Meditation alters autonomic and central nervous system interaction.

I pass on this new abstract from Tang et al, which makes observations that correlate with my own subjective experiences of meditation :

Five days of integrative body–mind training (IBMT) improves attention and self-regulation in comparison with the same amount of relaxation training. This paper explores the underlying mechanisms of this finding. We measured the physiological and brain changes at rest before, during, and after 5 days of IBMT and relaxation training. During and after training, the IBMT group showed significantly better physiological reactions in heart rate, respiratory amplitude and rate, and skin conductance response (SCR) than the relaxation control. Differences in heart rate variability (HRV) and EEG power suggested greater involvement of the autonomic nervous system (ANS) in the IBMT group during and after training. Imaging data demonstrated stronger subgenual and adjacent ventral anterior cingulate cortex (ACC) activity in the IBMT group. Frontal midline ACC theta was correlated with high-frequency HRV, suggesting control by the ACC over parasympathetic activity. These results indicate that after 5 days of training, the IBMT group shows better regulation of the ANS by a ventral midfrontal brain system than does the relaxation group. This changed state probably reflects training in the coordination of body and mind given in the IBMT but not in the control group. These results could be useful in the design of further specific interventions.

Arts and the Brain

From the Dana Foundation, accounts of several neuro-education conferences on linking the Arts and intelligence. , musical training changing brain networks, etc.

Enhanced attention skills in video game players.

The July issue of Neuropsychologia offers yet another article, by Dye et al., on how video games enhance attentional resources:

Previous research suggests that action video game play improves attentional resources, allowing gamers to better allocate their attention across both space and time. In order to further characterize the plastic changes resulting from playing these video games, we administered the Attentional Network Test (ANT) to action game players and non-playing controls aged between 7 and 22 years. By employing a mixture of cues and flankers, the ANT provides measures of how well attention is allocated to targets as a function of alerting and orienting cues, and to what extent observers are able to filter out the influence of task irrelevant information flanking those targets. The data suggest that action video game players of all ages have enhanced attentional skills that allow them to make faster correct responses to targets, and leaves additional processing resources that spill over to process distractors flanking the targets.

Genetic bias of our amygdala-mediated economic decisions

Yet another nugget from the group associated with Ray Dolan at University College, London.

Genetic variation at the serotonin transporter-linked polymorphic region (5-HTTLPR) is associated with altered amygdala reactivity and lack of prefrontal regulatory control. Similar regions mediate decision-making biases driven by contextual cues and ambiguity, for example the "framing effect." We hypothesized that individuals hemozygous for the short (s) allele at the 5-HTTLPR would be more susceptible to framing. Participants, selected as homozygous for either the long (la) or s allele, performed a decision-making task where they made choices between receiving an amount of money for certain and taking a gamble. A strong bias was evident toward choosing the certain option when the option was phrased in terms of gains and toward gambling when the decision was phrased in terms of losses (the frame effect). Critically, this bias was significantly greater in the ss group compared with the lala group. In simultaneously acquired functional magnetic resonance imaging data, the ss group showed greater amygdala during choices made in accord, compared with those made counter to the frame, an effect not seen in the lala group. These differences were also mirrored by differences in anterior cingulate–amygdala coupling between the genotype groups during decision making. Specifically, lala participants showed increased coupling during choices made counter to, relative to those made in accord with, the frame, with no such effect evident in ss participants. These data suggest that genetically mediated differences in prefrontal–amygdala interactions underpin interindividual differences in economic decision making.

A new brain correlate of intention.

We have another installment in the story of how our conscious intention to move involves brain processes parallel to those that actually command the movements. It has been known for some time that stimulation of the presupplementary motor area in clinical exploration before brain surgery can produce an 'urge to move.' Desmurget et al. now find that stimulating areas in the inferior posterior parietal cortex (usually presumed to be involved in sensory motor coordination, not volition) can cause an urge to move specific body parts. When stimulation intensity was increased in parietal areas, participants believed they had really performed these movements, although no electromyographic activity was detected. Stimulation of the premotor region triggered overt mouth and contralateral limb movements. Yet, patients firmly denied that they had moved. Conscious intention and motor awareness thus arise from increased parietal activity before movement execution. Here is a figure from the review of this work by Haggard.

Voluntary action. (Top) The premotor cortex prepares commands for voluntary actions triggered by external stimuli, whereas the presupplementary motor area prepares commands for internally generated "intentional" actions, which are then executed by the primary motor cortex. Signals containing copies of prepared motor commands are also sent to the parietal cortex, where they are used to predict sensory consequences of movement. (Bottom) The preparation of motor commands for voluntary movement by the presupplementary motor area causes a sense of urge. The inferior part of the posterior parietal cortex generates sensory representations of the predicted consequences of the movement.

Evolutionary change driven by sufficiency, not survival

Polymath Adam Gopnik writes a nice piece in the May 11 issue of The New Yorker titled "The Fifth Blade." The title refers to the appearance (evolution) of razors with increasingly (functionally irrelevant) numbers of blades since the Wilkinson Sword company started mass-producing stainless-steel blades in 1961. This is consonant with a new suggested principle of biological evolution, quite at variance with the classical view that innovation is borne out of a struggle for survival amidst limited resources - that in dull periods of plenty, stasis was supposed to rule.

The new idea is almost the opposite. Terrence Deacon, for instance, a professor of biological anthropology and linguistics at Berkeley, has argued that animals' appearance alters and their behavior changes - birds brighten and their songs grow elaborate - not in conditions of scarcity, where bird fights bird for every seed, but in landscapes of plentitude...once "selection pressure" lifts - once it doesn't matter so much if every claw kills, if every molar crunches - then the animal can do its own thing and find its own pleasures. This pattern makes for what Deacon calls "relaxed selection, like relaxed-fit jeans.

Relaxed evolution favors the Ronald Firbanks over the Cotton Mathers, the playful dandy over the sober saver. Relaxed selection explains creativity in language and literature: once we no longer have to pressure our bodies to chew and hunt, the big heads behind them, having nothing to do, start doing what they please. It isn't the struggle for existence but the serenity of entertainment that explains our lives. The brain starts thinking as the jaw relaxes. We human beings are all three-blade razors, Gillete Mach3 Turbos and Shick Xtreme3s, with needless cutting surfaces and useless batteries, buzzing away, wasting energy and look sexy, forged in plenty and thriving in abundance.

How the brain talks to itself - errors in emotional prediction

Gilbert and Wilson offer an engaging essay in the Philisophical Transactions of the Royal Society B (PDF here) titled: "Why the brain talks to itself: sources of error in emotional prediction." In trying to plan futures that involve more pleasure than pain, we perform mental simulations (previews) of future events, which produce affective reactions (premotions), which are then used as a basis for forecasts (predictions) about the future event’s emotional consequences. Their review summarizes several main sources of systematic errors of these predictions.

Previews have several problems of dissimilar content:

1. They provide a poor basis for prediction because they tend to be based on memories that are not representative of the future events that those previews were meant to simulate.
2. They tend to omit features that are incidental to the event but that nonetheless may have a significant impact on our emotional reactions to it.
3. They tend to emphasize the early occurring moments of the event in which emotions are likely to be the most intense.
4. They include comparisons that views do not. (Imaginary chips are readily compared to imaginary sardines, but real chips are not.)

Previews also have problems of dissimilar context:

...accurate predictions also require that the context in which previewing occurs be similar to the context in which viewing occurs, and as it turns out, this is not always the case either. Why do contexts matter? Premotions are not just reactions to previews; they are reactions to previews and to the context in which those previews are generated. That is why we feel happier when we preview chocolate cake while we are lying on a comfortable couch than on a bed of nails, or when we are hungry rather than sated.

Brain activation in cocaine addicts caused by drug words

From Goldstein et al. :

When exposed to drug conditioned cues (stimuli associated with the drug), addicted individuals experience an intense desire for the drug, which is associated with increased dopamine cell firing. We hypothesized that drug-related words can trigger activation in the mesencephalon, where dopaminergic cells are located. During functional magnetic resonance imaging (fMRI), 15 individuals with cocaine use disorders and 15 demographically matched healthy control subjects pressed buttons for color of drug-related versus neutral words. Results showed that the drug words, but not neutral words, activated the mesencephalon in the cocaine users only. Further, in the cocaine users only, these increased drug-related mesencephalic responses were associated with enhanced verbal fluency specifically for drug words. Our results for the first time demonstrate fMRI response to drug words in cocaine-addicted individuals in mesencephalic regions as possibly associated with dopaminergic mechanisms and with conditioning to language (in this case drug words). The correlation between the brief verbal fluency test, which can be easily administered (crucial for clinical studies), and fMRI cue reactivity could be used as a biomarker of neurobiological changes in addiction.

Stepping backwards enhances cognitive control.

From Koch et al., some interesting work on the role of body locomotion in the recruitment of control processes.:

In the most fundamental and literal sense, approach refers to decreasing, and avoidance to increasing, the physical distance between the self and the outside world. In our view, body locomotion most purely taps into this fundamental nature of approach and avoidance. In everyday life, individuals typically approach desired stimuli by stepping forward and avoid aversive stimuli by stepping backward

...The idea that body locomotion may trigger approach and avoidance orientations has, so far, not been tested...we expected that stepping backward would increase the recruitment of cognitive control relative to stepping forward. To test this prediction, we gauged cognitive functioning by means of a Stroop task immediately after a participant stepped in one direction. The Stroop task requires naming the color in which stimulus words are printed while ignoring their semantic meaning, which is actually processed more automatically than the color. Cognitive control is required to override the tendency to respond to the semantic meaning and instead respond to the color.

...our study showed that stepping backward significantly enhanced cognitive performance compared to stepping forward or sideways. Considering the effect size, backward locomotion appears to be a very powerful trigger to mobilize cognitive resources. Thus, whenever you encounter a difficult situation, stepping backward may boost your capability to deal with it effectively.

Putting Off Growing Old

I pass on this item by Sherman Sutter from the editor's choice section of Science Magazine:

In a classic 1957 paper on the evolution of senescence, Williams argued that when extrinsic mortality (death due to predation, infectious disease, or accident) is high, natural selection favors investment in early reproduction. When it is low, the increased return from allocating resources to maintain and repair the soma should lead to longer life spans. In the absence of precise information on causes of death, researchers have used hazard models to partition mortality into age-independent (interpreted as extrinsic) and age-dependent components.

Taking this approach, Gurven and Fenelon analyze mortality data from 13 remote, small-scale societies and in historical cohorts from Sweden and England over the past 250 years. They explore two statistical models (Weibull and Gompertz-Makeham) of adult mortality patterns and consider three measures of actuarial aging (mortality rate doubling time, Ricklefs's {omega}, and slope of the mortality function between ages 60 and 70). The variation in results across these two estimation procedures and three measures complicates the interpretation of the data. Nonetheless, some patterns are robust: The subsistence groups and the early Swedish cohorts exhibit similar actuarial aging, but more recent European cohorts show progressively slower aging. In the longitudinal samples, slower aging and reduced extrinsic mortality are linked. Women have lower rates of senescence than men, a difference that has increased over time. These "modest but nontrivial" changes support Williams's claims, and the authors discuss individual-level mechanisms that could underlie them.

Experience as what we agree to attend to...

I have decided to paste in just a fragment of writing from a parallel private journal that I keep. It has some of my private jargon, apologies if it is not intelligible to you. It is a random walk...

...that wants to try to crystallize something from last Wednesday’s post on attention together with a reading (still going on) of Metzinger’s recent book “The Ego Tunnel.” Metzinger’s compelling analysis, along with others, shows our introspective selves to be fictions even if they are imaged to fit in a metacognitive hierarchy, such as a watcher (closer to a Damasio-style homeostatic pre-emotional core) that is sensed as observer of its products (being an angry/happy/kind/compassionate/whatever person.) All are actually logically equivalent (watch-ing, be-ing, angry-ing, desire-ing, compassion-ing). Even while being in principle illusory, many of these self models can be shown to correlate with distinctive pattern of brain activity, can be altered by brain lesions. The experiential and behavioral issue is which of these members of an imaginary governing board is being held within the limited attentional resources of the frontal lobes. (William James: “My experience is what I agree to attend to.”). Training regimes that settle this issue by putting in place new habits for what is held in attention (compassion meditation, piano or other athletic practice, etc.) can be transformative. Physical changes in brain areas serving these functions can be documented.

Prelinguistic infants, but not chimps, signal absent entities

Interesting work from Tomasello's group showing that nonlinguistic skills for displaced reference precede and underlie similar linguistic reference:

One of the defining features of human language is displacement, the ability to make reference to absent entities. Here we show that prelinguistic, 12-month-old infants already can use a nonverbal pointing gesture to make reference to absent entities. We also show that chimpanzees—who can point for things they want humans to give them—do not point to refer to absent entities in the same way. These results demonstrate that the ability to communicate about absent but mutually known entities depends not on language, but rather on deeper social-cognitive skills that make acts of linguistic reference possible in the first place. These nonlinguistic skills for displaced reference emerged apparently only after humans' divergence from great apes some 6 million years ago.

In carrying out the experiments the authors:

...confronted 12-month-old prelinguistic human infants and adult chimpanzees with two new situations in which they wanted something they could not see. In both situations, participants first repeatedly saw a human adult place several desired objects of the same kind on top of one platform, while also placing undesired objects of another kind on another, similar platform. Then, for the test, the desired objects were removed. In the occluded-referent condition, participants then saw the adult take another object of the desired kind and place it under its platform, out of sight. In this case, even though participants could not see the desired object, they knew it was there under the platform, and so they could potentially request it by pointing to its location. In the absent-referent condition, in contrast, after the adult removed the desired objects from the platform, she did not add any more, so that the usual location of the desired kind of objects was empty. In this case, if participants pointed to the now-empty platform, it would mean that they expected the adult would be able to infer that what they wanted was one of the missing kind of objects, that is, one of the kind both the adult and the participants knew was usually on that platform.

Judging honesty by story telling.

Benedict Carey summarizes work on detecting lying, not by body language cues, but by what people say. People telling the truth tend to add 20 to 30 percent more external detail than do those who are lying. If you’re telling the truth, this mental reinstatement of contexts triggers more and more external details. Not so if you’ve got a concocted story and you’re sticking to it. “It’s the difference between a tree in full flower in the summer and a barren stick in winter."

Antioxidants bad for you?

Check out this open access article by Ristow and et al.

Ramachandran and the plastic brain.

John Colapinto writes a New Yorker article on Vilayanur Ramachandran, whose work I have mentioned several times (actually, in six postings...enter Ramachandran in the search box in the left column to bring them up.) It is a biographical account, describing Ramachandran's professional development, and also describes an interesting syndrome known as apotemnophilia, the compulsion to have a healthy limb amputated. It appears to result from damage to the right superior parietal lobe which causes it to fail in assembling a normal body image for the body part perceived as alien, wanting amputation. Just as was the case with phantom limb pain and stroke induced paralysis, Ramachandran found that use of a simple mirror to differently present a body part could alleviate the symptoms. The article also describes work which suggests a link between autism and defects in the mirror neuron system.

Misconceptions of Memory: The Scooter Libby Effect

Some clips from a recent article from Daniel Gilbert and collaborators (Gilbert is the guy who wrote "Stumbling on Happiness" that I abstracted several years ago on this blog):

...during his 2007 trial, Vice-Presidential Chief of Staff I. Lewis "Scooter" Libby claimed that he could not remember mentioning the identity of a Central Intelligence Agency employee to other government officials or reporters. Jurors found it difficult to believe that Libby could have forgotten having had such important conversations and found him guilty of obstruction of justice, making false statements, and perjury
...Libby's conversations were indeed important, but they were less important at the time he had them than they became months later when the Justice Department launched its investigation. Although important information increases the motivation to remember (MTR), research on human memory suggests that MTR is considerably more effective when it arises before rather than after information is encoded...Do people take the timing of MTR into account when judging other people's memories?

Here is the experimental design:

Memorizers were told that they would study the material for 2 min before seeing the photographs and trying to recall the facts associated with each. They were also told that they would receive $0.10 for each recalled fact. Before they studied the material, memorizers in the MTR-at-encoding condition (n= 21) were told that they would receive a $0.50 bonus for each fact they remembered about the individual named Beryl White. Memorizers in the MTR-at-retrieval condition (n= 22) were told about this bonus immediately after they studied the material. Memorizers in the no-MTR condition (n= 21) were not told about the bonus. After studying the material, memorizers were shown the photograph of Beryl White and were asked to recall the facts about her.

Judges were shown the same material as memorizers and read a detailed description of the instructions from the MTR-at-encoding condition (n= 24), the MTR-at-retrieval condition (n= 21), or the no-MTR condition (n= 21). Judges were then asked to predict the percentage of memorizers in that condition who would remember each fact.

The results, shown in this figure, were extremely clear:

Participants who were asked to judge another individual's memory did not distinguish between information that was important when the individual encountered it and information that became important only later. Clearly, people's theories about the effects of motivation on memory are imperfect. It is interesting to note, in light of these findings, that the U.S. District Court denied Libby's motion to allow expert psychologists to testify about the foibles of memory and metamemory because, the court argued, such research would tell jurors little that they did not already know.

Brain correlates of self-transcendent emotions

Antonio and Hanna Damasio and collaborators have now observed brain activities associated with our internal loftier emotions that transcend self-interest, such as elevation and admiration. These are hard to measure because they don't correlate obviously with facial expressions or body language. Haidt and Morris, in their commentary in the same issue of PNAS, set the context for the work:

Emotion research has something in common with a drunk searching for his car keys under a street lamp. ‘‘Where did you lose them?’’ asks the cop. ‘‘In the alley,’’ says the drunk, ‘‘but the light is so much better over here.’’ For emotion research, the light shines most brightly on the face, whose movements can be coded, compared across cultures, and quantified by electromyography. All of the ‘‘basic’’ emotions described by Paul Ekman and others (happiness, sadness, anger, fear, surprise, and disgust) earned their place on the list by being face-valid. The second source of illumination has long been animal research. Emotions that can be reliably triggered in rats, such as fear and anger, have been well-studied, down to specific pathways through the amygdala. But emotions that cannot be found on the face or in a rat, such as moral elevation and admiration, are largely abandoned back in the alley. We know they are there, but nobody can seem to find a flashlight. It is therefore quite an achievement that Immordino-Yang, McCall, Damasio, and Damasio managed to drag an fMRI scanner back there and have given us a first glimpse of the neurological underpinnings of elevation and admiration.

Here is the abstract and a figure from the paper:

In an fMRI experiment, participants were exposed to narratives based on true stories designed to evoke admiration and compassion in 4 distinct categories: admiration for virtue (AV), admiration for skill (AS), compassion for social/psychological pain (CSP), and compassion for physical pain (CPP). The goal was to test hypotheses about recruitment of homeostatic, somatosensory, and consciousness-related neural systems during the processing of pain-related (compassion) and non-pain-related (admiration) social emotions along 2 dimensions: emotions about other peoples' social/psychological conditions (AV, CSP) and emotions about others' physical conditions (AS, CPP). Consistent with theoretical accounts, the experience of all 4 emotions engaged brain regions involved in interoceptive representation and homeostatic regulation, including anterior insula, anterior cingulate, hypothalamus, and mesencephalon. However, the study also revealed a previously undescribed pattern within the posteromedial cortices (the ensemble of precuneus, posterior cingulate cortex, and retrosplenial region), an intriguing territory currently known for its involvement in the default mode of brain operation and in self-related/consciousness processes: emotions pertaining to social/psychological and physical situations engaged different networks aligned, respectively, with interoceptive and exteroceptive neural systems. Finally, within the anterior insula, activity correlated with AV and CSP peaked later and was more sustained than that associated with CPP. Our findings contribute insights on the functions of the posteromedial cortices and on the recruitment of the anterior insula in social emotions concerned with physical versus psychological pain.


Figure (click to enlarge). Relative activation in the posteromedial cortices (PMC, outlined in pink) for admiration for virtue and compassion for social pain (AV/CSP, blue3 green) versus admiration for skill and compassion for physical pain (AS/CPP, orange 3 yellow). The image is thresholded at q(FDR)  0.05. The bar to the right provides a color code for t statistics associated with the contrast. The red box frames the location of the magnified view. Note the clear separation between the anterosuperior sector activated by AS/CPP, and the posteroinferior activated by AV/CSP.

As an added note: The commentary by Haidt and Morris offers an interesting table summarizing the number of articles on the main moral emotions other than compassion (on which a lot has been done), showing the number of articles in the PsycINFO database for which the emotion name was in the title or keywords fields.

The amazing aging brain - continued

This website on aging created by the Oregon Museum of Science and Industry has shifted locations quite a bit since I first mentioned it. My thanks to MindBlog reader Maryann S. Marino for tracking it down.

Gross national happiness

Seth Mydans describes how the tiny Himalayan kingdom of Bhutan (population ~700,000) is making an effort to replace GNP (gross national product) with GNH (gross national happiness) as the most meaningful indicator of a nation's health. After the World Bank and the I.M.F. essentially said OK.......but how do you measure it?, the government devised an intricate model of well-being, that in true Buddhist form, gets into huge lists and sub-lists: the four pillars, nine domains, and 72 indicators of happiness.

Gross national happiness has a broader application for Bhutan as it races to preserve its identity and culture from the encroachments of the outside world...Bhutan is pitting its four pillars, nine domains and 72 indicators against the 48 channels of Hollywood and Bollywood that have invaded since television was permitted a decade ago...Before June 1999 if you asked any young person who is your hero, the inevitable response was, ‘The king,’ Immediately after that it was David Beckham, and now it’s 50 Cent, the rap artist. Parents are helpless...So if G.N.H. may hold the secret of happiness for people suffering from the collapse of financial institutions abroad, it offers something more urgent here in this pristine culture.

The neuroeconomics of taking your pick.

Whaley offers a summary of papers by Martino et al. (open access) and Sharot et al. in a recent issue of J. Neurosci and a more recent paper by Croxson et al. notes correlates of cost-benefits valuation. Excerpts from Whaley:

To deal with the countless decisions that it makes, the brain must assign values to each available option. However, the perceived value of an option can be influenced by multiple factors. Two recent papers shed light on the brain regions involved in the neural representation of value.

Choosing between several equally appealing options is difficult; however, once a decision is made, our expectations of our chosen option's value often become inflated with respect to that of the rejected alternatives. Sharot et al. carried out functional MRI (fMRI) of participants as they estimated how much they would enjoy vacationing in various destinations before and after choosing one of two equally rated vacations. This demonstrated that the relative sizes of the blood oxygen level-dependent (BOLD) signals in the caudate nucleus in response to the initial presentation of the destinations predicted subsequent choices. As expected, after making their selection, participants rated their chosen destination higher than the rejected destination. Furthermore, the differences in the caudate nucleus BOLD signal response to selected versus rejected options increased after the selection, suggesting that the act of choosing can itself alter the neurobiological representation of an option's value.

The 'endowment effect' is our tendency to value objects that we own and are selling more highly than identical objects belonging to others that we are thinking of buying. It is thought to arise because an object's value with respect to a reference point (in this case, owning the item) is altered by the individual's position as buyer or seller in the transaction. De Martino et al. asked participants how much they would accept in payment for or spend on lottery tickets with different expected payoffs. fMRI showed that activity in the ventral striatum correlated highly with the behavioural tendency to overvalue items when selling and undervalue items when buying, suggesting that this region contributes to the reference-dependent valuation of items.

These two studies provide insights into some of the neural mechanisms involved in encoding value in the brain and how these representations may be altered by previous decisions or social context.