The ecology of religious beliefs

Botero et al. do a fascinating survey of 583 societies to show that religions with moralizing high gods that promote cooperation between humans are more prevalent among societies that inhabit poorer environments and are more prone to ecological duress:

Although ecological forces are known to shape the expression of sociality across a broad range of biological taxa, their role in shaping human behavior is currently disputed. Both comparative and experimental evidence indicate that beliefs in moralizing high gods promote cooperation among humans, a behavioral attribute known to correlate with environmental harshness in nonhuman animals. Here we combine fine-grained bioclimatic data with the latest statistical tools from ecology and the social sciences to evaluate the potential effects of environmental forces, language history, and culture on the global distribution of belief in moralizing high gods (n = 583 societies). After simultaneously accounting for potential nonindependence among societies because of shared ancestry and cultural diffusion, we find that these beliefs are more prevalent among societies that inhabit poorer environments and are more prone to ecological duress. In addition, we find that these beliefs are more likely in politically complex societies that recognize rights to movable property. Overall, our multimodel inference approach predicts the global distribution of beliefs in moralizing high gods with an accuracy of 91%, and estimates the relative importance of different potential mechanisms by which this spatial pattern may have arisen. The emerging picture is neither one of pure cultural transmission nor of simple ecological determinism, but rather a complex mixture of social, cultural, and environmental influences. Our methods and findings provide a blueprint for how the increasing wealth of ecological, linguistic, and historical data can be leveraged to understand the forces that have shaped the behavior of our own species.

E.O. Wilson and "The Meaning of Human Existence"

I've just read through E.O. Wilson's new and admirably brief and terse book (~200 pages) that gives a distillation of his previous writings on our human condition, and in particular the relationship between the sciences and the humanities. I pass on here a few clips from the first section of the book, but start with his statement in the final section where he gives his version of what the meaning of human existence is. (It conforms to my own opinion that experiencing ourselves as part of biological evolution suffices as a complete spiritual path.)

So, what is the meaning of human existence? I suggest that it is the epic of the species, begun in biological evolution and prehistory, passed into recorded history, and urgently now, day by day, faster and faster into the indefinite future, it is also what we will choose to become.

From Section I "The Reason We Exist":

In ordinary usage the word “meaning” implies intention, intention implies design, and design implies a designer. Any entity, any process, or definition of any word itself is put into play as a result of an intended consequence in the mind of the designer. This is the heart of the philosophical worldview of organized religions, and in particular their creation stories. Humanity, it assumes, exists for a purpose. Individuals have a purpose in being on Earth. Both humanity and individuals have meaning.

There is a second, broader way the word “meaning” is used and a very different worldview implied. It is that the accidents of history, not the intentions of a designer, are the source of meaning. There is no advance design, but instead overlapping networks of physical cause and effect. The unfolding of history is obedient only to the general laws of the Universe. Each event is random yet alters the probability of later events. During organic evolution, for example, the origin of one adaptation by natural selection makes the origin of certain other adaptations more likely. This concept of meaning, insofar as it illuminates humanity and the rest of life, is the worldview of science.

We are about to abandon natural selection , the process that created us, in order to direct our own evolution by volitional selection— the process of redesigning our biology and human nature as we wish them to be.

Humanity, I argue, arose entirely on its own through an accumulated series of events during evolution. We are not predestined to reach any goal, nor are we answerable to any power but our own. Only wisdom based on self-understanding, not piety, will save us.

...the grand master is multilevel selection . This formulation recognizes two levels at which natural selection operates: individual selection based on competition and cooperation among members of the same group, and group selection, which arises from competition and cooperation between groups. Group selection can occur through violent conflict or by competition between groups in the finding and harvesting of new resources.

Probably ... during the habiline period, a conflict ensued between individual-level selection, with individuals competing with other individuals in the same group, on the one side, and group-level selection , with competition among groups, on the other. The latter force promoted altruism and cooperation among all the group members. It led to innate group-wide morality and a sense of conscience and honor. The competition between the two forces can be succinctly expressed as follows: Within groups selfish individuals beat altruistic individuals, but groups of altruists beat groups of selfish individuals. Or, risking oversimplification, individual selection promoted sin, while group selection promoted virtue.

So it came to pass that humans are forever conflicted by their prehistory of multilevel selection. They are suspended in unstable and constantly changing positions between the two extreme forces that created us. We are unlikely to yield completely to either force as the ideal solution to our social and political turmoil. To give in completely to the instinctual urgings born from individual selection would be to dissolve society. At the opposite extreme, to surrender to the urgings from group selection would turn us into angelic robots— the outsized equivalents of ants.

Varieties of poverty - money, time, and bandwidth

We usually think of money when the word poverty is employed. But, just like getting caught in a high interest loan cycle, we can get in trouble by borrowing too much time, having a list of deadlines we continually fall behind on, forcing us to focus on the immediate next deadline, just like the next loan payment due. Konnikova points to the consequence of situations like these, bandwidth poverty:

If I’m focused on the immediate deadline, I don’t have the cognitive resources to spend on mundane tasks or later deadlines. If I’m short on money, I can’t stop thinking about today’s expenses — never mind those in the future. In both cases, I end up making decisions that leave me worse off because I lack the ability to focus properly on anything other than what’s staring me in the face right now, at this exact moment... 

She quotes a Princeton psychologist:

Under scarcity, you devote a lot of resources to the thing you’re lacking...When people are juggling time, they are doing something very similar to when they’re juggling finances. It is all scarcity juggling. You borrow from tomorrow, and tomorrow you have less time than you have today, and tomorrow becomes more costly. It’s a very costly loan.

Further clips:

When you get overloaded and you feel this deadline is overwhelming, you can say, I’ll take a vacation, I’ll focus on work-life balance...Poor people can’t say, ‘I’ll take a vacation from being poor.’ It’s the same mental process, but a different feedback loop.The poor are under a deadline that never lifts, pressure that can’t be relieved. If I am poor, I work or I churn until decisions like buying lottery tickets begin to seem like attractive alternatives. I lack the time to calculate the odds and think of alternative uses for my money...the mental bandwidth tax is powerful enough to make the overall problem run deeper. The poor... are so taxed they don’t even realize they have a problem...AND of course how much money you have affects how much time you have. If you keep busyness constant, the rich have it much easier...they can buy nannies and drivers and lawyers and the like. It’s easy to give yourself time if you have money.

If poverty is about time and mental bandwidth as well as money, how does this change how we combat its effects? When we think about programs for the poor, we don’t ever think, hey, let’s give them programs that don’t use a lot of bandwidth...Instead, we fault people for failing to sign up for programs that are ostensibly available, even though we don’t factor in the time and cognitive capacity they need to get past even the first step...Take something like the Fafsa” — the Free Application for Federal Student Aid — Why is pickup for the low-income families less than 30 percent? People are already overwhelmed, and you go and give them an incredibly complicated form...One study found that if you offer help with filling out the Fafsa form, pickup goes up significantly.

My iPad is masturbating!

As I have read the New York Times or Kindle Apps on my iPad over the past few weeks, the tablet has seemed to take on a mind of its own, opening articles or turning pages when I haven't touched it. Going by a techie store I am asked whether the screen has ever been broken and replaced, and indeed, this happened several months ago. It appears that if the job isn't done properly, or the screen is a poor quality one, it can start spontaneous touching or stroking in the absence of a human finger. To turn pages I am now gingerly stroking parts of the screen that don't seem to get its g-spots excited..... (I don't want to buy a new iPad because I am waiting for the larger one to come out, it will be more useful for displaying musical scores.)

The peripheral immune system and stress susceptibility.

Using a social stress model in mice, Hoades et al. find preexisting individual differences in the sensitivity of the peripheral immune system that predict and promote vulnerability to social stress. Finding that the emotional response to stress can be generated or blocked outside the brain suggest a new route for treating stress disorders, perhaps by controlling the peripheral level of the cytokine IL-6.

Significance

Depression and anxiety have been linked to increased inflammation. However, we do not know if inflammatory status predates onset of disease or whether it contributes to depression symptomatology. We report preexisting individual differences in the peripheral immune system that predict and promote stress susceptibility. Replacing a stress-naive animal’s peripheral immune system with that of a stressed animal increases susceptibility to social stress including repeated social defeat stress (RSDS) and witness defeat (a purely emotional form of social stress). Depleting the cytokine IL-6 from the whole body or just from leukocytes promotes resilience, as does sequestering IL-6 outside of the brain. These studies demonstrate that the emotional response to stress can be generated or blocked in the periphery, and offer a potential new form of treatment for stress disorders.

Abstract

Depression and anxiety disorders are associated with increased release of peripheral cytokines; however, their functional relevance remains unknown. Using a social stress model in mice, we find preexisting individual differences in the sensitivity of the peripheral immune system that predict and promote vulnerability to social stress. Cytokine profiles were obtained 20 min after the first social stress exposure. Of the cytokines regulated by stress, IL-6 was most highly up-regulated only in mice that ultimately developed a susceptible behavioral phenotype following a subsequent chronic stress, and levels remained elevated for at least 1 mo. We confirmed a similar elevation of serum IL-6 in two separate cohorts of patients with treatment-resistant major depressive disorder. Before any physical contact in mice, we observed individual differences in IL-6 levels from ex vivo stimulated leukocytes that predict susceptibility versus resilience to a subsequent stressor. To shift the sensitivity of the peripheral immune system to a pro- or antidepressant state, bone marrow (BM) chimeras were generated by transplanting hematopoietic progenitor cells from stress-susceptible mice releasing high IL-6 or from IL-6 knockout (IL-6−/−) mice. Stress-susceptible BM chimeras exhibited increased social avoidance behavior after exposure to either subthreshold repeated social defeat stress (RSDS) or a purely emotional stressor termed witness defeat. IL-6−/− BM chimeric and IL-6−/− mice, as well as those treated with a systemic IL-6 monoclonal antibody, were resilient to social stress. These data establish that preexisting differences in stress-responsive IL-6 release from BM-derived leukocytes functionally contribute to social stress-induced behavioral abnormalities.

Does exercise really make us smarter?

A NYTimes Well piece by Gretchen Reynolds points to an interesting study by Stothart et al., who decided to address a basic deficiency in most studies of the effects of aerobic training on cognition, they don't control for a possible placebo effect. If we expect to be smarter after training, our brains might just respond correspondingly. Stothart et al. found that people queried in an online survey expected a muscle stretching and toning program to have a greater effect on measures of thinking than a regular walking program. In actual experiments, stretching and toning regimens generally have been shown to have little if any impact on people’s cognitive skills. Walking, on the other hand, seems to substantially improve thinking ability. This lack of correlation between expectations and actual outcome suggests that a placebo effect does not explain the improved cognition observed after exercise.

The usefulness of spite.

Angier reviews a number of studies suggesting that the evolution of human cooperation can be assisted by spite, a certain degree of "altruistic" punishment, when some individuals are willing to punish rule breakers even when the infraction does not directly affect them. From Forber and Smead:

The presence of apparently irrational fair play in the ultimatum game remains a focal point for studies in the evolution of social behaviour. We investigate the role of negative assortment in the evolution of fair play in the ultimatum game. Spite-social behaviour that inflicts harm with no direct benefit to the actor-can evolve when it is disproportionally directed at individuals playing different strategies. The introduction of negative assortment alters the dynamics in a way that increases the chance fairness evolves, but at a cost: spite also evolves. Fairness is usually linked to cooperation and prosocial behaviour, but this study shows that it may have evolutionary links to harmful antisocial behaviour.

And, from Marlowe et al.:

We analyse generosity, second-party ('spiteful') punishment (2PP), and third-party ('altruistic') punishment (3PP) in a cross-cultural experimental economics project. We show that smaller societies are less generous in the Dictator Game but no less prone to 2PP in the Ultimatum Game. We might assume people everywhere would be more willing to punish someone who hurt them directly (2PP) than someone who hurt an anonymous third person (3PP). While this is true of small societies, people in large societies are actually more likely to engage in 3PP than 2PP. Strong reciprocity, including generous offers and 3PP, exists mostly in large, complex societies that face numerous challenging collective action problems. We argue that 'spiteful' 2PP, motivated by the basic emotion of anger, is more universal than 3PP and sufficient to explain the origins of human cooperation.

Brain's inflammatory response may contribute to brain disorders.

This post is just a pointer to a press release from the Society for Neuroscience meetings in Washington, DC. It outlines several studies on the link between brain inflammation and the progression of many common brain illnesses and disorders, suggesting possible targets for future treatments.

In older people, moderate alcohol intake improves memory.

Articles like this work from Downer et al. make me worry less about the possible deleterious effects of the happy hour cocktail that is part of my daily ritual. Several studies have shown that light and moderate alcohol consumption during late life is associated with higher cognitive functioning among older adults and a decreased risk of dementia, and they now document relevant correlations with the volume of the hippocampus, which is important in memory. Their abstract, slightly edited:

This study utilized data from the Framingham Heart Study Offspring Cohort to examine the relationship between midlife and late-life alcohol consumption, cognitive functioning, and regional brain volumes among older adults without dementia or a history of abusing alcohol. The results from multiple linear regression models indicate that late life, but not midlife, alcohol consumption status is associated with episodic memory and hippocampal volume. Compared to late life abstainers, moderate consumers had larger hippocampal volume, and light consumers had higher episodic memory. The differences in episodic memory according to late life alcohol consumption status were no longer significant when hippocampal volume was included in the regression model (This suggests that the observed relationship between alcohol consumption and episodic memory and alcohol consumption during old age may be due to larger hippocampal volume.) The findings from this study provide new evidence that hippocampal volume may contribute to the observed differences in episodic memory among older adults and late life alcohol consumption status.

The authors note that findings from animal studies suggest that moderate alcohol consumption may contribute to preserved hippocampal volume by promoting the generation of new neurons in the hippocampus. In addition, exposing the brain to moderate amounts of alcohol may increase the release of acetylcholine and other neurotransmitters that are involved in cognitive functioning.

How to dampen that urge to buy.

A brief post appropriate to the season: Seeing DeSteno's recent OpEd piece in the NYTimes make me think this is a relevant time to point back to my June post on his work. His OpEd piece is trying to broadcast to a larger audience possibly revving up for Black Friday's shopping madness. Exercising self-control to resist impulse buying takes a lot of energy, which is easily depleted. The DeSteno et al. experiments show that there is an easier way: cultivating the emotion of gratitude enhances patience and self-control. They asked asked 75 people to recall and describe in writing one of three events: a time they felt grateful, a time they felt amused or a typical day. Those describing a time of feeling greatful were twice as likely to be able to defer an immediate gratification in favor of a longer term reward. The take home message is that feeling grateful can sometimes temporarily enhance self-control by decreasing desires for immediate gratification.  (And, guess who just ordered a larger flat screen TV from Amazon's Black Friday sale, being delivered this Friday....)

Can brain science be dangerous?

Mindblog has done a number of posts on long terms brain and behavioral effects of early adverse environments. This OpEd piece by Anna North on the possible uses and misuses of such information is well worth a read.

How our prefrontal cortex explores and exploits options.

Hare describes work by Donoso et al:

Inferring the best response from a large range of possible actions frequently involves difficult computations that the brain is unlikely to perform rapidly. Nevertheless, humans often do well in such situations. Donoso et al. demonstrate that a computational model designed to integrate reward learning with probabilistic inference (i.e., computing the odds) and a form of hypothesis testing can approximate the optimal solution in a neurobiologically plausible manner. Moreover, the model provides a good fit to human behavior and, as seen by functional magnetic resonance imaging (fMRI), is represented in the activity patterns of specific prefrontal and striatal brain regions. 

Figure - Reasoning regions - Activity in specific brain regions tracks the reliability of executed strategies (medial prefrontal cortex), alternative strategies (frontopolar cortex, not shown), the need to explore new strategies (dorsal anterior cingulate cortex), and the confimation of strategies as valid (ventral striatum).

The Donoso et al abstract:

The prefrontal cortex (PFC) subserves reasoning in the service of adaptive behavior. Little is known, however, about the architecture of reasoning processes in the PFC. Using computational modeling and neuroimaging, we show here that the human PFC has two concurrent inferential tracks: (i) one from ventromedial to dorsomedial PFC regions that makes probabilistic inferences about the reliability of the ongoing behavioral strategy and arbitrates between adjusting this strategy versus exploring new ones from long-term memory, and (ii) another from polar to lateral PFC regions that makes probabilistic inferences about the reliability of two or three alternative strategies and arbitrates between exploring new strategies versus exploiting these alternative ones. The two tracks interact and, along with the striatum, realize hypothesis testing for accepting versus rejecting newly created strategies.

Art in a whiskey glass, the physics explained.

Here's a random bit that provides a tonic for the day. Ernie Button, a photographer in Phoenix, started taking pictures of the interesting patterns he noticed forming as the last bit of his single malt aged Scotch whiskey dried in the glass he had used.

The article describes the findings of some physicists he contacted, who determined what was going on.

Wealth is especially bad for the wealthy.

Michael Lewis reviews Darrell West's new book "Billionaires: Reflections on the Upper Crust" in The New Republic. The review starts with a marvellous story about breakfast at a tennis camp for children of the East Coast elite:

Jack Kenney’s assault on teenaged American inequality began at breakfast the first morning...On each table were small boxes of cereal, enough for each kid to have one box, but not enough that everyone could have the brand of cereal he wanted. There were Fruit Loops and Cheerios, but also more than a few boxes of the deadly dark bran stuff consumed willingly only by old people suffering from constipation...By the third morning, it was clear that, in the race to the Fruit Loops, some kids had a natural advantage...Some kids would always get the Fruit Loops, and others would always get the laxative. Life was now officially unfair.

After that third breakfast, Kenney called an assembly, saying...“You all live in important places surrounded by important people...When I’m in the big city, I never understand the faces of the people, especially the people who want to be successful. They look so worried! So unsatisfied!...In the city you see people grasping, grasping, grasping. Taking, taking, taking. And it must be so hard! To be always grasping-grasping, and taking-taking. But no matter how much they have, they never have enough. They’re still worried. About what they don’t have. They’re always empty.”

“You have a choice. You don’t realize it, but you have a choice. You can be a giver or you can be a taker. You can get filled up or empty. You make that choice every day. You make that choice at breakfast when you rush to grab the cereal you want so others can’t have what they want.” And then he moved on to why no one should ever hit a two-handed backhand—while every kid on the hill squirmed and reddened and glanced at each other, wondering if everyone else realized what an asshole he’d been.

On the fourth morning, no one ate the Fruit Loops. Kids were thrusting the colorful boxes at each other and leaping on the constipation cereal like war heroes jumping on hand grenades. In a stroke, the texture of life in this tennis camp had changed, from a chapter out of Lord of the Flies to the feeling between the lines of Walden.

Lewis follows with a discussion of the increase in wealth inequality, and whether rich people are significantly determining political outcomes. The evidence is not clear.

If these billionaires are seeking, as a class, to minimize the sums they return to society, they are not doing a very good job of it. But of course they aren’t seeking anything, as a class: it’s not even clear they can agree on what their collective interests are. The second richest American billionaire, Warren Buffett, has been quite vocal about his desire for higher tax rates on the rich. The single biggest donor to political campaigns just now is Tom Steyer, a Democrat with a passion for climate change. And for every rich person who sets off on a jag to carve California into seven states, or to defeat Barack Obama, there are many more who have no interest in politics at all except perhaps, in a general way, to prevent them from touching their lives. Rich people, in my experience, don’t want to change the world. The world as it is suits them nicely.

Lewis cites Dacher Keltner's work, which has been the subject of several mindblog posts (see here and here).

What is clear about rich people and their money...is how it changes them...Keltner and his colleague Paul Piff installed note-takers and cameras at city street intersections with four-way stop signs. The people driving expensive cars were four times more likely to cut in front of other drivers than drivers of cheap cars. The researchers then followed the drivers to the city’s cross walks and positioned themselves as pedestrians, waiting to cross the street. The drivers in the cheap cars all respected the pedestrians’ right of way. The drivers in the expensive cars ignored the pedestrians 46.2 percent of the time...the Berkeley researchers invited a cross section of the population into their lab and marched them through a series of tasks. Upon leaving the laboratory testing room the subjects passed a big jar of candy. The richer the person, the more likely he was to reach in and take candy from the jar—and ignore the big sign on the jar that said the candy was for the children who passed through the department.

Other studies show that a person, as he grows richer, becomes more likely to violate the rules of the road, to cheat, shoplift, and give less to charity.

A UCLA neuroscientist named Keely Muscatell has published an interesting paper showing that wealth quiets the nerves in the brain associated with empathy: if you show rich people and poor people pictures of kids with cancer, the poor people’s brains exhibit a great deal more activity than the rich people’s...The problem is caused by the inequality itself: it triggers a chemical reaction in the privileged few. It tilts their brains. It causes them to be less likely to care about anyone but themselves or to experience the moral sentiments needed to be a decent citizen...Or even a happy one...The evidence overwhelmingly suggests that money, above a certain modest sum, does not have the power to buy happiness, and yet even very rich people continue to believe that it does: the happiness will come from the money they don’t yet have. To the general rule that money, above a certain low level, cannot buy happiness there is one exception...While spending money upon oneself does nothing for one’s happiness,spending it on others increases happiness.

(By the way, I dug up the Muscatell paper, which does fMRI studies to show that individuals lower in social status are more likely to engage neural circuitry involved in thinking about others' thought and feelings.)

If the Harvard Business School is now making a home for research exposing the folly of a life devoted to endless material ambition, something in the world has changed—or is changing. And I think it is: there is a growing awareness that the yawning gap between rich and poor is no longer a matter of simple justice but also the enemy of economic success and human happiness. It’s not just bad for the poor. It’s also bad for the rich. It’s funny, when you think about it, how many rich people don’t know this. But they are not idiots; they can learn. Many even possess the self-awareness to correct for whatever tricks their brain chemicals seek to play on them; some of them already do it. When you control a lot more than your share of the Fruit Loops, there really isn’t much doubt about what you should do with them, for your own good. You just need to be reminded, loudly and often.

Genes that turned wildcats into kitty cats.

Reaction of my Abyssinian cat, Melvin, to finding that his genome had been sequenced.

David Grimm summarizes work by Montague et al., who sequenced the genome of a female Abyssinian cat, a domestic breed, and compared it with genome assemblies of six other domestic breeds, two wild cat species, and four other mammals to find genomic differences that might underlie cat biology and domestication. The authors found that, compared with wild cat genomes, domestic cat genomes displayed evidence of natural selection in genes linked to memory, fear-conditioning behavior, and stimulus-reward learning, suggesting that the genetic changes may underlie the evolution of tameness.

Cooperating with the future - how to sustain resources.

From Hauser et al., an experiment showing that if resource extraction decision are made by vote rather than individually, the resource can be sustained. Voting is effective for two reasons. First, it allows a majority of cooperators to restrain defectors. Second, it reassures conditional cooperators that their efforts are not futile. Voting, however, only promotes sustainability if it is binding for all involved. A summary of this work by Kerri Smith has a nice explanatory video. Here is the abstract:

Overexploitation of renewable resources today has a high cost on the welfare of future generations. Unlike in other public goods games, however, future generations cannot reciprocate actions made today. What mechanisms can maintain cooperation with the future? To answer this question, we devise a new experimental paradigm, the ‘Intergenerational Goods Game’. A line-up of successive groups (generations) can each either extract a resource to exhaustion or leave something for the next group. Exhausting the resource maximizes the payoff for the present generation, but leaves all future generations empty-handed. Here we show that the resource is almost always destroyed if extraction decisions are made individually. This failure to cooperate with the future is driven primarily by a minority of individuals who extract far more than what is sustainable. In contrast, when extractions are democratically decided by vote, the resource is consistently sustained. Voting is effective for two reasons. First, it allows a majority of cooperators to restrain defectors. Second, it reassures conditional cooperators16 that their efforts are not futile. Voting, however, only promotes sustainability if it is binding for all involved. Our results have implications for policy interventions designed to sustain intergenerational public goods.

Humor and Health

I want to point to this item by Jennifer Gibson that reminds me how useful it might be for me to "lighten up" just a little bit, try to get a daily laugh. Her article, with 11 article citations at its end, points to studies that suggest laughter, humor, or mirth improve short term memory and learning ability, lower stress hormone levels, improve immune function, lower blood pressure, etc.

Chemicals that delay or reverse effects of aging.

I scan for articles on aging in my wanderings through journals and pass on the following two, on chemical compounds that delay or reverse the effects of aging:

Mowia et al. suggest the prospect of an anti-aging pill that might extend life span and delay onset of age-related diseases. They fed mice a synthetic activator of SIRT1 (NAD-dependent deactylase sirtuin 1) from 6 months of age for the rest of their (∼3-year) life span. The treated mice had 5% and 10% increases in maximum and mean life span, respectively. They also resisted many problems associated with human aging. Here's the abstract:

Increased expression of SIRT1 extends the lifespan of lower organisms and delays the onset of age-related diseases in mammals. Here, we show that SRT2104, a synthetic small molecule activator of SIRT1, extends both mean and maximal lifespan of mice fed a standard diet. This is accompanied by improvements in health, including enhanced motor coordination, performance, bone mineral density, and insulin sensitivity associated with higher mitochondrial content and decreased inflammation. Short-term SRT2104 treatment preserves bone and muscle mass in an experimental model of atrophy. These results demonstrate it is possible to design a small molecule that can slow aging and delay multiple age-related diseases in mammals, supporting the therapeutic potential of SIRT1 activators in humans.

Gervain et al. find an instance of restoring brain plasticity characteristic of early life to an adult brain with valporate, a very simple organic structure (enter 'valporate' in google images to see the structure):

Absolute pitch, the ability to identify or produce the pitch of a sound without a reference point, has a critical period, i.e., it can only be acquired early in life. However, research has shown that histone-deacetylase inhibitors (HDAC inhibitors) enable adult mice to establish perceptual preferences that are otherwise impossible to acquire after youth. In humans, we found that adult men who took valproate (VPA) (a HDAC inhibitor) learned to identify pitch significantly better than those taking placebo—evidence that VPA facilitated critical-period learning in the adult human brain. Importantly, this result was not due to a general change in cognitive function, but rather a specific effect on a sensory task associated with a critical-period.

Big data in Neuroscience

I want to pass on an interesting graphic from a piece by Sejnowski, Churchland, and Movshon that introduces a "Focus on big data" series of articles in the November issue of Nature Neuroscience, on the challenges presented by the overwhelming flood of data on the brain being generated by new recording and visualization techniques, from the ultra-micro to the macro scale. (I'm afraid on looking at the whole ensemble of articles I quickly start seeing only gibble-gabble as my-eyes-glaze-over...) The graphic illustrates the spatial and temporal domain, and the increase in the number, of techniques that have appeared since 1988.

Each colored region represents the useful domain of spatial and temporal resolution for one method available for the study of the brain. Open regions represent measurement techniques; filled regions, perturbation techniques. Inset, a cartoon rendition of the methods available in 1988, notable for the large gaps where no useful method existed. The regions allocated to each domain are somewhat arbitrary and represent our own estimates. EEG, electroencephalography; MEG, magnetoencephalography; PET, positron emission tomography; VSD, voltage-sensitive dye; TMS, transcranial magnetic stimulation; 2-DG, 2-deoxyglucose.

The internet and the mind

This is a brief post to point to Jacob Silverman's quick reviews of four books that consider how enhanced connectivity might be altering us.