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.
Friday, November 28, 2014
Thursday, November 27, 2014
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.
Wednesday, November 26, 2014
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....)
Tuesday, November 25, 2014
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.
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.
Monday, November 24, 2014
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.
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.
Friday, November 21, 2014
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.
Thursday, November 20, 2014
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.
Wednesday, November 19, 2014
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.
Tuesday, November 18, 2014
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.
Monday, November 17, 2014
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.
Sunday, November 16, 2014
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.
Saturday, November 15, 2014
Maybe a hit of NDMA, the party drug ecstasy (not to be confused with the methamphetamine of crystal meth, which is another derivative of the core amphetamine structure), would be good for the wingnuts in both political parties! From Hysek et al.:
3,4-Methylenedioxymethamphetamine (MDMA, ‘ecstasy’) releases serotonin and norepinephrine. MDMA is reported to produce empathogenic and prosocial feelings. It is unknown whether MDMA in fact alters empathic concern and prosocial behavior. We investigated the acute effects of MDMA using the Multifaceted Empathy Test (MET), dynamic Face Emotion Recognition Task (FERT) and Social Value Orientation (SVO) test. We also assessed effects of MDMA on plasma levels of hormones involved in social behavior using a placebo-controlled, double-blind, random-order, cross-over design in 32 healthy volunteers (16 women). MDMA enhanced explicit and implicit emotional empathy in the MET and increased prosocial behavior in the SVO test in men. MDMA did not alter cognitive empathy in the MET but impaired the identification of negative emotions, including fearful, angry and sad faces, in the FERT, particularly in women. MDMA increased plasma levels of cortisol and prolactin, which are markers of serotonergic and noradrenergic activity, and of oxytocin, which has been associated with prosocial behavior. In summary, MDMA sex-specifically altered the recognition of emotions, emotional empathy and prosociality. These effects likely enhance sociability when MDMA is used recreationally and may be useful when MDMA is administered in conjunction with psychotherapy in patients with social dysfunction or post-traumatic stress disorder.
Friday, November 14, 2014
This post points to another of the articles in the Science special issue on aging. Lindenberger summarizes key features of human cognitive aging from the combined perspectives of life-span psychology and the cognitive neuroscience of aging, and notes a number of longitudinal studies that suggest that leading an intellectually challenging, physically active, and socially engaged life may mitigate losses and consolidate gains during cognitive aging. Here is a summary figure from the article:
Figure. An individual’s range of possible cognitive developmental trajectories from early to late adulthood.
The blue curve shows the most likely developmental path under normal circumstances. The fading of the background color indicates that more extreme paths are less likely. The functional threshold represents a level of functioning below which goal-directed action in the individual’s ecology will be severely compromised. The red curve represents the hope that changes in organism-environment interactions during adulthood move the individual onto a more positive trajectory. Beneficial changes may consist in the mitigation of risk factors, such as vascular conditions, metabolic syndrome, or chronic stress; the strengthening of enhancing factors, such as neuroplasticity; or both.
Thursday, November 13, 2014
I've done a post on Graziano's 'attention schema' theory of conscious, and thought I would pass on some clips from his recent exposition of the model in a NYTimes piece. In the title, and in the text below, a few qualifying phrases might have avoided the strong responses to Graziano in the letters to the editor that I also note below. I've added some qualifiers in brackets [ ]. For the inflammatory title "Are we really conscious?" what about adding [in the way we commonly suppose?].
...the argument here is that there is no subjective impression [in the way we commonly suppose]; there is only information in a data-processing device. When we look at a red apple, the brain computes information about color. It also computes information about the self and about a (physically incoherent) property of subjective experience. The brain’s cognitive machinery accesses that interlinked information and derives several conclusions: There is a self, a me; there is a red thing nearby; there is such a thing as subjective experience; and I have an experience of that red thing. Cognition is captive to those internal models. Such a brain would inescapably conclude it has subjective experience.
I concede that this approach is counterintuitive. One reason is that it seems to leave a gap in the logic: Why would the brain waste energy computing information about subjective awareness and attributing that property to itself, if the brain doesn’t in fact have this property?
This is where my own work comes in. In my lab at Princeton, my colleagues and I have been developing the “attention schema” theory of consciousness, which may explain why that computation is useful and would evolve in any complex brain. Here’s the gist of it:
Take again the case of color and wavelength. Wavelength is a real, physical phenomenon; color is the brain’s approximate, slightly incorrect model of it. In the attention schema theory, attention is the physical phenomenon and awareness is the brain’s approximate, slightly incorrect model of it. In neuroscience, attention is a process of enhancing some signals at the expense of others. It’s a way of focusing resources. Attention: a real, mechanistic phenomenon that can be programmed into a computer chip. Awareness: a cartoonish reconstruction of attention that is as physically inaccurate as the brain’s internal model of color.
In this theory, awareness is not an illusion. It’s a caricature. Something — attention — really does exist, and awareness is a distorted accounting of it.
One reason that the brain needs an approximate model of attention is that to be able to control something efficiently, a system needs at least a rough model of the thing to be controlled. Another reason is that to predict the behavior of other creatures, the brain needs to model their brain states, including their attention. This theory pulls together evidence from social neuroscience, attention research, control theory and elsewhere.
Almost all other theories of consciousness are rooted in our intuitions about awareness. Like the intuition that white light is pure [when it is in fact a spectrum of all colors], our intuitions about awareness come from information computed deep in the brain. But the brain computes models that are caricatures of real things. And as with color, so with consciousness: It’s best to be skeptical of intuition.The letters in response to the above take Graziano to task for "explaining consciousness away" when what he is trying to do is not discount our experience of awareness or selfhood, but make a description of the physical process that actually constitutes them, a description that is counter-intuitive, but I think more likely to be correct than anything I've see thus far.
Wednesday, November 12, 2014
Yau et al. find that a hormone secreted by fat cells during exercise alleviates depression-like behaviors in mice and boosts new nerve cell synthesis in the hippocampus. The hormone, or compounds that enhance its effectiveness, are potential antidepressant drugs. I copy below their significance section and the abstract with some of the chemical details.
This study unmasks a previously unidentified functional role of adiponectin (a hormone secreted by adipocytes) in modulating hippocampal neurogenesis and alleviating depression-like behaviors. To our knowledge, this is the first report showing that adiponectin may be an essential factor that mediates the antidepressant effects of physical exercise on the brain by adiponectin receptor 1-mediated activation of AMP-activated protein kinase. Our results reveal a possible mechanism by which exercise increases hippocampal neurogenesis and also suggest a promising therapeutic treatment for depression.Abstract
Adiponectin (ADN) is an adipocyte-secreted protein with insulin-sensitizing, antidiabetic, anti-inflammatory, and antiatherogenic properties. Evidence is also accumulating that ADN has neuroprotective activities, yet the underlying mechanism remains elusive. Here we show that ADN could pass through the blood–brain barrier, and elevating its levels in the brain increased cell proliferation and decreased depression-like behaviors. ADN deficiency did not reduce the basal hippocampal neurogenesis or neuronal differentiation but diminished the effectiveness of exercise in increasing hippocampal neurogenesis. Furthermore, exercise-induced reduction in depression-like behaviors was abrogated in ADN-deficient mice, and this impairment in ADN-deficient mice was accompanied by defective running-induced phosphorylation of AMP-activated protein kinase (AMPK) in the hippocampal tissue. In vitro analyses indicated that ADN itself could increase cell proliferation of both hippocampal progenitor cells and Neuro2a neuroblastoma cells. The neurogenic effects of ADN were mediated by the ADN receptor 1 (ADNR1), because siRNA targeting ADNR1, but not ADNR2, inhibited the capacity of ADN to enhance cell proliferation. These data suggest that adiponectin may play a significant role in mediating the effects of exercise on hippocampal neurogenesis and depression, possibly by activation of the ADNR1/AMPK signaling pathways, and also raise the possibility that adiponectin and its agonists may represent a promising therapeutic treatment for depression.
Tuesday, November 11, 2014
I'm continuing to clean out my queue of aging articles that have been languishing as potential posts...
Reynolds points to two studies. In one, Swedish researchers showed that a group of 68 year old couch potatoes who spent less time sitting and more time in an exercise program had longer telomere caps at the end of their DNA (the caps shorten with aging). The interesting finding was that this was related not to the exercise, but to simply not sitting down as much. A second article reviewed a large database of Canadian adults to find that longer amounts to time spent standing correlated with lower mortality rates.
Span does a review (linking to original articles) of work showing, for example that people who hold more positive views towards aging live 7.5 years longer on average than those who think negatively about aging, and recover more quickly from disabilities. Age stereotypes have a powerful effect, people become what they think. Thinking of older age as a time when one can feel capable, active, full of life, a time of wisdom, self-realization and satisfaction, is rather different from imagining it to be a time of becoming useless, helpless or devalued. A growing body of research shows that people with the latter attitudes are less likely to seek preventive medical care and die earlier, and more likely to suffer memory loss and poor physical functioning.
One interesting bit of work shows that subliminal intervention (flashing positive about aging on a screen so briefly that the brain registers them but they are not perceived) significantly strengthened positive age stereotypes and self-perceptions of age. The abstract:
Negative age stereotypes that older individuals assimilate from their culture predict detrimental outcomes, including worse physical function. We examined, for the first time, whether positive age stereotypes, presented subliminally across multiple sessions in the community, would lead to improved outcomes. Each of 100 older individuals (age = 61–99 years, M = 81) was randomly assigned to an implicit-positive-age-stereotype-intervention group, an explicit-positive-age-stereotype-intervention group, a combined implicit- and explicit-positive-age-stereotype-intervention group, or a control group. Interventions occurred at four 1-week intervals. The implicit intervention strengthened positive age stereotypes, which strengthened positive self-perceptions of aging, which, in turn, improved physical function. The improvement in these outcomes continued for 3 weeks after the last intervention session. Further, negative age stereotypes and negative self-perceptions of aging were weakened. For all outcomes, the implicit intervention’s impact was greater than the explicit intervention’s impact. The physical-function effect of the implicit intervention surpassed a previous study’s 6-month-exercise-intervention’s effect with participants of similar ages. The current study’s findings demonstrate the potential of directing implicit processes toward physical-function enhancement over time.
Monday, November 10, 2014
MindBlog has done numerous posts on our brains' default mode and executive control networks, with the idea usually being that activating the default network or mind wandering during an attention demanding task can impair performance. Spreng et al. now do a study showing that it also can improve performance if the mind wandering is congruent with the task itself. In this case the default and executive control networks appear to relate external goals and internal meaning:
Substantial neuroimaging evidence suggests that spontaneous engagement of the default network impairs performance on tasks requiring executive control. We investigated whether this impairment depends on the congruence between executive control demands and internal mentation. We hypothesized that activation of the default network might enhance performance on an executive control task if control processes engage long-term memory representations that are supported by the default network. Using fMRI, we scanned 36 healthy young adult humans on a novel two-back task requiring working memory for famous and anonymous faces. In this task, participants (1) matched anonymous faces interleaved with anonymous face, (2) matched anonymous faces interleaved with a famous face, or (3) matched a famous faces interleaved with an anonymous face. As predicted, we observed a facilitation effect when matching famous faces, compared with anonymous faces. We also observed greater activation of the default network during these famous face-matching trials. The results suggest that activation of the default network can contribute to task performance during an externally directed executive control task. Our findings provide evidence that successful activation of the default network in a contextually relevant manner facilitates goal-directed cognition.
Sunday, November 09, 2014
I pass on this fetching clutch of points on the usefulness of reading literature (rather than brief tweets, and blog posts like this) from Alain de Botton's School of Life, via Maria Popova's "Brain Pickings" (both are sites well worth checking out). Literature:
SAVES YOU TIME
It looks like it's wasting time, but literature is actually the ultimate time-saver – because it gives us access to a range of emotions and events that it would take you years, decades, millennia to try to experience directly. Literature is the greatest reality simulator – a machine that puts you through infinitely more situations than you can ever directly witness.
MAKES YOU NICER
Literature performs the basic magic of what things look like though someone else's point of view; it allows us to consider the consequences of our actions on others in a way we otherwise wouldn't; and it shows us examples of kindly, generous, sympathetic people.
Literature deeply stands opposed to the dominant value system – the one that rewards money and power. Writers are on the other side – they make us sympathetic to ideas and feelings that are of deep importance but can't afford airtime in a commercialized, status-conscious, and cynical world.
IS A CURE FOR LONELINESS
We're weirder than we like to admit. We often can't say what's really on our minds. But in books we find descriptions of who we genuinely are and what events, described with an honesty quite different from what ordinary conversation allows for. In the best books, it's as if the writer knows us better than we know ourselves – they find the words to describe the fragile, weird, special experiences of our inner lives... Writers open our hearts and minds, and give us maps to our own selves, so that we can travel in them more reliably and with less of a feeling of paranoia or persecution...
PREPARES YOU FOR FAILURE
All of our lives, one of our greatest fears is of failure, of messing up, of becoming, as the tabloids put it, "a loser." Every day, the media takes us into stories of failure. Interestingly, a lot of literature is also about failure – in one way or another, a great many novels, plays, poems are about people who messed up... Great books don't judge as harshly or as one-dimensionally as the media...