Aging, sleep, and memory.

Events during a day that we think important to remember are held in short term memory storage by an active hippocampus. Then, during deep, non-REM, slow brain wave sleep, enhanced connectivity between the hippocampus and frontal cortex cortex allow transfer of the information to long term storage in frontal and temporal lobes. It is also know that the duration of this deep sleep diminishes as our frontal lobes diminish in size (atrophy) with aging. Mandor et al., in worked pointed to in an article by Benedict Carey, have done an interesting study suggesting that the interaction of these factors represents a neuropatholgical pathway associated with cognitive decline in later life. Here is their abstract:

Aging has independently been associated with regional brain atrophy, reduced slow wave activity (SWA) during non–rapid eye movement (NREM) sleep and impaired long-term retention of episodic memories. However, whether the interaction of these factors represents a neuropatholgical pathway associated with cognitive decline in later life remains unknown. We found that age-related medial prefrontal cortex (mPFC) gray-matter atrophy was associated with reduced NREM SWA in older adults, the extent to which statistically mediated the impairment of overnight sleep–dependent memory retention. Moreover, this memory impairment was further associated with persistent hippocampal activation and reduced task-related hippocampal-prefrontal cortex functional connectivity, potentially representing impoverished hippocampal-neocortical memory transformation. Together, these data support a model in which age-related mPFC atrophy diminishes SWA, the functional consequence of which is impaired long-term memory. Such findings suggest that sleep disruption in the elderly, mediated by structural brain changes, represents a contributing factor to age-related cognitive decline in later life.

Racial essentialism correlates with less domain-general creativity.

Interesting observations from a group at Tel Aviv University:

Individuals who believe that racial groups have fixed underlying essences use stereotypes more than do individuals who believe that racial categories are arbitrary and malleable social-political constructions. Would this essentialist mind-set also lead to less creativity? We suggest that the functional utility derived from essentialism induces a habitual closed-mindedness that transcends the social domain and hampers creativity. Across studies, using both individual difference measures (in a pilot test) and experimental manipulations, we found that an essentialist mind-set is indeed hazardous for creativity, with the relationship mediated by motivated closed-mindedness. These results held across samples of majority cultural-group members (Caucasian Americans, Israelis) and minority-group members (Asian Americans), as well as across different measures of creativity (flexibility, association, insight). Our findings have important implications for understanding the connection between racial intolerance and creativity.

Some details: Participants in the study were primed by reading an article that vividly described fictitious scientific research supporting either racial essentialist or nonessentialist beliefs, respectively. (Work by others had established the effectiveness of these articles in activating racial essentialism or nonessentialism mind-sets). A control group read neither article. Then, in an ostensibly unrelated research project, they measured creativity in the three conditions using the Remote Associates Test (RAT). This task, which assesses participants’ ability to form a new combination that links mentally distant associative elements, requires identifying a single target word that is strongly associated with three distinct stimulus words (e.g., given the words “manners,” “round,” and “tennis,” the correct answer would be “table”). Their experiment suggesting closed-mindedness as the mediator of the essentialism-creativity link used the same priming procedure and assayed insight creativity using the Duncker candle problem, in which participants have to figure out how — using only a candle, a pack of matches, and a box containing tacks — they can attach the candle to a wall so that the candle burns properly without dripping wax on the table or floor. (The correct solution requires the ability to relax preexisting assumptions about functions of the items and use the box of tacks as a candleholder.)

"Chasing Ice" - watching a glacier calving

 I have to pass on this amazing video shared by Wisconsin colleague John Young, showing one of the breakdowns of a glacier that has retreated as much in the past 10 years as in the previous 100 years:

Early musical training - sensitive period in brain white matter plasticity

MindBlog has noted a number of studies that document beneficial effects of early music training on adult brain function. Now Steele and collaborators make observations that may partially explain why musicians such as Yo-Yo Ma, Oscar Peterson, and Pablo Casals, who all began training in early childhood before the age of 7 years, are so highly skilled. The authors examine the bundle of nerve fibers, the corpus callosum, that links our two cerebral hemispheres. Playing a musical instrument requires the coordinated action of the two hands and interhemispheric interactions mediated by the corpus callosum have been shown to play a prominent role in bimanual coordination. They measure the connectivity of this nerve fiber bundle using MRI. Edited from their introduction:

...there may be a sensitive period when early musical training has greater effects on the brain and behavior than training later in life...A sensitive period is defined as a developmental window where experience has long-lasting effects on the brain and behavior ...studies in animals show that exposure or training during specific periods in development can produce enhanced structural and functional plasticity in visual, auditory, and somatosensory regions of the brain...Evidence for sensitive periods in humans comes from studies of second language learning showing that early exposure results in greater proficiency, studies of deaf children showing that receiving cochlear implants earlier results in better language development, and studies of blind persons showing greater neuronal reorganization following early blindness.

Musicians are an excellent model for investigating possible sensitive period effects on brain and behavior, as training often begins early and is quantifiable...Evidence for a possible sensitive period for musical training came from a study showing that the anterior corpus callosum (CC) was larger in musicians than non-musicians, and that the difference was greater for those who began training before the age of 7 years...However, none of these studies controlled for the fact that musicians who begin earlier typically have more training than those who begin later.

Here is their abstract:

Training during a sensitive period in development may have greater effects on brain structure and behavior than training later in life. Musicians are an excellent model for investigating sensitive periods because training starts early and can be quantified. Previous studies suggested that early training might be related to greater amounts of white matter in the corpus callosum, but did not control for length of training or identify behavioral correlates of structural change. The current study compared white-matter organization using diffusion tensor imaging in early- and late-trained musicians matched for years of training and experience. We found that early-trained musicians had greater connectivity in the posterior midbody/isthmus of the corpus callosum and that fractional anisotropy in this region was related to age of onset of training and sensorimotor synchronization performance. We propose that training before the age of 7 years results in changes in white-matter connectivity that may serve as a scaffold upon which ongoing experience can build.

The promise and perils of oxytocin.

Greg Miller summarizes some consequences of recent work showing that oxytocin promotes trust and cooperation, and makes people more attuned to social cues.  It has some not so sweet aspects also.  He mentions a number of the studies I've cited in previous mindblog posts (just enter oxytocin in the search box in the left column to display them):

Now psychiatrists have caught oxytocin fever...Many psychiatric conditions have social symptoms, such as the characteristic lack of empathy in autism, the attachment anxiety of borderline personality disorder, and the paranoia of schizophrenia. Yet no drugs currently approved for psychiatric use directly target social behavior...But as researchers have continued to explore the hormone's effect on human behavior, a darker side has emerged. Oxytocin seems to promote aggression or other antisocial behavior in some circumstances. Its effects also appear to vary depending on a person's genetic makeup and psychological status. And no one knows what long-term oxytocin treatment does to the developing human brain. Disconcertingly, one recent study found that male voles treated for several weeks with oxytocin nasal spray around the time of adolescence later exhibited impaired social bonding with females... thus, there is concern about giving oxytocin to children before more is known about the hormone's developmental effects.

...the more recent oxytocin research in humans has frequently found its way into tabloids. In one of the first eye-catching studies in 2005 students who got oxytocin were more trusting...A torrent of studies followed, suggesting that oxytocin not only increases trust and cooperation, but also boosts social perceptiveness, such as face recognition and the ability to read what's on someone's mind from the look in their eyes.

A number of clinical trials suggest oxytocin causes a modest improvement in children and adults with autism, also in social behavior of psychotic patients, but reservations are raised by the vole studies showing early administration of oxytocin disturbs adult bonding and reproductive behavior, and by human studies showing that while it increases altruistic behavior towards in-group individuals, it increases aggression towards out group people.

How our brains judge risk and effort.

Burke et al. do a nice piece of work showing that the risk of an option for action is encoded by the anterior insula and the effort required for that action is coded in mid-cingulate and supplementary motor area. If there is a need to do so, the frontal pole integrates effort and risk costs through functional coupling with the SMA and insula.

Rewards in real life are rarely received without incurring costs and successful reward harvesting often involves weighing and minimizing different types of costs. In the natural environment, such costs often include the physical effort required to obtain rewards and potential risks attached to them. Costs may also include potential risks. In this study, we applied fMRI to explore the neural coding of physical effort costs as opposed to costs associated with risky rewards. Using an incentive-compatible valuation mechanism, we separately measured the subjective costs associated with effortful and risky options. As expected, subjective costs of options increased with both increasing effort and increasing risk. Despite the similar nature of behavioral discounting of effort and risk, distinct regions of the brain coded these two cost types separately, with anterior insula primarily processing risk costs and midcingulate and supplementary motor area (SMA) processing effort costs. To investigate integration of the two cost types, we also presented participants with options that combined effortful and risky elements. We found that the frontal pole integrates effort and risk costs through functional coupling with the SMA and insula. The degree to which the latter two regions influenced frontal pole activity correlated with participant-specific behavioral sensitivity to effort and risk costs. These data support the notion that, although physical effort costs may appear to be behaviorally similar to other types of costs, such as risk, they are treated separately at the neural level and are integrated only if there is a need to do so.

Moral roots of environmental attitudes.

From Feinberg and Willer:

Americans’ attitudes about the environment are highly polarized, but it is unclear why this is the case. We conducted five studies to examine this issue. The first two studies demonstrated that liberals, but not conservatives, view the environment in moral terms and that this tendency partially explains the relation between political ideology and environmental attitudes. The second two studies did content analyses of newspaper op-eds and public-service announcements and found that contemporary environmental discourse is based largely on moral concerns related to harm and care, which are more deeply held by liberals than by conservatives. However, in a final study we found that reframing proenvironmental rhetoric in terms of purity, a moral value resonating primarily among conservatives eliminated the difference between liberals’ and conservatives’ environmental attitudes. These results establish the importance of moralization as a cause of polarization on environmental attitudes and suggest that reframing environmental discourse in different moral terms can reduce the gap between liberals and conservatives in environmental concern.

The Biology of Fear

I want to point to a good open source review article in Current Biology on the brain correlates of fear, by Ralph Adolphs. You might find the summary graphics useful. The summary:

Each of us has felt afraid, and we can all recognize fear in many animal species. Yet there is no consensus in the scientific study of fear. Some argue that ‘fear’ is a psychological construct rather than something discoverable through scientific investigation. Others argue that the term ‘fear’ cannot properly be applied to animals because we cannot know whether they feel afraid. Studies in rodents show that there are highly specific brain circuits for fear, whereas findings from human neuroimaging seem to make the opposite claim. Here, I review the field and urge three approaches that could reconcile the debates. For one, we need a broadly comparative approach that would identify core components of fear conserved across phylogeny. This also pushes us towards the second point of emphasis: an ecological theory of fear that is essentially functional. Finally, we should aim even to incorporate the conscious experience of being afraid, reinvigorating the study of feelings across species.

You are going to die...

The "Opinionator" online commentary feature of the New York Times has another engaging contribution in its "Anxiety" series, from Tim Kreider, author of collections of essays and cartoons. He starts with a visit to a posh retirement community his mother has decided to enter, which she describes as "like a college dorm, except the boys aren't as good-looking." In spite of her enthusiasm, he feels sadness, which he then realizes is mainly selfish, because the family home he grew up in is being sold, the familiar phone number lost. Some clips of sections that struck me:

Plenty of people before me have lamented the way that we in industrialized countries regard our elderly as unproductive workers or obsolete products, and lock them away in institutions instead of taking them into our own homes out of devotion and duty...what I wonder about is what it's doing to the rest of us...I think we also segregate the elderly from the rest of society because we're afraid of them, as if age might be contagious. Which, it turns out, it is.

Segregating the old and the sick enables a fantasy, as baseless as the fantasy of capitalism's endless expansion, of youth and health as eternal, in which old age can seem to be an inexplicably bad lifestyle choice...So that when through absolutely no fault of your own your eyesight begins to blur and you can no longer eat whatever you want without consequence and the hangovers start lasting for days, you feel somehow ripped off, lied to. Aging feels grotesquely unfair. As if there ought to be someone to sue.

Because of all the stories we've absorbed, we vaguely imagine that our lives will take the shape of a narrative - the classic Aristotelian ramp diagram of gradual rising action (struggle and setbacks), climax (happy marriage, professional success), and a brief, cozy denoument (kicking back with family and friends, remembering the good times on a porch someplace pretty). But life is not shaped like a story; it's an elongate and flattened bell curve, with an attenuated, anticlimactic decline as long as its beginning. Friends have described seeing their parents lose their faculties one by one, in more or less the reverse order that their young children are acquiring them.

On the desire for life extension therapies:

I am all for raging against the dying of the light, and if they ever develop DNA rejuvenation or some other longevity technique I will personally claw, throttle and gouge my way through Warren Buffett, Rupert Murdoch and any number of other decrepit billionaires in order to be first in line.

But we don't have a choice. You are older at this moment than you've ever been before, and it's the youngest you're ever going to get. The mortality rate is holding at a scandalous 100 percent. Pretending death can be indefinitely evaded with hot yoga or a gluten-free diet or antioxidants or just by refusing to look is craven denial.

Thoughts as material objects - impact on evaluations

It's hard to get rid of unwanted thoughts. What about just throwing them in the garbage like unwanted objects? In some conditions might we discard our thoughts as easily as we dispose of objects? If Mr. Descartes was right (straw man, I know), a thought cannot literally be thrown into the garbage, because it does not have a material or physical nature. If a component of our cognition is taken to be a physical object, we should be able to discard it. Briñol et al. make some observations relevant to these points. Their experiments involved subjects writing down positive and negative thoughts about their bodies. First, their abstract:

In Western dualistic culture, it is assumed that thoughts cannot be treated as material objects; however, language is replete with metaphorical analogies suggesting otherwise. In the research reported here, we examined whether objectifying thoughts can influence whether the thoughts are used in subsequent evaluations. In a firstexperiment participants wrote about what they either liked or disliked about their bodies. Then, the paper on which they wrote their thoughts was either ripped up and tossed in the trash or kept and checked for errors. When participants physically discarded a representation of their thoughts, they mentally discarded them as well, using them less in forming judgments than did participants who retained a representation of their thoughts. A second experiment replicated this finding and also showed that people relied on their thoughts more when they physically kept them in a safe place—putting their thoughts in their pockets—than when they discarded them. A final study revealed that these effects were stronger when the action was performed physically rather than merely imagined.

Now, a bit more detail on the first experiment:

The experiment was presented as a study on body image. All participants received written instructions asking them to complete several tasks. As part of the first task, each participant was randomly assigned to generate and write down either positive or negative thoughts about his or her own body during a 3-min period. In the positive-thoughts condition, participants were told to list as many positive thoughts about their bodies as they could; in the negative-thoughts condition, participants were told to list as many negative thoughts about their bodies as they could (e.g., Killeya & Johnson, 1998). Examination of the thoughts listed indicated that all participants followed the instructions.

After listing his or her thoughts, each participant was randomly assigned to either the thought-disposal or the control condition. All participants were asked to look back at the thoughts they wrote. In the thought-disposal condition, participants were asked to contemplate their thoughts and then throw them into the trash can located in the room, because their thoughts did not have to remain with them. In the control condition, participants were asked to contemplate their thoughts and to check for any grammar or spelling errors they could find.

The dependent variable in our analysis was participants’ attitudes toward their bodies. Participants were told that they should record these attitudes because their self-image might have influenced their previous responses. Attitudes were assessed using three 9-point semantic-differential scales (e.g., bad-good, unattractive-attractive, like-dislike). Ratings were highly intercorrelated (α = .88), so we averaged them (after reverse scoring as appropriate) to create a composite attitude index. Higher values on this index indicated more favorable attitudes.

From their discussion:

Consistent with our hypothesis that a thought-disposal treatment can influence judgments by invalidating people’s thoughts, results showed that the attitudes of participants who physically threw their thoughts away showed less impact of the thought-direction induction than did the attitudes of participants who physically retained their thoughts....It is important to note that because the treatment was induced after thoughts were already generated, it could not affect the valence or the number of participants’ thoughts. Rather, the treatment decreased the strength of the influence that participants’ thoughts had on their attitudes.

What we should fear...

Gary Marcus does a review of some answers to the annual question of John Brockman's edge.org, "What *should* we be worried about?" On the question of whether we are psychologically and politically constituted to worry about what we most need to worry about, Marcus suggests:

that there is good reason to think that we are not inclined that way, both because of an inherent cognitive bias that makes us focus on immediate concerns (like getting our dishwasher fixed) to the diminishment of our attention to long-term issues (like getting enough exercise to maintain our cardiovascular fitness) and because of a chronic bias toward optimism known as a “just-world fallacy” (the comforting but unrealistic idea that moral actions will invariably lead to just rewards).

A theme throughout the collection is what Stanford psychologist Brian Knutson calls “metaworry”. His metaworry is that:

...actual threats [to our species] are changing much more rapidly than they have in the ancestral past. Humans have created much of this environment with our mechanisms, computers, and algorithms that induce rapid, “disruptive,” and even global change. Both financial and environmental examples easily spring to mind.… Our worry engines [may] not retune their direction to focus on these rapidly changing threats fast enough to take preventative action.

Brain correlates of developing intuition.

An interesting open access study from Wan et al.:

The superior capability of cognitive experts largely depends on automatic, quick information processing, which is often referred to as intuition. Intuition develops following extensive long-term training. There are many cognitive models on intuition development, but its neural basis is not known. Here we trained novices for 15 weeks to learn a simple board game and measured their brain activities in early and end phases of the training while they quickly generated the best next-move to a given board pattern. We found that the activation in the head of caudate nucleus developed over the course of training, in parallel to the development of the capability to quickly generate the best next-move, and the magnitude of the caudate activity was correlated with the subject's performance. In contrast, cortical activations, which already appeared in the early phase of training, did not further change. Thus, neural activation in the caudate head, but not those in cortical areas, tracked the development of capability to quickly generate the best next-move, indicating that circuitries including the caudate head may automate cognitive computations.

A few pictures showing location of the caudate head (pointed to by to line in right figure):

How procrastination gets things done...

John Tierney writes a delightful piece on not getting some things done. He notes several authors' comments on procrastination:

The key to productivity, John Perry argues in “The Art of Procrastination,” is to make more commitments — but to be methodical about it...At the top of your to-do list, put a couple of daunting, if not impossible, tasks that are vaguely important-sounding (but really aren’t) and seem to have deadlines (but really don’t). Then, farther down the list, include some doable tasks that really matter.,,“Doing these tasks becomes a way of not doing the things higher up on the list,” Dr. Perry writes. “With this sort of appropriate task structure, the procrastinator becomes a useful citizen. Indeed, the procrastinator can even acquire, as I have, a reputation for getting a lot done.”

Robert Benchley:

“The secret of my incredible energy and efficiency in getting work done is a simple one,” he wrote. “The psychological principle is this: anyone can do any amount of work, provided it isn’t the work he is supposed to be doing at that moment.”

Piers Steel ("The Procrastination Equation", 2011):

For most of us, procrastination can be beaten down, but not entirely beaten…My best trick is to play my projects off against each other, procrastinating on one by working on another….We are willing to pursue any vile task as long as it allows us to avoid something worse.

Procrastinators rarely sit around absolutely idle. The author Raymond Chandler forced himself to write detective stories by setting aside 4 hours each day with two rules:

a) You don’t have to write.

b) You can’t do anything else.

Another rule from Perry:

Never do today any task that may disappear by tomorrow.

Hedonic adaptation - where did the warm glow go?

Obtaining something we want follows a very stereotyped course, as noted in Oscar Wilde's famous aphorism: "There are only two tragedies in life: one is not getting what one wants, and the other is getting it." Or, consider the scene from the musical "Stop the World, I want to get off." in which the character at the climax of a song are entwined in a happy summation...the music stops...the characters keep holding their position, and keep holding....and keep holding...begin to wobble just a bit...wobble a bit more...and finally fall apart.

Why is the warm glow on attaining some we desire sustained? Why is happily-ever-after so rare? The issue, in terms of relationships, is addressed in Jane Brody recent review of writing and studies on keeping love alive in relationships. The happiness boost that occurs with marriage lasts only about two years, after which people revert to their former levels of happiness - or unhappiness, and infatuation and passion have even shorter life spans. The phenomenon is dubbed "hedonic adaptation" by psychologists - things that thrill us tend to be short-lived. (The reaction of many brain circuits to repeated stimulation is to decrease their reactivity or output, an example being the mesolimbic dopamine system, whose role in the brain reward system is controversial.)

 Lyubomirsky's new book "The Myth of Happiness" deals with this situation and notes techniques, backed by recent research, that help relationships evolve into companionate love, composed more of deep affection, connection and liking (I just downloaded a test sample from Amazon to my iPad to check it out). Barbara L. Fredrickson, author of the forthcoming "Love 2.0" specifies that a flourishing relationship needs three times as many positive emotions as negative ones.

The advice on relationships all seems to boil down to "practice a bit more kindness and gratitude".   I have to say, that when I've been able to budge my curmudgeonly nature enough to actually do this for brief periods of time, it has worked wonders!

How environments talk to genes.

The January issue of Nature Neuroscience has some fascinating articles on gene-environment interactions. Vassoler et al. report that in rats paternal cocaine use causes a heritable increase in cortical brain-derived neurotrophic factor (Bdnf) gene expression, which then confers a cocaine-resistant phenotype in male, but not female, progeny (The sins of the father are forgiven!):

We delineated a heritable phenotype resulting from the self-administration of cocaine in rats. We observed delayed acquisition and reduced maintenance of cocaine self-administration in male, but not female, offspring of sires that self-administered cocaine. Brain-derived neurotrophic factor (Bdnf) mRNA and BDNF protein were increased in the medial prefrontal cortex (mPFC), and there was an increased association of acetylated histone H3 with Bdnf promoters in only the male offspring of cocaine-experienced sires. Administration of a BDNF receptor antagonist (the TrkB receptor antagonist ANA-12) reversed the diminished cocaine self-administration in male cocaine-sired rats. In addition, the association of acetylated histone H3 with Bdnf promoters was increased in the sperm of sires that self-administered cocaine. Collectively, these findings indicate that voluntary paternal ingestion of cocaine results in epigenetic reprogramming of the germline, having profound effects on mPFC gene expression and resistance to cocaine reinforcement in male offspring.

And, Klengel et al. find a molecular mechanism in the case of post-traumatic stress disorder: demethylation of a glucocorticoid response element in the stress response regulator FKBP5 that depends on both the risk allele and childhood trauma. Here is the jargon:

Although the fact that genetic predisposition and environmental exposures interact to shape development and function of the human brain and, ultimately, the risk of psychiatric disorders has drawn wide interest, the corresponding molecular mechanisms have not yet been elucidated. We found that a functional polymorphism altering chromatin interaction between the transcription start site and long-range enhancers in the FK506 binding protein 5 (FKBP5) gene, an important regulator of the stress hormone system, increased the risk of developing stress-related psychiatric disorders in adulthood by allele-specific, childhood trauma–dependent DNA demethylation in functional glucocorticoid response elements of FKBP5. This demethylation was linked to increased stress-dependent gene transcription followed by a long-term dysregulation of the stress hormone system and a global effect on the function of immune cells and brain areas associated with stress regulation. This identification of molecular mechanisms of genotype-directed long-term environmental reactivity will be useful for designing more effective treatment strategies for stress-related disorders.

Our brains change operating modes during an eyeblink.

Nakano et al. suggest that an eye blink briefly gives our attentional network a rest, as activity shifts to the default network:

It remains unknown why we generate spontaneous eyeblinks every few seconds, more often than necessary for ocular lubrication. Because eyeblinks tend to occur at implicit breakpoints while viewing videos, we hypothesized that eyeblinks are actively involved in the release of attention. We show that while viewing videos, cortical activity momentarily decreases in the dorsal attention network after blink onset but increases in the default-mode network implicated in internal processing. In contrast, physical blackouts of the video do not elicit such reciprocal changes in brain networks. The results suggest that eyeblinks are actively involved in the process of attentional disengagement during a cognitive behavior by momentarily activating the default-mode network while deactivating the dorsal attention network.

Why mental arithmetic counts.

Price et al. show that brain activation during single digit arithmetic predicts high school math scores:

Do individual differences in the brain mechanisms for arithmetic underlie variability in high school mathematical competence? Using functional magnetic resonance imaging, we correlated brain responses to single digit calculation with standard scores on the Preliminary Scholastic Aptitude Test (PSAT) math subtest in high school seniors. PSAT math scores, while controlling for PSAT Critical Reading scores, correlated positively with calculation activation in the left supramarginal gyrus and bilateral anterior cingulate cortex, brain regions known to be engaged during arithmetic fact retrieval. At the same time, greater activation in the right intraparietal sulcus during calculation, a region established to be involved in numerical quantity processing, was related to lower PSAT math scores. These data reveal that the relative engagement of brain mechanisms associated with procedural versus memory-based calculation of single-digit arithmetic problems is related to high school level mathematical competence, highlighting the fundamental role that mental arithmetic fluency plays in the acquisition of higher-level mathematical competence.

Lifelong bilingualism enhances cognitive control in aging.

This work by Gold et al. makes me wish I had maintained the proficiency in German that I had in my college years:

Recent behavioral data have shown that lifelong bilingualism can maintain youthful cognitive control abilities in aging. Here, we provide the first direct evidence of a neural basis for the bilingual cognitive control boost in aging. Two experiments were conducted, using a perceptual task-switching paradigm, including a total of 110 participants. In Experiment 1, older adult bilinguals showed better perceptual switching performance than their monolingual peers. In Experiment 2, younger and older adult monolinguals and bilinguals completed the same perceptual task-switching experiment while functional magnetic resonance imaging (fMRI) was performed. Typical age-related performance reductions and fMRI activation increases were observed. However, like younger adults, bilingual older adults outperformed their monolingual peers while displaying decreased activation in left lateral frontal cortex and cingulate cortex. Critically, this attenuation of age-related over-recruitment associated with bilingualism was directly correlated with better task-switching performance. In addition, the lower blood oxygenation level-dependent response in frontal regions accounted for 82% of the variance in the bilingual task-switching reaction time advantage. These results suggest that lifelong bilingualism offsets age-related declines in the neural efficiency for cognitive control processes.

A great New Yorker Cover

I can't resist passing on the cover of the most recent issue of The New Yorker:

Mindfulness neuroscience

The journal Social Cognitive and Affective Neuroscience has released an issue devoted to studies of brain correlates of different kinds of meditation. One article, on compassion or loving-kindness meditation, is open access. For me, the crucial article is the last one, written by a senior guru of the brain imaging field, Michael Posner, and his colleague Yi-Yuan Tang, outlining theoretical and methodological issues in the field. They note that reviews of the field have:

..summarized four components of how mindfulness meditation may work: (i) attention regulation, (ii) body awareness, (iii) emotion regulation (including reappraisal, exposure, extinction and reconsolidation) and (iv) change in perspective on the self. The authors indicate that mindfulness practice comprises a process of enhanced self-regulation that can be differentiated into distinct but interrelated components. While these components are a start, future empirical work should identify additional components of mindfulness and establish to what extent the components involve distinct mechanisms.

Many studies have difficulties with appropriate control and comparison subjects:

Different control and comparison groups have been used in mindfulness research, such as waiting lists, active control groups and interventions designed to match the non-specific effects of mindfulness practices, such as trainer’s confidence, expectancy effects and group support... Ideally, participants would be randomly assigned to condition, and the conditions would be matched with the many non-specific factors that have been found to produce beneficial change... Random assignment allows the changes observed in mindfulness research to be reasonably attributed to the active ingredient of mindfulness practice per se rather than to pre-existing differences in the experimental and control groups. Therefore, moving the field will require the use of rigorous comparison conditions to which participants are randomly assigned.

In long-term studies, an active control is not possible. In studies of long-term practitioners such as monks with many thousands of hours of practice, it is challenging to find even a matched control group. We don’t know how the monks differed before meditation practice and other factors including the environment and low stress, which differ from any ‘matched’ control group.

Other issues are that the various studies employ different mindfulness techniques, stages of practice, or duration of training. (Motivated readers can request a copy of his article from me.)