed effects of ECT on regional brain structure in two populations: patients with unipolar or bipolar disorder. Unipolar and bipolar disorders respond differentially to ECT and the associated local brain-volume changes, which occur in areas previously associated with these diseases, correlate with symptom severity and the therapeutic effect. Our unique evidence shows that electrophysical therapeutic effects, although applied generally, take on regional significance through interactions with brain pathophysiology.

Constancy of our social signatures.

Robin Dunbar and collaborators have done an interesting examination of the persistence of how many close contacts we maintain (family and close friends) over time, even as the identities of those who are close to us changes. Dunbar is the guy who is well known for his early work showing a correlation between the brain size of social mammals and the size of their social groups. His line relating brain size to group size put the maximal or optimal size of human groups at about 150 individuals. (Enter 'Dunbar' in the search box to the left to see several MindBlog posts on his work.) Here are some clips from their article.

...It appears that having strong and supportive relationships, characterized by closeness and emotional intensity, is essential for health and well-being in both humans and other primates. At the same time, there is a higher cost to maintaining closer relationships, reflected in the amount of effort required to maintain a relation at the desired level of emotional closeness. Because of this, the number of emotionally intense relationships is typically small. Moreover, it has been suggested that ego networks, the sets of ties individuals (egos) have to their friends and family (alters), may be subject to more general constraints associated with limits on human abilities to interact with large numbers of alters. Although there are obvious constraints on the time available for interactions, additional constraints may also arise through limits on memory capacity or other cognitive abilities.

..it is reasonable to ask whether such mechanisms shape these networks in similar ways under different circumstances, giving rise to some characteristic features that persist over time despite network turnover...We combine detailed, autorecorded data from mobile phone call records with survey data. These were collected during a study that tracked changes in the ego networks of 24 students over 18 mo as they made the transition from school to university or work. These changes in personal circumstances result in a period of flux for the social relationships of the participants, with many alters both leaving and entering their networks. This provides a unique setting for studying network-level structure and its response to major changes in social circumstances.

Our results establish three unique findings: (i) There is a consistent, broad, and robust pattern in the way people allocate their communication across the members of their social network, with a small number of top-ranked, emotionally close alters receiving a disproportionately large fraction of calls; (ii) within this general pattern, there is clear individual-level variation so that each individual has a characteristic social signature depicting his or her particular way of communication allocation; and (iii) this individual social signature remains stable and retains its characteristic shape over time and is only weakly affected by network turnover. Thus, individuals appear to differ in how they allocate their available time to their alters, irrespective of who these alters are. Further, our subsidiary analyses (SI Text) suggest that this finding applies not just to call frequencies, because the frequency of calls to an alter correlates with emotional closeness and frequency of face-to-face interactions.

Here is their summary abstract:

We combine cell phone data with survey responses to show that a person’s social signature, as we call the pattern of their interactions with different friends and family members, is remarkably robust. People focus a high proportion of their communication efforts on a small number of individuals, and this behavior persists even when there are changes in the identity of the individuals involved. Although social signatures vary between individuals, a given individual appears to retain a specific social signature over time. Our results are likely to reflect limitations in the ability of humans to maintain many emotionally close relationships, both because of limited time and because the emotional “capital” that individuals can allocate between family members and friends is finite.

Does music make you smarter?

Since I have done a number of posts on long term changes in the brains of adults who have had extensive music training, I thought I should point at an article by Samuel Mehr in the NYTimes that is essentially relaying the results of a study he and his collaborators published in PLOS ONE. Wanting to evaluate reported associations between children's participation in music classes and better grades, higher SAT scores and elevated cognitive skills,they note that correlations are not causes, and do several short term studies on the cognitive effects of a brief series of music classes, compared to non-musical forms of arts instructions. The bottom line was that in two trials, with 29 and 45 preschoolers randomly assigned to music or visual arts classes, they found no evidence that parent-child music classes improved preschoolers' cognitive skills. These brief interventions, studying a limited number of subjects, would need to be repeated to be confirmed, and in any case cast no light on light whether more continuous and rigorous instruction in musical performance correlates with cognitive or brain anatomical changes. Here is their abstract:

Young children regularly engage in musical activities, but the effects of early music education on children's cognitive development are unknown. While some studies have found associations between musical training in childhood and later nonmusical cognitive outcomes, few randomized controlled trials (RCTs) have been employed to assess causal effects of music lessons on child cognition and no clear pattern of results has emerged. We conducted two RCTs with preschool children investigating the cognitive effects of a brief series of music classes, as compared to a similar but non-musical form of arts instruction (visual arts classes, Experiment 1) or to a no-treatment control (Experiment 2). Consistent with typical preschool arts enrichment programs, parents attended classes with their children, participating in a variety of developmentally appropriate arts activities. After six weeks of class, we assessed children's skills in four distinct cognitive areas in which older arts-trained students have been reported to excel: spatial-navigational reasoning, visual form analysis, numerical discrimination, and receptive vocabulary. We initially found that children from the music class showed greater spatial-navigational ability than did children from the visual arts class, while children from the visual arts class showed greater visual form analysis ability than children from the music class (Experiment 1). However, a partial replication attempt comparing music training to a no-treatment control failed to confirm these findings (Experiment 2), and the combined results of the two experiments were negative: overall, children provided with music classes performed no better than those with visual arts or no classes on any assessment. Our findings underscore the need for replication in RCTs, and suggest caution in interpreting the positive findings from past studies of cognitive effects of music instruction.

When psychotherapy works - what are the brain changes?

The journal Brain and Behavioral Science circulates forthcoming articles for peer commentary before their final publication in the journal. I thought I would pass on the abstract of such an article by Lane et al., who propose that the essential ingredients in therapeutic change include: 1) reactivating old memories; 2) engaging in new emotional experiences that are incorporated into these reactivated memories via the process of reconsolidation; and 3) reinforcing the integrative memory structure by practicing a new way of behaving and experiencing the world in a variety of contexts.

Memory Reconsolidation, Emotional Arousal and the Process of Change in Psychotherapy: New Insights from Brain Science

Richard D. Lane, Lee Ryan, Lynn Nadel, and Leslie Greenberg

Abstract: Since Freud clinicians have understood that disturbing memories contribute to psychopathology and that new emotional experiences contribute to therapeutic change. Yet, controversy remains about what is truly essential to bring about psychotherapeutic change. Mounting evidence from empirical studies suggests that emotional arousal is a key ingredient in therapeutic change in many modalities. In addition, memory seems to play an important role but there is a lack of consensus on the role of understanding what happened in the past in bringing about therapeutic change.

The core idea of this paper is that therapeutic change in a variety of modalities, including behavioral therapy, cognitive-behavioral therapy, emotion-focused and psychodynamic psychotherapy, results from the updating of prior emotional memories through a process of reconsolidation that incorporates new emotional experiences. The authors present an integrative memory model with three interactive components - autobiographical (event) memories, semantic structures, and emotional responses - supported by emerging evidence from cognitive neuroscience on implicit and explicit emotion, implicit and explicit memory, emotion-memory interactions, memory reconsolidation, and the relationship between autobiographical and semantic memory. We propose that the essential ingredients of therapeutic change include: 1) reactivating old memories; 2) engaging in new emotional experiences that are incorporated into these reactivated memories via the process of reconsolidation; and 3) reinforcing the integrative memory structure by practicing a new way of behaving and experiencing the world in a variety of contexts. The implications of this new neurobiologically-grounded synthesis for research, clinical practice and teaching are discussed.

Making Our Brains Younger

I thought I would pass on this link to a brief (15 min) talk I gave to the Feb. 2, 2014, meeting of the Fort Lauderdale Prime Timers group. It discusses brain changes on aging and ways to reverse them. (I also have put a link to the talk in MindBlog's left column, and a photo taken by Kaz Takahashi at one of the few times I was smiling during the presentation.)

MindBlog's most read posts.

I'm doing a review of older MindBlog posts to see what categories collect themselves as potential talks or web-lectures of the sort you see in the left column.  I checked the statistics on what the most read posts have been since MindBlog started up in February of 2006, and thought I would pass that on to readers (click on the graphic to enlarge it). If you want to check out one of the posts, simply type a few words of the title into the search box to your left, and it will be retrieved.

The myth of cognitive decline with aging? Yes and No....

Offering something of an antidote to the drumbeat of articles measuring cognitive declines on again, Ramscar et al. (open source) suggest that changing performance patterns that are typically taken as evidence for (and measures of) cognitive decline arise out of basic principles of learning and emerge naturally in learning models as they acquire more knowledge, with patterns of performance reflect the information-processing costs that must inevitably be incurred as knowledge is acquired. Their arguments seem relevant to lexical tasks such as recalling words, but are not germane to declines in visual or auditory attention and processing speed (usually described as 'cognitive' declines) for which underlying brain structural and functional correlates have been observed. They also do not address the issue of noise, or competition from competing memories, as influencing lexical retrieval tasks. The second abstract below, work of Healey et al., notes this possibility. So, first the Ramscar et al. abstract:

As adults age, their performance on many psychometric tests changes systematically, a finding that is widely taken to reveal that cognitive information-processing capacities decline across adulthood. Contrary to this, we suggest that older adults'; changing performance reflects memory search demands, which escalate as experience grows. A series of simulations show how the performance patterns observed across adulthood emerge naturally in learning models as they acquire knowledge. The simulations correctly identify greater variation in the cognitive performance of older adults, and successfully predict that older adults will show greater sensitivity to fine-grained differences in the properties of test stimuli than younger adults. Our results indicate that older adults'; performance on cognitive tests reflects the predictable consequences of learning on information-processing, and not cognitive decline. We consider the implications of this for our scientific and cultural understanding of aging.

And now the Healey et al. abstract on noise or interference resolution by younger but not older adults:

Resolving interference from competing memories is a critical factor in efficient memory retrieval, and several accounts of cognitive aging suggest that difficulty resolving interference may underlie memory deficits such as those seen in the elderly. Although many researchers have suggested that the ability to suppress competitors is a key factor in resolving interference, the evidence supporting this claim has been the subject of debate. Here, we present a new paradigm and results demonstrating that for younger adults, a single retrieval attempt is sufficient to suppress competitors to below-baseline levels of accessibility even though the competitors are never explicitly presented. The extent to which individual younger adults suppressed competitors predicted their performance on a memory span task. In a second experiment, older adults showed no evidence of suppression, which supports the theory that older adults’ memory deficits are related to impaired suppression.

ADDED NOTE:

After I composed the above post Benedict Carey's mention of the Ramscar et al. article appeared in the NYTimes and became a 'most emailed article' for several days. He makes the same points that I do as a counter to over-interpreting Ramscar et al.'s data.

Most published scientific results are false.

I would highly recommend reading this article by George Johnson, which points in particular to the work of John P. A. Ioannidis, a kind of meta-scientist who researches research, who wrote a 2005 paper pointedly titled “Why Most Published Research Findings Are False.” Here is one clip from the Johnson article:

If one of five competing labs is alone in finding an effect, that result is the one likely to be published. But there is a four in five chance that it is wrong. Papers reporting negative conclusions are more easily ignored...Putting all of this together, Dr. Ioannidis devised a mathematical model supporting the conclusion that most published findings are probably incorrect....the same year he published another blockbuster, examining more than a decade’s worth of highly regarded papers — the effect of a daily aspirin on cardiac disease, for example, or the risks of hormone replacement therapy for older women. He found that a large proportion of the conclusions were undermined or contradicted by later studies.

His work was just the beginning. Concern about the problem has reached the point that the journal Nature has assembled an archive, filled with reports and analyses, called Challenges in Irreproducible Research.. Among them is a paper in which C. Glenn Begley, who is chief scientific officer at TetraLogic Pharmaceuticals, described an experience he had while at Amgen, another drug company. He and his colleagues could not replicate 47 of 53 landmark papers about cancer. Some of the results could not be reproduced even with the help of the original scientists working in their own labs....Given what is at stake, it seems like a moral failing that the titles of the papers were not revealed. That was forbidden, we’re told, by confidentiality agreements imposed by the labs.

Mindfulness has so totally gone mainstream…..

Mindfulness at Davos

Mindfulness - the Time Magazine cover story

Enriched environments enhance adult brain plasticity.

I learned much of my neuroscience at tea time in Hubel and Wiesel's laboratory at Harvard Medical School during my post-doc days in the 1960's, as we discussed their discovery of critical periods during the development of ocular dominance columns in the visual cortex, and the apparent immutability of the adult pathways, once formed. Everything now has changed. We know our brains maintain their ability to make new nerve cells and connections throughout life. Greifzu et. al. add a new chapter to the plasticity story in their recent work showing how important enriched environments are in maintaining a younger brain that has not been locked into place by the increased inhibitory interactions characteristic of adult brains. Specifically, they show that ocular dominance columns can remain plastic in adult mice in enriched, but not ordinary cage, environments, and recover from stroke-induced damage or monocular deprivation.

Experimental animals are usually raised in small, so-called standard cages, depriving them of numerous natural stimuli. We show that raising mice in an enriched environment, allowing enhanced physical, social, and cognitive stimulation, preserved a juvenile brain into adulthood. Enrichment also rejuvenated the visual cortex after extended periods of standard cage rearing and protected adult mice from stroke-induced impairments of cortical plasticity. Because the local inhibitory tone in the visual cortex of adult enriched mice was not only significantly reduced compared with nonenriched animals but at juvenile levels, the plasticity-promoting effect of enrichment is most likely mediated by preserving low juvenile levels of inhibition into adulthood and thereby, extending sensitive phases of enhanced neuronal plasticity into an older age.

How inactivity changes the brain

Here is yet another sobering note for couch potatoes. Lack of exercise (in rats) causes undesirable remodeling of the brain. Gretchen Reynolds points to work by Mischel et al. (open source) showing that inactive versus active rats show changes in the region of the rostral ventrolateral medulla that regulates the sympathetic nervous system, increasing connectivity and reactivity, potentially overstimulating the sympathetic nervous system to constrict blood vessels, increase blood pressure, and thus enhance the possibility of cardiovascular disease. Here is the Mischel et al. abstract and a summary figure:

Increased activity of the sympathetic nervous system is thought to play a role in the development and progression of cardiovascular disease. Recent work has shown that physical inactivity versus activity alters neuronal structure in brain regions associated with cardiovascular regulation. Our physiological studies suggest that neurons in the rostral ventrolateral medulla (RVLM) are more responsive to excitation in sedentary versus physically active animals. We hypothesized that enhanced functional responses in the RVLM may be due, in part, to changes in the structure of RVLM neurons that control sympathetic activity. We used retrograde tracing and immunohistochemistry for tyrosine hydroxylase (TH) to identify bulbospinal catecholaminergic (C1) neurons in sedentary and active rats after chronic voluntary wheel-running exercise. We then digitally reconstructed their cell bodies and dendrites at different rostrocaudal levels. The dendritic arbors of spinally projecting TH neurons from sedentary rats were more branched than those of physically active rats (P < 0.05). In sedentary rats, dendritic branching was greater in more rostral versus more caudal bulbospinal C1 neurons, whereas, in physically active rats, dendritic branching was consistent throughout the RVLM. In contrast, cell body size and the number of primary dendrites did not differ between active and inactive animals. We suggest that these structural changes provide an anatomical underpinning for the functional differences observed in our in vivo studies. These inactivity-related structural and functional changes may enhance the overall sensitivity of RVLM neurons to excitatory stimuli and contribute to an increased risk of cardiovascular disease in sedentary individuals.

Physical inactivity versus activity is associated with functional changes in control of blood pressure by neurons in the rostral ventrolateral medulla (RVLM). The present study shows that putative cardiovascular RVLM neurons have more complex dendrites in inactive versus active rats. This anatomical difference may underpin the functional differences previously reported.

The liberal illusion of uniqueness

Bill Clinton is reported to have complained that getting Democrats to agree on a course of action was like herding cats, while the Republicans didn’t seem to have this problem. Stern et al. do a fascinating nugget of work that shows that conservatives and moderates overestimate the degree to which others conservative and moderates are like them, while those on the left end of the spectrum assume they are more unique among party peers than they actually are. (Recall the inability of the Occupy Wall Street movement in 2011 to achieve consensus on vital issues.) The authors used well-validated methodology for examining truly false consensus and truly false uniqueness effects by developing a procedure in which participants were asked to indicate their beliefs and their preferences for a series of items and then estimate the beliefs and preferences of political in-group members. To test for truly false uniqueness and truly false consensus effects, They compared the extent to which participants perceived that political in-group members shared their beliefs and preferences with the extent to which political in-group members actually shared participants’ beliefs and preferences. From their methods section:

We conducted two studies in which participants reported their beliefs and preferences and estimated the beliefs and preferences of political in-group members who were either fellow participants in the study (Study 1) or members of the general American population (Study 2). This procedure allowed us to examine whether similar patterns of effects would emerge even when participants thought about political in-group members in different contexts. In Study 2, we replicated and extended Study 1 by examining whether the desire to feel unique explains in part ideological differences in estimating similarity to political in-group members. Finally, previous research has shown that individuals perceive more similarity between their own beliefs and those of other individuals (i.e., perceive greater consensus) when the beliefs are socially desirable or personally important. To rule out the possibility that these factors explain ideological differences in perceiving similarity to political in-group members, we measured the perceived social desirability of the items to which participants responded in both studies. In addition, in Study 2, we measured the personal importance of the items to rule out the possibility that this factor would explain ideological differences in perceiving similarity.

Here is their brief abstract.

In two studies, we demonstrated that liberals underestimate their similarity to other liberals (i.e., display truly false uniqueness), whereas moderates and conservatives overestimate their similarity to other moderates and conservatives (i.e., display truly false consensus; Studies 1 and 2). We further demonstrated that a fundamental difference between liberals and conservatives in the motivation to feel unique explains this ideological distinction in the accuracy of estimating similarity (Study 2). Implications of the accuracy of consensus estimates for mobilizing liberal and conservative political movements are discussed.

The Kerfuffle over whether men and women's brains are different.

Nothing kicks up a firestorm in the Neuroscience blogosphere like talk of sex differences in brain architecture. Within days of PNAS's early December 2013 publication of what may be a landmark paper on the differing 'connectomes' (nerve fiber tracts connecting different brain areas) of 428 male and 521 female 8-22 year old humans, a storm of criticism of the work was bouncing around the internet, along with accusations of 'neurosexism'. (see, for example, here, here, here, and here.)

The critics make many points - 1. Men have bigger brains on average than women, possibly conflating results; 2. Maybe men and women move their heads differently while in the MRI machine; 3. The structural differences don't necessarily correlate with behavioral differences, and there are varying results on whether the structural results correlate with cognitive function tests. It is unfortunate that the authors of the study were spouting gender stereotypes...but...it seems to me that the objections are mainly nit-picking, the data are rather compelling on fundamental differences in sexual connectivity that arise from genetic/environmental/cultural factors during brain development. (There is no such thing as 'hard wiring'.):

The results establish that male brains are optimized for intrahemispheric and female brains for interhemispheric communication. The developmental trajectories of males and females separate at a young age, demonstrating wide differences during adolescence and adulthood...The brains of men exhibit a far smaller degree of interconnectedness, both within and across the hemispheres, than do those of women.

I decided to wait for the dust to settle a bit, and let the final publication appear, and sure enough in the same issue there is an essay commentary by Larry Cahill that argues essentially that the politically correct view in brain research has been to assume no significant difference between male and female brain, and to assume results obtained (mainly for male brains) apply also to female brains.  Mouse studies in particular have shown that this is not the case.

...we now know that sex influences—small to medium to large—are extremely widespread on brain function. The validity of the assumption that the sex of subjects cannot powerfully alter, negate, and even reverse findings (hence, conclusions) has been crushed under the weight of evidence proving that it can and regularly does and at every level of investigation down to genes, single neurons, and even ion channels...For neuroscientists cognizant of this striking development, the main challenge now is to better understand the dizzying plethora of sex influences being uncovered. Males and females appear to be two complex mosaics, similar in some respects, mildly to highly different in others

Here is Cahill's summary comment:

A comedian discussing men and women once described the male brain as a bunch of boxes that don’t touch one another and the female brain as a complex ball of interconnected wires. Amusing as the bit was, the analogies may be more apt than he could have known. The findings of Ingahalikar et al. do indeed point to a greater degree of modular function in the physical architecture of the male brain and of interconnectedness in physical architecture of the female brain. Given the size of the study, the consistency of the conclusions across various analytic approaches, and the seeming concordance of key findings with well-established literature addressing brain function, one cannot fairly accuse Ingalhalikar et al. of hyperbole when they claim that their findings “reveal fundamental sex differences in the architecture of the human brain.” Theirs is a landmark paper that should accelerate acceptance of the notion that, for those who want to understand how brains function, sex matters.

And here, finally, is the Ingalhalikar et al. abstract:

Sex differences in human behavior show adaptive complementarity: Males have better motor and spatial abilities, whereas females have superior memory and social cognition skills. Studies also show sex differences in human brains but do not explain this complementarity. In this work, we modeled the structural connectome using diffusion tensor imaging in a sample of 949 youths (aged 8–22 y, 428 males and 521 females) and discovered unique sex differences in brain connectivity during the course of development. Connection-wise statistical analysis, as well as analysis of regional and global network measures, presented a comprehensive description of network characteristics. In all supratentorial regions, males had greater within-hemispheric connectivity, as well as enhanced modularity and transitivity, whereas between-hemispheric connectivity and cross-module participation predominated in females. However, this effect was reversed in the cerebellar connections. Analysis of these changes developmentally demonstrated differences in trajectory between males and females mainly in adolescence and in adulthood. Overall, the results suggest that male brains are structured to facilitate connectivity between perception and coordinated action, whereas female brains are designed to facilitate communication between analytical and intuitive processing modes.

Bodily maps of emotions.

Nummenmaa and collaborators, from several universities in Finland, propose that our emotions are represented in our somatosensory system as culturally universal categorical somatotopic maps.

Emotions are often felt in the body, and somatosensory feedback has been proposed to trigger conscious emotional experiences. Here we reveal maps of bodily sensations associated with different emotions using a unique topographical self-report method. In five experiments, participants (n = 701) were shown two silhouettes of bodies alongside emotional words, stories, movies, or facial expressions. They were asked to color the bodily regions whose activity they felt increasing or decreasing while viewing each stimulus. Different emotions were consistently associated with statistically separable bodily sensation maps across experiments. These maps were concordant across West European and East Asian samples. Statistical classifiers distinguished emotion-specific activation maps accurately, confirming independence of topographies across emotions. We propose that emotions are represented in the somatosensory system as culturally universal categorical somatotopic maps. Perception of these emotion-triggered bodily changes may play a key role in generating consciously felt emotions.

Figure - Bodily topography of basic (Upper) and nonbasic (Lower) emotions associated with words. The body maps show regions whose activation increased (warm colors) or decreased (cool colors) when feeling each emotion.

The morning morality effect.

Here is an interesting tidbit from Kouchaki1 and Smith:

Are people more moral in the morning than in the afternoon? We propose that the normal, unremarkable experiences associated with everyday living can deplete one’s capacity to resist moral temptations. In a series of four experiments, both undergraduate students and a sample of U.S. adults engaged in less unethical behavior (e.g., less lying and cheating) on tasks performed in the morning than on the same tasks performed in the afternoon. This morning morality effect was mediated by decreases in moral awareness and self-control in the afternoon. Furthermore, the effect of time of day on unethical behavior was found to be stronger for people with a lower propensity to morally disengage. These findings highlight a simple yet pervasive factor (i.e., the time of day) that has important implications for moral behavior.