Science of minus 10 Biology iPad App

I've been cruising the annual best science and engineering visualization competition sponsored every year by Science Magazine and the National Science Foundation (see also Wired Magazine account.). I find especially compelling the game "Powers of Ten", which allows players to zoom into a person’s hand, explore the world at different magnifications and learn about the human body:

Our brains as prediction machines - a unified view of mind and action

Anything Andy Clark writes is totally worth reading (I used his charming essay "I am John's brain" when I first began teaching my "Biology of Mind Course" at the University of Wisconsin in the 1990's), and so I pass on this manuscript of an article on which comments are currently being solicited.  It is a fascinating read, lucidly and clearly written. 

"Whatever Next? Predictive Brains, Situated Agents, and the Future of Cognitive Science"

Abstract: Brains, it has recently been argued, are essentially prediction machines. They are bundles of cells that support perception and action by constantly attempting to match incoming sensory inputs with top-down expectations or predictions. This is achieved using a hierarchical generative model that aims to minimize prediction error within a bidirectional cascade of cortical processing.  Such accounts offer a unifying model of perception and action, illuminate the functional role of attention, and may neatly capture the special contribution of cortical processing to adaptive success. The paper critically examines this 'hierarchical prediction machine' approach, concluding that it offers the best clue yet to the shape of a unified science of mind and action. Sections 1 and 2 lay out the key elements and implications of the approach. Section 3 explores a variety of pitfalls and challenges, spanning the evidential, the methodological, and the more properly conceptual. The paper ends (sections 4 and 5) by asking how such approaches might impact our more general vision of mind, experience, and agency. 

Our brain's grasp of metaphors grounded in perception?

Theories of grounded cognition suggest that knowledge is represented in modal systems derived from perception (rather than abstract brain codes) and that cognition depends on perceptual simulations. Conceptual metaphor theory is one approach to grounded cognition which suggests that knowledge is structured by metaphorical mappings from sensory experience. Sathian and colleagues do a interesting experiment in which they find that textural metaphors — phrases like "soft-hearted"— turn on a part of the brain (the parietal operculum) that's important to the sense of touch. This doesn't happen with literal counterparts: "he is wet behind the ears" versus "he is naïve," for example, or "it was a hairy situation" versus "it was a precarious situation."

Figure - Touching actives areas shown in yellow and red. Textural metaphors also trigger a reaction (shown in green and, where overlapping, brown) in the parietal operculum.

It would be interesting to see if a subject's appreciation of a tactile metaphor was compromised by transcranial magnetic stimulation that disrupted activity of the parietal operculum.

Negative social interactions and body inflammation.

Many studies have proven that social relationships influence our physical health. People who are more socially integrated live longer, and are less likely to have medical problems such as heart attacks and upper respiratory illness. (Cytokines are small protein molecules - peptides - that regulate our inflammatory immune response. While transient inflammatory response due to tissue insult are adaptive and trigger needed immune responses, chronic increases in proinflammatory cytokines IL-6 and TNF-α are linked hypertension, atherosclerosis, coronary heart disease, depression, diabetes, and some cancers.) Chiang et al. now show that these cytokines promoting tissue inflammation appear when we are in socially stressful situations:

Research has consistently documented that social relationships influence physical health, a link that may implicate systemic inflammation. We examined whether daily social interactions predict levels of proinflammatory cytokines IL-6 and the soluble receptor for tumor necrosis factor-α (sTNFαRII) and their reactivity to a social stressor. One-hundred twenty-two healthy young adults completed daily diaries for 8 d that assessed positive, negative, and competitive social interactions. Participants then engaged in laboratory stress challenges, and IL-6 and sTNFαRII were collected at baseline and at 25- and 80-min poststressor, from oral mucosal transudate. Negative social interactions predicted elevated sTNFαRII at baseline, and IL-6 and sTNFαRII 25-min poststressor, as well as total output of sTNFαRII. Competitive social interactions predicted elevated baseline levels of IL-6 and sTNFαRII and total output of both cytokines. These findings suggest that daily social interactions that are negative and competitive are associated prospectively with heightened proinflammatory cytokine activity.

How psychedelics affect our brain - unconstrained cognition

Carhart-Harris et al. have done an interesting study showing that psilocybin decreases surrogate markers for neuronal activity [cerebral blood flow and blood oxygen level-dependent (BOLD) signals] in key brain regions implicated in psychedelic drug actions. They also report that psilocybin appears to decrease brain “connectivity” as measured by pharmaco-physiological interaction. Their results imply that "the subjective effects of psychedelic drugs are caused by decreased activity and connectivity in the brain's key connector hubs, enabling a state of unconstrained cognition."

Psychedelic drugs have a long history of use in healing ceremonies, but despite renewed interest in their therapeutic potential, we continue to know very little about how they work in the brain. Here we used psilocybin, a classic psychedelic found in magic mushrooms, and a task-free functional MRI (fMRI) protocol designed to capture the transition from normal waking consciousness to the psychedelic state. Arterial spin labeling perfusion and blood-oxygen level-dependent (BOLD) fMRI were used to map cerebral blood flow and changes in venous oxygenation before and after intravenous infusions of placebo and psilocybin. Fifteen healthy volunteers were scanned with arterial spin labeling and a separate 15 with BOLD. As predicted, profound changes in consciousness were observed after psilocybin, but surprisingly, only decreases in cerebral blood flow and BOLD signal were seen, and these were maximal in hub regions, such as the thalamus and anterior and posterior cingulate cortex (ACC and PCC). Decreased activity in the ACC/medial prefrontal cortex (mPFC) was a consistent finding and the magnitude of this decrease predicted the intensity of the subjective effects. Based on these results, a seed-based pharmaco-physiological interaction/functional connectivity analysis was performed using a medial prefrontal seed. Psilocybin caused a significant decrease in the positive coupling between the mPFC and PCC. These results strongly imply that the subjective effects of psychedelic drugs are caused by decreased activity and connectivity in the brain's key connector hubs, enabling a state of unconstrained cognition.

Brain deactivations after psilocybin. (Upper) Regions where there was a significant decrease in the BOLD signal after psilocybin versus after placebo. (Lower) Regions where there was a consistent decrease in CBF (cerebral blood flow) and BOLD after psilocybin. We observed no increases in CBF or BOLD signal in any region.

Life is a digital code.

Here is a nicely done precis of a crucial bit of our intellectual history from science written by Matt Ridley, his answer to "What is your favorite deep, elegant or beautiful explanation.":

It's hard now to recall just how mysterious life was on the morning of 28 February and just how much that had changed by lunchtime. Look back at all the answers to the question "what is life?" from before that and you get a taste of just how we, as a species, floundered. Life consisted of three-dimensional objects of specificity and complexity (mainly proteins). And it copied itself with accuracy. How? How do you set about making a copy of a three-dimensional object? How to do you grow it and develop it in a predictable way? This is the one scientific question where absolutely nobody came close to guessing the answer. Erwin Schrodinger had a stab, but fell back on quantum mechanics, which was irrelevant. True, he used the phrase "aperiodic crystal" and if you are generous you can see that as a prediction of a linear code, but I think that's stretching generosity.

Indeed, the problem had just got even more baffling thanks to the realization that DNA played a crucial role—and DNA was monotonously simple. All the explanations of life before 28 Feb 1953 are hand-waving waffle and might as well speak of protoplasm and vital sparks for all the insights they gave.

Then came the double helix and the immediate understanding that, as Crick wrote to his son a few weeks later, "some sort of code"—digital, linear two-dimensional, combinatorially infinite and instantly self-replicating—was all the explanation you needed. Here's part of Francis Crick's letter, 17 March 1953:

"My Dear Michael,

Jim Watson and I have probably made a most important discovery...Now we believe that the DNA is a code. That is, the order of the bases (the letters) makes one gene different from another gene (just as one page pf print is different from another). You can see how Nature makes copies of the genes. Because if the two chains unwind into two separate chains, and if each chain makes another chain come together on it, then because A always goes with T, and G with C, we shall get two copies where we had one before. In other words, we think we have found the basic copying mechanismby which life comes from life...You can understand we are excited."

Never has a mystery seemed more baffling in the morning and an explanation more obvious in the afternoon.

Testosterone, digit ratio, and abstract reasoning ability

Brañas-Garza and Aldo Rustichini suggest that perhaps higher testosterone market traders are more successful not only because they are greater risk takers, but also because their abstract reasoning abilities are superior:

Recent literature emphasizes the role that testosterone, as well as markers indicating early exposure to T and its organizing effect on the brain (such as the ratio of second to fourth finger, ), have on performance in financial markets. These results may suggest that the main effect of T, either circulating or in fetal exposure, on economic behavior occurs through the increased willingness to take risks. However, these findings indicate that traders with a low digit ratio are not only more profitable, but more able to survive in the long run, thus the effect might consist of more than just lower risk aversion. In addition, recent literature suggests a positive correlation between abstract reasoning ability and higher willingness to take risks. To test the two hypotheses of testosterone on performance in financial activities (effect on risk attitude versus a complex effect involving risk attitude and reasoning ability), we gather data on the three variables in a sample of 188 ethnically homogeneous college students (Caucasians). We measure a digit ratio, abstract reasoning ability with the Raven Progressive Matrices task, and risk attitude with choice among lotteries. Low digit ratio in men is associated with higher risk taking and higher scores in abstract reasoning ability when a combined measure of risk aversion over different tasks is used. This explains both the higher performance and higher survival rate observed in traders, as well as the observed correlation between abstract reasoning ability and risk taking. We also analyze how much of the total effect of digit ratio on risk attitude is direct, and how much is mediated. Mediation analysis shows that a substantial part of the effect of T on attitude to risk is mediated by abstract reasoning ability.

Us vs. them in context.

As I scan the tables of contexts of journals for items that might be appropriate for MindBlog, I am majorly influenced by a catchy title and relative brevity, the old brain doesn’t have to work as hard. (In this vein, see the recent essay on "Bite Size" Science.) Gilbert Chin of Science Magazine notes that a plain title I passed over points to an interesting piece of work, showing that our attitude towards pluralism and tolerance can depend very much on whether we are in the majority or minority of the relevant social group. From Chin's summary:

Us versus Them is both an enduring view of the world and a malleable one. It is enduring in the sense that groups form naturally even where there are no preexisting differences and malleable in the sense that the group that one identifies with can change over time or between situations. Theoretical and empirical evidence justifies the generalization that members of a majority group tend to favor the assimilation of immigrants into the native culture, whereas immigrants are more likely to vote for pluralistic policies that acknowledge the distinctiveness of minority cultures.

The abstract of the article:

This research examined preferences for national- and campus-level assimilative and pluralistic policies among Black and White students under different contexts, as majority- and minority-group members. We targeted attitudes at two universities, one where 85% of the student body is White, and another where 76% of students are Black. The results revealed that when a group constituted the majority, its members generally preferred assimilationist policies, and when a group constituted the minority, its members generally preferred pluralistic policies. The results support a functional perspective: Both majority and minority groups seek to protect and enhance their collective identities.

Even if the juice is a placebo...

I thought the stuff on the oxytocin spray in the previous post was a hoot, and so dashed off the post on receiving a colleague's email on it yesterday.  Several alert readers have immediately sent in appropriately skeptical comments.  Cursory inspection of the website shows the product to be from a homeopathic outfit, the product description actually gives NO CLUE on how much oxytocin (plus a lot of other claimed stuff) is present.  But hey.... I guess $50 for the product should reinforce a pretty good placebo effect!

Juice up your Valentine's day!

I've done numerous posts on oxytocin effects on us humans (enter oxytocin in the search box in the left column). Generally, it makes us nicer and more affiliative. A recent email from a colleague who diligently sends me results of his wide ranging web scans for enhancers of vitality, longevity, etc. makes me aware that getting a nip of oxytocin for yourself is like falling off a log (if you are also willing to part with ~50-60 dollars for nasal or sublingual versions). He has tried the sub-lingual spray and says it does work "although the subjective results are highly-dependent upon my physiological/mental state and/or the time of day. There are also quite likely different genetic predispositions as reported in Deric's mind blog." I would be curious to try the stuff, but don't want to threaten the curmudgeonly behavior that I normally enjoy.

Don't go to bed angry...

Several studies have shown that sleep enhances emotional memories. Baran et al. show that maybe its better let anger keep you awake at night than to sleep on it. Sleep consolidates the negative emotional memory. Having trouble sleeping after an unsettling experience may be the brain's way of trying to keep the memory or emotion from being stored. The abstract:

Sleep enhances memories, particularly emotional memories. As such, it has been suggested that sleep deprivation may reduce posttraumatic stress disorder. This presumes that emotional memory consolidation is paralleled by a reduction in emotional reactivity, an association that has not yet been examined. In the present experiment, we used an incidental memory task in humans and obtained valence and arousal ratings during two sessions separated either by 12 h of daytime wake or 12 h including overnight sleep. Recognition accuracy was greater following sleep relative to wake for both negative and neutral pictures. While emotional reactivity to negative pictures was greatly reduced over wake, the negative emotional response was relatively preserved over sleep. Moreover, protection of emotional reactivity was associated with greater time in REM sleep. Recognition accuracy, however, was not associated with REM. Thus, we provide the first evidence that sleep enhances emotional memory while preserving emotional reactivity.

Our connectomes 'R Us?

I have received by now several offers from Houghton Mifflin publishers to send a reviewer's copy of Sebastian Seung's "Connectome: How the Brain's Wiring Makes Us Who We Are." I haven't acted on it, because a review of the synopsis has convinced me that Seung's own brilliant efforts, and similar works he describes to map every connection in our brain, are not the complete key to understanding ourselves that he implies. I was actually starting to write a list of problems I see with the idea that when you've got the wiring diagram between nerve cells you've got it all, but this succinct critique by Chris Koch permits me to be lazy:

Treating the connectome as the be-all and end-all of brain function has its problems. Seung, for example, rebrands autism and schizophrenia as 'connectopathies' — diseases in which the brain's wiring goes awry. Yet plenty of other things are wrong in brains with these disorders besides their connectivity.

Faults in synaptic transmission and in processes inside neurons and the glial cells that support them have all been implicated in mental illness and brain disease. Neurons are intricate devices with elaborate input structures that show complex, time-dependent and nonlinear processing. They have various characteristic, and often tortuous, morphologies. Connectionism treats all this as irrelevant. Even though we have known the connectome of the nematode worm for 25 years, we are far from reading its mind. We don't yet understand how its nerve cells work.

Massage therapy suppresses expression of inflammatory genes after exercise..

I've been getting regular deep tissue structural massage for years, and continue to be amazed at how good it makes me feel. This report from Tarnopolsky and colleagues explains at least part of the reason why. They profiled the expression of genes involved in both inflammatory pathways and in pathways that regenerate energy generating mitochondria in the leg muscles of eleven young men after very strenuous leg exercise, with one leg being massaged after the exercise. The massaged legs had 30% more PGC-1alpha, a gene that helps muscle cells build mitochondria. They also had three times less NFkB, which turns on genes associated with inflammation. (The study found no evidence to support often-repeated claims that massage removes lactic acid, a byproduct of exertion long blamed for muscle soreness, or waste products from tired muscles.) Here is the detailed abstract:

Massage therapy is commonly used during physical rehabilitation of skeletal muscle to ameliorate pain and promote recovery from injury. Although there is evidence that massage may relieve pain in injured muscle, how massage affects cellular function remains unknown. To assess the effects of massage, we administered either massage therapy or no treatment to separate quadriceps of 11 young male participants after exercise-induced muscle damage. Muscle biopsies were acquired from the quadriceps (vastus lateralis) at baseline, immediately after 10 min of massage treatment, and after a 2.5-hour period of recovery. We found that massage activated the mechanotransduction signaling pathways focal adhesion kinase (FAK) and extracellular signal–regulated kinase 1/2 (ERK1/2), potentiated mitochondrial biogenesis signaling [nuclear peroxisome proliferator–activated receptor γ coactivator 1α (PGC-1α)], and mitigated the rise in nuclear factor κB (NFκB) (p65) nuclear accumulation caused by exercise-induced muscle trauma. Moreover, despite having no effect on muscle metabolites (glycogen, lactate), massage attenuated the production of the inflammatory cytokines tumor necrosis factor–α (TNF-α) and interleukin-6 (IL-6) and reduced heat shock protein 27 (HSP27) phosphorylation, thereby mitigating cellular stress resulting from myofiber injury. In summary, when administered to skeletal muscle that has been acutely damaged through exercise, massage therapy appears to be clinically beneficial by reducing inflammation and promoting mitochondrial biogenesis.

The good life can be a killer.

I've enjoyed the recent piece on our dysfunctional modern community structures by Jane Brodie (who got her journalism degree at the University of Wisconsin, Madison, where I teach).

...homes and shopping malls far from city centers…[have created] creating vehicle-dependent environments that foster obesity, poor health, social isolation, excessive stress and depression…Physical activity has been disappearing from the lives of young and old, and many communities are virtual “food deserts,” serviced only by convenience stores that stock nutrient-poor prepared foods and drinks…people in the current generation (born since 1980) will be the first in America to live shorter lives than their parents do.

In a healthy environment…people who are young, elderly, sick or poor can meet their life needs without getting in a car, which means creating places where it is safe and enjoyable to walk, bike, take in nature and socialize…People who walk more weigh less and live longer…People who are fit live longer… People who have friends and remain socially active live longer…In 1974, 66 percent of all children walked or biked to school By 2000, that number had dropped to 13 percent…We’ve engineered physical activity out of children’s lives…two in seven volunteers for the military can’t get in because they’re not in good enough physical condition…Not only are Americans of all ages fatter than ever, but also growing numbers of children are developing diseases once seen only in adults: Type 2 diabetes, heart disease and fatty livers.

On the question of whether our suburbs can be saved, Brodie notes environmental redesigning projects to foster better physical and mental health proceeding in Atlanta, GA., Lakewood, CO., Syracuse, NY, and Elgin, IL. (and, see designinghealthycommunities.org.)

Should I use condoms for sex? The millisecond scan.

This item caught my eye, since I spend the winter months each year living in the center of the gay Wilton Manors ghetto of Fort Lauderdale, FL., where the boys hook up at a fast and furious rate. Many base a decision on whether to use condoms on their 'intuition' of whether a potential partner is HIV positive. Renner et al. find that this guessing is very rapid and based on a few fairly simple facial trait characteristics (that in fact have not been shown to have any relationship to actual HIV status).

Research indicates that many people do not use condoms consistently but instead rely on intuition to identify sexual partners high at risk for HIV infection. The present studies examined neural correlates for first impressions of HIV risk and determined the association of perceived HIV risk with other trait characteristics. Participants were presented with 120 self-portraits retrieved from a popular online photo-sharing community (www.flickr.com). Factor analysis of various explicit ratings of trait characteristics yielded two orthogonal factors: (1) a ‘valence-approach’ factor encompassing perceived attractiveness, healthiness, valence, and approach tendencies, and (2) a ‘safeness’ factor, entailing judgments of HIV risk, trustworthiness, and responsibility. These findings suggest that HIV risk ratings systematically relate to cardinal features of a high-risk HIV stereotype. Furthermore, event-related brain potential recordings revealed neural correlates of first impressions about HIV risk. Target persons perceived as risky elicited a differential brain response in a time window from 220–340 ms and an increased late positive potential in a time window from 350–700 ms compared to those perceived as safe. These data suggest that impressions about HIV risk can be formed in a split second and despite a lack of information about the actual risk profile. Findings of neural correlates of risk impressions and their relationship to key features of the HIV risk stereotype are discussed in the context of the ‘risk as feelings’ theory.

Simplicity itself.

I have to pass on this brief essay by one of my heroes, Thomas Metzinger:

Elegance is more than an aesthetic quality, or some ephemeral sort of uplifting feeling we experience in deeper forms of intuitive understanding. Elegance is formal beauty. And formal beauty as a philosophical principle is one of the most dangerous, subversive ideas humanity has discovered: it is the virtue of theoretical simplicity. Its destructive force is greater than Darwin's algorithm or that of any other single scientific explanation, because it shows us what the depth of an explanation is.

Elegance as theoretical simplicity comes in many different forms. Everybody knows Occam's razor, the ontological principle of parsimony: Entities are not to be multiplied beyond necessity. William of Occam gave us a metaphysical principle for choosing between competing theories: All other things being equal, it is rational to always prefer the theory that makes fewer ontological assumptions about the kinds of entities that really exist (souls, life forces, abstract objects, or an absolute frame of reference like electromagnetic ether). We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances—Isaac Newton formulated this as the First Rule of Reasoning in Philosophy, in his Principia Mathematica. Throw out everything that is explanatorily idle, and then shift the burden of proof to the proponent of a less simple theory. In Albert Einstein's words: The grand aim of all science … is to cover the greatest possible number of empirical facts by logical deductions from the smallest possible number of hypotheses or axioms.

Of course, in today's technical debates new questions have emerged: Why do metaphysics at all? Isn't it simply the number of free, adjustable parameters in competing hypotheses what we should measure? Is it not syntactic simplicity that captures elegance best, say, the number fundamental abstractions and guiding principles a theory makes use of? Or will the true criterion for elegance ultimately be found in statistics, in selecting the best model for a set of data points while optimally balancing parsimony with the "goodness of fit" of a suitable curve? And, of course, for Occam-style ontological simplicity the BIG question always remains: Why should a parsimonious theory more likely be true? Ultimately, isn't all of this rooted in a deeply hidden belief that God must have created a beautiful universe?

I find it fascinating to see how the original insight has kept its force over the centuries. The very idea of simplicity itself, applied as a metatheoretical principle, has demonstrated great power—the subversive power of reason and reductive explanation. The formal beauty of theoretical simplicity is deadly and creative at the same time. It destroys superfluous assumptions whose falsity we just cannot bring ourselves to believe, whereas truly elegant explanations always give birth to an entirely new way of looking at the world. What I would really like to know is this: Can the fundamental insight—the destructive, creative virtue of simplicity—be transposed from the realm of scientific explanation into culture or onto the level of conscious experience? What kind of formal simplicity would make our culture a deeper, more beautiful culture? And what is an elegant mind?

Our Thrifty Brains.

Andy Clark has done a piece that is really worth reading in the Stone, a New York Times forum for contemporary philosophers. (And, check out the video below):

Might the miserly use of neural resources be one of the essential keys to understanding how brains make sense of the world? Some recent work in computational and cognitive neuroscience suggests that it is indeed the frugal use of our native neural capacity (the inventive use of restricted “neural bandwidth,” if you will) that explains how brains like ours so elegantly make sense of noisy and ambiguous sensory input. That same story suggests, intriguingly, that perception, understanding and imagination, which we might intuitively consider to be three distinct chunks of our mental machinery, are inextricably tied together as simultaneous results of a single underlying strategy known as “predictive coding.” This strategy saves on bandwidth using (who would have guessed it?) one of the many technical wheezes that enable us to economically store and transmit pictures, sounds and videos using formats such as JPEG and MP3.

...perception may best be seen as what has sometimes been described as a process of “controlled hallucination” ...in which we (or rather, various parts of our brains) try to predict what is out there, using the incoming signal more as a means of tuning and nuancing the predictions rather than as a rich (and bandwidth-costly) encoding of the state of the world.

The basic effect hereabouts is neatly illustrated by a simple but striking demonstration (used by the neuroscientist Richard Gregory back in the 1970’s to make this very point) known as “the hollow face illusion.” This is a well-known illusion in which an ordinary face mask viewed from the back can appear strikingly convex. That is, it looks (from the back) to be shaped like a real face, with the nose sticking outward rather than having a concave nose cavity. Just about any hollow face mask will produce some version of this powerful illusion, and there are many examples on the Web, like this one:

A simple way to attentuate emotional arousal?

I just came across these interesting observations of Herwig et al.. They show that simply using self referential reflection (i.e., using mindfullness) to make an emotional state aware can attenuate amygdala activation and emotional arousal:

The regulation of emotions is an ongoing internal process and often a challenge. Current related neural models concern the intended control of reactions towards external events, mediated by prefrontal cortex regions upon basal emotion processing as in the amygdala. Cognitive strategies to regulate emotions in the context of affective disorders or stress reduction, increasingly applied in clinical practice, are also related to mindfulness techniques. We questioned their effects on neural emotion processing and investigated brain activity during purely internal mental self-referential processes of making current emotions and self-related cognitions aware. Thirty healthy subjects performed a task comprising periods of cognitive self-reflection, of introspection for actual own emotions and feelings, and of a neutral condition, while they were scanned with functional magnetic resonance imaging. Brain activations of twenty-seven subjects during emotion-introspection and self-reflection, and also a conjunction of both, were compared with the neutral condition. The conditions of self-reflection and emotion-introspection showed distinguishable activations in medial and ventrolateral prefrontal areas, in parietal regions and in the amygdala. Notably, amygdala activity decreased during emotion-introspection and increased compared to ‘neutral’ during self-reflection. The results indicate that already the self-referential mental state of making the actual emotional state aware is capable of attenuating emotional arousal. This extends current theories of emotion regulation and has implications for the application of mindfulness techniques as a component of psychotherapeutic strategies in affective disorders and also for possible everyday emotion regulation.

You think, therefore I am.

I pass on this contribution from Rose and Markus as their answer to this year's annual question from Edge.org (What is your favorite deep, elegant, or beautiful explanation?):

"I think, therefore I am." Cogito ergo sum. Remember this elegant and deep idea from René Descartes' Principles of Philosophy? The fact that a person is contemplating whether she exists, Descartes argued, is proof that she, indeed, actually does exist. With this single statement, Descartes knit together two central ideas of Western philosophy: 1) thinking is powerful, and 2) individuals play a big role in creating their own I's—that is, their psyches, minds, souls, or selves.

Most of us learn "the cogito" at some point during our formal education. Yet far fewer of us study an equally deep and elegant idea from social psychology: Other people's thinking likewise powerfully shapes the I's that we are. Indeed, in many situations, other people's thinking has a bigger impact on our own thoughts, feelings, and actions than do the thoughts we conjure while philosophizing alone.

In other words, much of the time, "You think, therefore I am." For better and for worse.

An everyday instance of how your thinking affects other people's being is the Pygmalion effect. Psychologists Robert Rosenthal and Lenore Jacobson captured this effect in a classic 1963 study. After giving an IQ test to elementary school students, the researchers told the teachers which students would be "academic spurters" because of their allegedly high IQs. In reality, these students' IQs were no higher than those of the "normal" students. At the end of the school year, the researchers found that the "spurters'" had attained better grades and higher IQs than the "normals." The reason? Teachers had expected more from the spurters, and thus given them more time, attention, and care. And the conclusion? Expect more from students, and get better results.

A less sanguine example of how much our thoughts affect other people's I's is stereotype threat. Stereotypes are clouds of attitudes, beliefs, and expectations that follow around a group of people. A stereotype in the air over African Americans is that they are bad at school. Women labor under the stereotype that they suck at math.

As social psychologist Claude Steele and others have demonstrated in hundreds of studies, when researchers conjure these stereotypes—even subtly, by, say, asking people to write down their race or gender before taking a test—students from the stereotyped groups score lower than the stereotype-free group. But when researchers do not mention other people's negative views, the stereotyped groups meet or even exceed their competition. The researchers show that students under stereotype threat are so anxious about confirming the stereotype that they choke on the test. With repeated failures, they seek their fortunes in other domains. In this tragic way, other people's thoughts deform the I's of promising students.

As the planet gets smaller and hotter, knowing that "You think, therefore I am" could help us more readily understand how we affect our neighbours and how our neighbours affect us. Not acknowledging how much we impact each other, in contrast, could lead us to repeat the same mistakes.

Cellular 'self eating' accounts for some beneficial effects of exercise.

Population studies suggest that exercise protects against diabetes, cancer, and age related diseases such as Alzheimer's. Work by Congcong He et al. has now shown that at least part of this effect is due to the increased "self-eating" (Autophagy) that cells must do to meet the energy demands of exercise. Autophagy recycles used or flawed membranes and internal cell structures by encircling its target material and then dumping it into a compartment that digests it. It has been shown in animal models to reduce diabetes, cancer, and neuro-degenerative diseases. The He et al. work documents that exercise induces autophagy in the skeletal muscles of mice, which in turn lowers glucose and insulin in the bloodstream. Mutant mice that don't induce more autophagy during exercise didn't show this effect. Further, the exercise induced reversal of diabetes induced by overfeeding mice was observed only the mice who showed a exercise induced increased autophagy. Here is the abstract with more details:

Exercise has beneficial effects on human health, including protection against metabolic disorders such as diabetes. However, the cellular mechanisms underlying these effects are incompletely understood. The lysosomal degradation pathway, autophagy, is an intracellular recycling system that functions during basal conditions in organelle and protein quality control. During stress, increased levels of autophagy permit cells to adapt to changing nutritional and energy demands through protein catabolism. Moreover, in animal models, autophagy protects against diseases such as cancer, neurodegenerative disorders, infections, inflammatory diseases, ageing and insulin resistance. Here we show that acute exercise induces autophagy in skeletal and cardiac muscle of fed mice. To investigate the role of exercise-mediated autophagy in vivo, we generated mutant mice that show normal levels of basal autophagy but are deficient in stimulus (exercise- or starvation)-induced autophagy. These mice (termed BCL2 AAA mice) contain knock-in mutations in BCL2 phosphorylation sites (Thr69Ala, Ser70Ala and Ser84Ala) that prevent stimulus-induced disruption of the BCL2–beclin-1 complex and autophagy activation. BCL2 AAA mice show decreased endurance and altered glucose metabolism during acute exercise, as well as impaired chronic exercise-mediated protection against high-fat-diet-induced glucose intolerance. Thus, exercise induces autophagy, BCL2 is a crucial regulator of exercise- (and starvation)-induced autophagy in vivo, and autophagy induction may contribute to the beneficial metabolic effects of exercise.