Our memory can be selectively rewritten during its reconsolidation.

Chan and LaPaglia make an interesting observation in humans that had previously only been reported in animal studies. We can mess with an existing declarative memory of an event after that memory has been reactivated, if during its reconsolidation we are presented with changes that target and change some details of the original memory. Reactivated memories are vulnerable only to interference that specifically targets the existing memories. This work provides yet another example of how eye witness testimony of the sort used in legal proceedings can become unreliable.

During the past decade, a large body of research has shown that memory traces can become labile upon retrieval and must be restabilized. Critically, interrupting this reconsolidation process can abolish a previously stable memory. Although a large number of studies have demonstrated this reconsolidation associated amnesia in nonhuman animals, the evidence for its occurrence in humans is far less compelling, especially with regard to declarative memory. In fact, reactivating a declarative memory often makes it more robust and less susceptible to subsequent disruptions. Here we show that existing declarative memories can be selectively impaired by using a noninvasive retrieval–relearning technique. In six experiments, we show that this reconsolidation-associated amnesia can be achieved 48 h after formation of the original memory, but only if relearning occurred soon after retrieval. Furthermore, the amnesic effect persists for at least 24 h, cannot be attributed solely to source confusion and is attainable only when relearning targets specific existing memories for impairment. These results demonstrate that human declarative memory can be selectively rewritten during reconsolidation.

Antonin Scalia Does Not Believe in Molecular Biology

Thanks to my son Jon for pointing this out to me.

Private behaviors from public records...

The exposure of the PRISM surveillance system by Edward Snowden gave me a sort of "So what else is new?" reaction... I thought we knew this unfortunate stuff was happening, particularly in view of numerous academic articles in the vein of the following from Kosinski et al.:

We show that easily accessible digital records of behavior, Facebook Likes, can be used to automatically and accurately predict a range of highly sensitive personal attributes including: sexual orientation, ethnicity, religious and political views, personality traits, intelligence, happiness, use of addictive substances, parental separation, age, and gender. The analysis presented is based on a dataset of over 58,000 volunteers who provided their Facebook Likes, detailed demographic profiles, and the results of several psychometric tests. The proposed model uses dimensionality reduction for preprocessing the Likes data, which are then entered into logistic/linear regression to predict individual psychodemographic profiles from Likes. The model correctly discriminates between homosexual and heterosexual men in 88% of cases, African Americans and Caucasian Americans in 95% of cases, and between Democrat and Republican in 85% of cases. For the personality trait “Openness,” prediction accuracy is close to the test–retest accuracy of a standard personality test. We give examples of associations between attributes and Likes and discuss implications for online personalization and privacy.

Changes as an autonomic nervous system ages 11 years - The "Wild Divine" is a bit less wild.

Just after I retired from being a Univ. of Wisconsin department chair in 2001 I bought a set of finger sensors that fit on one's three middle fingers to report skin conductance and heartbeat to a PC or MAC via an A/D converter. These were part of a package with several CDs that installed a new age game on the computer that lead you through a rich environment of classical greek temples and waterfalls, attended by soothing music, that presented tasks in which you dinked with your own heart rate variability and sympathetic (arousing)/parasympathetic (calming) balance, going alternatively through periods of calm and arousal. I thought it was a hoot, and took the time to go through the "Journey to Wild Divine: passage" and "Journey to Wild Divine: Wisdom Quest."

Some of the current incarnations of these programs have moved to web browsers. Over the years a number of heavy weight new age gurus have signed on with their wares - Deepak Chopra, Dean Ornish, and Andrew Weil (Weil was in my Harvard graduating class...I'm tempted, but I won't burden you with my jaded opinion of this class of entrepreneurs, particularly Mr. Chopra.)

The main point of this post is note my experience on pulling out the finger sensors after 11 years trying the same exercises in their new presentation. What's the difference when this 71 year old tries the same manipulations of calm and arousal that the 60 year old played with with 11 years earlier? In a nutshell, I have less command over heart rate variability, which is lower, as the swings between calm and arousal have less amplitude.

And indeed, this fits with the literature on changes in the autonomic nervous system that occur on aging. If you simply do a google search for "autonomic nervous system and aging" numerous references appear that document how healthy aging is associated with lowered heart rate variability, elevated basal sympathetic nervous activity, and reduction of overall autonomic reactivity of sympathetic and parasympathetic nervous systems. Here is a very recent review, from which I pass on one figure:

Schematic of proposed features associated with the imbalance in the autonomic nervous system during aging. During aging there is a shift in the balance of the autonomic nervous system (ANS) towards the sympathetic nervous system (SNS). This may be influenced by circulating or local brain levels of angiotensin (Ang) II and leptin. The lower activity of the parasympathetic nervous system (PSNS) is proposed to result at least in part from an age-related decline in Angiotensin-(1–7). Lower Angiotensin-(1–7) and higher Ang II or leptin in the brain medulla would predispose to a decline in baroreceptor reflex sensitivity (BRS) for control of heart rate and heart rate variability (HRV), both of which are associated with aging. Moreover, impairments in BRS and HRV can contribute to target organ damage, including metabolic dysfunction, with or without an increase in blood pressure. 

If you're inclined, like Mr. Dylan Thomas, to not "go gently into that good night" you can find numerous sources (example here) on slowing these aging changes, usually by some sort of physical movement or stimulation.

Preventing Alzheimer’s associated brain cell atrophy with B vitamin treatment.

I pass this on because it seems like a very striking result. Douaud et al. find that high-dose B-vitamin treatment (folic acid 0.8 mg, vitamin B6 20 mg, vitamin B12 0.5 mg) causes a 7-fold decrease in cerebral atrophy of nerve cell areas most vulnerable to the Alzheimer's process over a 2-year period in a group of elderly subjects with increased dementia risk. (For comparison, Centrum Silver 50+ has Folic Acid 0.4 mg, Vitamin B6 3 mg, and Vitamin B12 0.025 mg.) The supplements decrease plasma levels of one of the bad players in the Alzheimer's story, homocysteine. (Homocysteine is a homologue of the amino acid cysteine,and can be recycled into methionine or converted into cysteine with the aid of B-vitamins.) Here's the abstract:

Is it possible to prevent atrophy of key brain regions related to cognitive decline and Alzheimer’s disease (AD)? One approach is to modify nongenetic risk factors, for instance by lowering elevated plasma homocysteine using B vitamins. In an initial, randomized controlled study on elderly subjects with increased dementia risk (mild cognitive impairment according to 2004 Petersen criteria), we showed that high-dose B-vitamin treatment (folic acid 0.8 mg, vitamin B6 20 mg, vitamin B12 0.5 mg) slowed shrinkage of the whole brain volume over 2 y. Here, we go further by demonstrating that B-vitamin treatment reduces, by as much as seven fold, the cerebral atrophy in those gray matter (GM) regions specifically vulnerable to the AD process, including the medial temporal lobe. In the placebo group, higher homocysteine levels at baseline are associated with faster GM atrophy, but this deleterious effect is largely prevented by B-vitamin treatment. We additionally show that the beneficial effect of B vitamins is confined to participants with high homocysteine (above the median, 11 µmol/L) and that, in these participants, a causal Bayesian network analysis indicates the following chain of events: B vitamins lower homocysteine, which directly leads to a decrease in GM atrophy, thereby slowing cognitive decline. Our results show that B-vitamin supplementation can slow the atrophy of specific brain regions that are a key component of the AD process and that are associated with cognitive decline. Further B-vitamin supplementation trials focusing on elderly subjets with high homocysteine levels are warranted to see if progression to dementia can be prevented.

Here is one figure from the paper:

B-vitamin treatment significantly reduces regional loss of gray matter. (A) Brain regions in blue demonstrate where B-vitamin treatment significantly reduces GM loss over the 2-y period. All blue areas correspond to regions of significant loss in placebo and known to be vulnerable in AD. (B) Percentage of GM loss for the 156 participants over the 2-y period, averaged across those brain regions that showed significant effect of B vitamins: placebo group (red triangles) had an average loss of 3.7% (±3.7), whereas the B-vitamin group (green circles) showed a loss of 0.5% (±2.9).

Visions of our high-tech future: Julian Assange, Jaron Lanier, et al. on Google, Siren servers and the banality of ‘Don’t Be Evil’

The book by Google's Eric Schmidt and Jared Cohen, "The New Digital Age" is a rosy scenario of our high-tech future that many have found a bit creepy and chilling. Since our techie surround will anticipate and take care of our every movement, it seems like we can just sign off and go along for the ride (turning in mental vegetables in the process? …and letting the rule of 'use it or lose it' do it's work on our poor brains?). Also, is it more than a coincidence that at roughly the same time as Schmidt's messianic book is appearing, the movie “The Internship,” a two-hour commercial for GoogleWorld masquerading as an aspirational buddy comedy, also appears in the movie theaters? (You might note this caustic review of the movie.)

Trying to set aside my bias, generated by extensive negative press comments on the behaviors of Wiki-Leaks' Julian Assange, I found his piece in the New York Times on the Schmidt and Cohen book to have some savory and choice screeds. A partial sampling:

“The New Digital Age” is, beyond anything else, an attempt by Google to position itself as America’s geopolitical visionary — the one company that can answer the question “Where should America go?” It is not surprising that a respectable cast of the world’s most famous warmongers has been trotted out to give its stamp of approval to this enticement to Western soft power. The acknowledgments give pride of place to Henry Kissinger, who along with Tony Blair and the former C.I.A. director Michael Hayden provided advance praise for the book.

…“Progress” is driven by the inexorable spread of American consumer technology over the surface of the earth. Already, every day, another million or so Google-run mobile devices are activated. Google will interpose itself, and hence the United States government, between the communications of every human being not in China (naughty China). Commodities just become more marvelous; young, urban professionals sleep, work and shop with greater ease and comfort; democracy is insidiously subverted by technologies of surveillance, and control is enthusiastically rebranded as “participation”; and our present world order of systematized domination, intimidation and oppression continues, unmentioned, unafflicted or only faintly perturbed.

This book is a balefully seminal work in which neither author has the language to see, much less to express, the titanic centralizing evil they are constructing. “What Lockheed Martin was to the 20th century,” they tell us, “technology and cybersecurity companies will be to the 21st.” Without even understanding how, they have updated and seamlessly implemented George Orwell’s prophecy. If you want a vision of the future, imagine Washington-backed Google Glasses strapped onto vacant human faces — forever. Zealots of the cult of consumer technology will find little to inspire them here, not that they ever seem to need it. But this is essential reading for anyone caught up in the struggle for the future, in view of one simple imperative: Know your enemy.

If you want to read what I think is one of the best articles I have seen so far on the unfortunate consequences of our digital universe and possible cures, check out Jaron Lanier's article "Fixing the Digital Economy." It describes the concentration of power and income in the small sliver of the population that designs and runs the massive servers (Siren servers) that analyze different sectors of our lives to minimize their risk and maximize their profits.

Even friendly, consumer-facing Siren Servers ultimately depend on spreading costs to the larger society. Siren Servers can function profitably only if people aren’t paid for the data that is used to calculate their statistical schemes.

Siren Servers drive apart our identities as consumers and workers. In some cases, causality is apparent: free music downloads are great but throw musicians out of work. Free college courses are all the fad, but tenured professorships are disappearing. Free news proliferates, but money for investigative and foreign reporting is drying up. One can easily see this trend extending to the industries of the future, like 3-D printing and renewable energy.

Lanier suggests that we need to nurture a middle class that can thrive even in a highly automated society. One approach:

Institute a universal micropayment system. Keep track of where information came from. Pay people when information that exists because they exist turns out to be valuable, no matter what kind of information is involved or whether a person intended to provide it or not. Let the price be determined by markets.

Person-to-person information markets might lead to a simpler and clearer online world. Because our information systems are designed to initially forget who provided information, services like Google and Bing must constantly scrape the global network to reconstitute the context of data. Siren Servers know who links to your data, but you don’t.

EVEN today’s titanic Siren Servers would benefit from a more monetized information economy, because it would be a healthier-growing economy. The information economy cannot exhibit the long-term growth it ought to if information coming from ordinary people is forever declared to be off the books.

Skeptics sometimes reveal hidden and unfounded wells of elitism. These surface in comments like: “Most people wouldn’t contribute very much.” But there are already empirical hints to counter such pessimism.

In networks with a central point of control, like YouTube or the Apple Store, we do see a Horatio Alger pattern in the distribution of outcomes, where there are very few viable winners and an unbounded number of hopefuls. But in more directly and thickly connected networks like Facebook, we see people typically exposed to a large number of other people, rather than just a few stars. Therefore, if Facebook users paid one another, they would see a less elite distribution of economic benefits.

Another potential benefit of monetized information is to balance the power of government. When information is free, there is no cost to gathering information about citizens. I would like the government, or anyone else, to pay each person each time that person is tracked by a camera. The government should be able to use cameras for security purposes, but in a limited, not unbounded way. Similarly, candidates should not be able to win elections by having the best Siren Servers, but that’s only a problem if the information is free. Citizens should not lose the power of the purse.

As a final note, this Douthat piece regarding the recently revealed NSA snooping on citizens mentions the fact that the problem isn’t that the Internet has been penetrated by the surveillance state; it’s that the Internet, in effect, is a surveillance state.

Penis size and male attractiveness - the most read article in The Proceedings of the National Academy!

I finally had to pass this on.... When I check out the table of contents for new issues of the Proceedings of the National Academy of Science, the right hand column of the page lists most read and most cited articles. For weeks I've been noting that the most read article is "Penis size interacts with body shape and height to influence male attractiveness." I've been trying to avoid it, assuming another evolutionary psychology fairy tale...but, I did have a look. To not deprive MindBlog readers of this gem, I pass on the abstract and one illustration:

Compelling evidence from many animal taxa indicates that male genitalia are often under postcopulatory sexual selection for characteristics that increase a male’s relative fertilization success. There could, however, also be direct precopulatory female mate choice based on male genital traits. Before clothing, the nonretractable human penis would have been conspicuous to potential mates. This observation has generated suggestions that human penis size partly evolved because of female choice. Here we show, based upon female assessment of digitally projected life-size, computer-generated images, that penis size interacts with body shape and height to determine male sexual attractiveness. Positive linear selection was detected for penis size, but the marginal increase in attractiveness eventually declined with greater penis size (i.e., quadratic selection). Penis size had a stronger effect on attractiveness in taller men than in shorter men. There was a similar increase in the positive effect of penis size on attractiveness with a more masculine body shape (i.e., greater shoulder-to-hip ratio). Surprisingly, larger penis size and greater height had almost equivalent positive effects on male attractiveness. Our results support the hypothesis that female mate choice could have driven the evolution of larger penises in humans. More broadly, our results show that precopulatory sexual selection can play a role in the evolution of genital traits.

Figures representing the most extreme height, shoulder-to-hip ratio, and penis size (±2 SD) (Right and Left) in comparison with the average (Center figure) trait values.

We can learn new information during sleep.

Arzi et al. have devised a nice demonstration of how we can learn new information during our sleep. They paired pleasant and unpleasant odors with different tones during sleep, and measured the subjects’ sniffs to tones alone when they were awake. Tones associated with pleasant smells produced stronger sniffs, and tones associated with disgusting smells produced weaker sniffs, despite the subjects’ lack of awareness of the learning process. The abstract:

During sleep, humans can strengthen previously acquired memories, but whether they can acquire entirely new information remains unknown. The nonverbal nature of the olfactory sniff response, in which pleasant odors drive stronger sniffs and unpleasant odors drive weaker sniffs, allowed us to test learning in humans during sleep. Using partial-reinforcement trace conditioning, we paired pleasant and unpleasant odors with different tones during sleep and then measured the sniff response to tones alone during the same nights' sleep and during ensuing wake. We found that sleeping subjects learned novel associations between tones and odors such that they then sniffed in response to tones alone. Moreover, these newly learned tone-induced sniffs differed according to the odor pleasantness that was previously associated with the tone during sleep. This acquired behavior persisted throughout the night and into ensuing wake, without later awareness of the learning process. Thus, humans learned new information during sleep.

Childhood self-control predicts health, wealth, and public safety

An international collaboration between researchers at universities in the US, UK, Canada, and New Zealand has generated this study, which speaks for itself (The participants are members of the Dunedin Multidisciplinary Health and Development Study, which tracks the development of 1,037 individuals born in 1972–1973 in Dunedin, New Zealand.) :

Policy-makers are considering large-scale programs aimed at self-control to improve citizens’ health and wealth and reduce crime. Experimental and economic studies suggest such programs could reap benefits. Yet, is self-control important for the health, wealth, and public safety of the population? Following a cohort of 1,000 children from birth to the age of 32 y, we show that childhood self-control predicts physical health, substance dependence, personal finances, and criminal offending outcomes, following a gradient of self-control. Effects of children's self-control could be disentangled from their intelligence and social class as well as from mistakes they made as adolescents. In another cohort of 500 sibling-pairs, the sibling with lower self-control had poorer outcomes, despite shared family background. Interventions addressing self-control might reduce a panoply of societal costs, save taxpayers money, and promote prosperity.

Self-control gradient. Children with low self-control had poorer health (A), more wealth problems (B), more single-parent child rearing (C), and more criminal convictions (D) than those with high self-control.

MindBlog starts up some summer music - a Poulenc Valse

Calling it summer music is being optimistic... it is still very chilly in Madison. I'm starting to select some pieces for an early fall musical at my Twin Valley home in Middleton, WI. This Poulenc valse is fun and bouncy, and gives me an excuse to relearn the techie side of mixing good quality audio with video.

The chemistry of protecting our brains by fasting.

Actually, I'm making a big assumption in the post title... namely that the results obtained by Gräff et al. in mice would extrapolate to similar finding in the human brain. In several animal models, a reduced consumption of calories seems to protect against cognitive deficits such as memory loss, in addition to acting on many different cell types and tissues to slow down aging. They found that caloric restriction effectively delays the onset of neurodegeneration and preserves structural and functional synaptic plasticity as well as memory capacities. Fasting activates the expression and activity of the nicotinamide adenine dinucleotide (NAD)–dependent protein deacetylase SIRT1, a known promoter of neuronal life span. (A deacetylase is an enzyme that cleaves acetate groups - think acetic acid or vinegar - from their attachment to proteins.) Surprisingly, this effect of reduced consumption of calories is mimicked by a small-molecule SIRT1-activating compound. (Just in case you were curious, the compound is SRT3657 [tertα-butyl 4-((2-(2-(6-(2-(tert-butoxycarbonyl(methyl)amino)ethylamino)-2-butylpyrimidine-4- carboxamido)phenyl)thiazolo[5,4-b]pyridin-6-yl)methoxy)piperidine-1-carboxylate])!! Mice treated with this substance recapitulated the beneficial effects of caloric restriction against neurodegeneration-associated pathologies. If this mechanism also applies to humans, SIRT1 may represent an appealing pharmacological target against neurodegeneration. Here is the abstract:

Caloric restriction (CR) is a dietary regimen known to promote lifespan by slowing down the occurrence of age-dependent diseases. The greatest risk factor for neurodegeneration in the brain is age, from which follows that CR might also attenuate the progressive loss of neurons that is often associated with impaired cognitive capacities. In this study, we used a transgenic mouse model that allows for a temporally and spatially controlled onset of neurodegeneration to test the potentially beneficial effects of CR. We found that in this model, CR significantly delayed the onset of neurodegeneration and synaptic loss and dysfunction, and thereby preserved cognitive capacities. Mechanistically, CR induced the expression of the known lifespan-regulating protein SIRT1, prompting us to test whether a pharmacological activation of SIRT1 might recapitulate CR. We found that oral administration of a SIRT1-activating compound essentially replicated the beneficial effects of CR. Thus, SIRT1-activating compounds might provide a pharmacological alternative to the regimen of CR against neurodegeneration and its associated ailments.

Long-term improvement of brain function and cognition with brain stimulation and cognitive training.

A group of collaborators from the University of Oxford and Innsbruck Medical University have published an observation that simple transcranial random noise stimulation (TRNS) of the bilateral (both sides of the brain) dorsolateral prefrontal cortex (DLPFC) applied during cognitive training over five days causes improvement in learning and performance of complex arithmetic tasks (both calculation and drill leaning) that still persist on testing 6 months later. This correlates with long lasting oxygenated blood flow changes measured by near-infrared spectroscopy that suggests more efficient neurovascular coupling within the left DLPFC. Here is their complete abstract:

Noninvasive brain stimulation has shown considerable promise for enhancing cognitive functions by the long-term manipulation of neuroplasticity. However, the observation of such improvements has been focused at the behavioral level, and enhancements largely restricted to the performance of basic tasks. Here, we investigate whether transcranial random noise stimulation (TRNS) can improve learning and subsequent performance on complex arithmetic tasks. TRNS of the bilateral dorsolateral prefrontal cortex (DLPFC), a key area in arithmetic , was uniquely coupled with near-infrared spectroscopy (NIRS) to measure online hemodynamic responses within the prefrontal cortex. Five consecutive days of TRNS-accompanied cognitive training enhanced the speed of both calculation- and memory-recall-based arithmetic learning. These behavioral improvements were associated with defined hemodynamic responses consistent with more efficient neurovascular coupling within the left DLPFC. Testing 6 months after training revealed long-lasting behavioral and physiological modifications in the stimulated group relative to sham controls for trained and nontrained calculation material. These results demonstrate that, depending on the learning regime, TRNS can induce long-term enhancement of cognitive and brain functions. Such findings have significant implications for basic and translational neuroscience, highlighting TRNS as a viable approach to enhancing learning and high-level cognition by the long-term modulation of neuroplasticity.

For those of you who might well ask "How exactly is TRNS done?" here is a clip from their experimental procedures section. The photograph suggests a rather imposing device!:

Subjects received TRNS while performing the learning task each day. Two electrodes (5 cm × 5 cm) were positioned over areas of scalp corresponding to the DLPFC (F3 and F4, identified in accordance with the international 10-20 EEG procedure; see the figure). Electrodes were encased in saline-soaked synthetic sponges to improve contact with the scalp and avoid skin irritation. Stimulation was delivered by a DC-Stimulator-Plus device (DC-Stimulator-Plus, neuroConn). Noise in the high-frequency band (100–600Hz) was chosen as it elicits greater neural excitation than lower frequency stimulation. For the TRNS group, current was administered for 20 min, with 15 s increasing and decreasing ramps at the beginning and end, respectively, of each session of stimulation. In the sham group current was applied for 30 s after upward ramping and then terminated.

When more support is less....

Finkel and Fitzsimons, whose work I mentioned in a post several years ago, do a review of studies showing that the children of parents who generously finance and regulate in detail their education ("helicopter parenting') make worse grades and feel less satisfied with their lives.

It seems that certain forms of help can dilute recipients’ sense of accountability for their own success. The college student might think: If Mom and Dad are always around to solve my problems, why spend three straight nights in the library during finals rather than hanging out with my friends?

They reference their previous work (see MindBlog link above) showing that this effect generalizes to many 'helping' situations.

Women who thought about how their spouse was helpful with their health and fitness goals became less motivated to work hard to pursue those goals: relative to the control group, these women planned to spend one-third less time in the coming week pursuing their health and fitness goals.

....the problem: how can we help our children (and our spouses, friends and co-workers) achieve their goals without undermining their sense of personal accountability and motivation to achieve them?...The answer, research suggests, is that our help has to be responsive to the recipient’s circumstances: it must balance their need for support with their need for competence. We should restrain our urge to help unless the recipient truly needs it, and even then, we should calibrate it to complement rather than substitute for the recipient’s efforts.

(I like to think that this would be a good description of how I ran my research laboratory, training graduate and post-doctoral students, for 30 years.) A final clip:

...providing help is most effective under a few conditions: when the recipient clearly needs it, when our help complements rather than replaces the recipient’s own efforts, and when it makes recipients feel that we’re comfortable having them depend on us.

So yes, by all means, parents, help your children. But don’t let your action replace their action. Support, don’t substitute. Your children will be more likely to achieve their goals — and, who knows, you might even find some time to get your own social life back on track.

Giant, Glowing Plastic Brain on Wheels

Even though I'm usually a curmudgeon about brain hype,  Obama's Brain initiative, etc., I have to admire the enthusiasm and persistence of CUNY college senior Tyler Alterman, who as his senior thesis project, is trying to get a cognitive science lab on wheels on the road. He hopes that the mobile lab, dubbed The Think Tank, will help close the gender and race gap in STEM skills (science, technology, engineering and math), that are the key to good jobs, through hands-on psych and neuroscience learning at schools and museums.   He has raised $32,000 from crowd funding, and hopes to raise the final $20,000 needed to put the mobile lab on the streets, in part through a public gala on June 18 at the Macaulay Honor College of CUNY.

How we work: 'brain waves' versus modern phrenology

Alexander et al. have analyzed data from magnetoencephalogram (MEG), electroencephalogram (EEG) and electrocorticogram (ECoG), focusing on globally synchronous fields in within-trial evoked brain activity. They quantified several signal components and compared topographies of activation across large-scale cortex. They found the topography of evoked responses was primarily a function of within-trial phase, and within-trial phase topography could be modeled as traveling waves. Traveling waves explained more signal than the trial-averaged phase topography. Here is a edited clip of explanation from Alexander:

The brain can be studied on various scales,..."You have the neurons, the circuits between the neurons, the Brodmann areas – brain areas that correspond to a certain function – and the entire cortex. Traditionally, scientists looked at local activity when studying brain activity, for example, activity in the Brodmann areas. To do this, you take EEG's (electroencephalograms) to measure the brain’s electrical activity while a subject performs a task and then you try to trace that activity back to one or more brain areas."

..."We are examining the activity in the cerebral cortex as a whole. The brain is a non-stop, always-active system. When we perceive something, the information does not end up in a specific part of our brain. Rather, it is added to the brain's existing activity. If we measure the electrochemical activity of the whole cortex, we find wave-like patterns. This shows that brain activity is not local but rather that activity constantly moves from one part of the brain to another. The local activity in the Brodmann areas only appears when you average over many such waves.”

Each activity wave in the cerebral cortex is unique. "When someone repeats the same action, such as drumming their fingers, the motor centre in the brain is stimulated. But with each individual action, you still get a different wave across the cortex as a whole. Perhaps the person was more engaged in the action the first time than he was the second time, or perhaps he had something else on his mind or had a different intention for the action. The direction of the waves is also meaningful. It is already clear, for example, that activity waves related to orienting move differently in children – more prominently from back to front – than in adults. With further research, we hope to unravel what these different wave trajectories mean."

Video: A wave of brain activity measured by the magnetic field it generates externally to the head. The left view of the head is shown on the left side of the image and the right view of the head on the right side of the image. This wave takes about 100 milliseconds to traverse the entire surface of the brain. The travelling wave originates on the lower-left of the head and travels to the lower front-right of the head. Most of the magnetic field shown in this video is generated by brain activity close to the surface of the cortex. The times displayed at the bottom are relative to the subject pressing a button at time zero. The colour scale shows the peak of the wave as hot colours and the trough of the wave as dark colours.

Training our ability to make decisions on uncertain outcomes.

When making decisions, we often retrieve a limited set of items from memory. These retrieved items provide evidence for competing options. For example, a dark cloud may elicit memories of heavy rains, leading one to pack an umbrella instead of sunglasses. Likewise, when viewing an X-ray, a radiologist may retrieve memories of similar X-rays from other patients. Whether or not these other patients have a tumor may provide evidence for or against the presence of a tumor in the current patient. Giguèrea and Love do an interesting study showing how people's ability to make accurate predictions of probabilistic outcomes can be improved if they are trained on an idealized version of a the distribution. They say it in their abstract as clearly as I can:

Some decisions, such as predicting the winner of a baseball game, are challenging in part because outcomes are probabilistic. When making such decisions, one view is that humans stochastically and selectively retrieve a small set of relevant memories that provides evidence for competing options. We show that optimal performance at test is impossible when retrieving information in this fashion, no matter how extensive training is, because limited retrieval introduces noise into the decision process that cannot be overcome. One implication is that people should be more accurate in predicting future events when trained on idealized rather than on the actual distributions of items. In other words, we predict the best way to convey information to people is to present it in a distorted, idealized form. Idealization of training distributions is predicted to reduce the harmful noise induced by immutable bottlenecks in people’s memory retrieval processes. In contrast, machine learning systems that selectively weight (i.e., retrieve) all training examples at test should not benefit from idealization. These conjectures are strongly supported by several studies and supporting analyses. Unlike machine systems, people’s test performance on a target distribution is higher when they are trained on an idealized version of the distribution rather than on the actual target distribution. Optimal machine classifiers modified to selectively and stochastically sample from memory match the pattern of human performance. These results suggest firm limits on human rationality and have broad implications for how to train humans tasked with important classification decisions, such as radiologists, baggage screeners, intelligence analysts, and gamblers.

Here are some clips from their text:

For probabilistic problems, such as determining whether a tumor is cancerous, whether it will rain, or whether a passenger is a security threat, selectively sampling memory at the time of decision makes it impossible for the learner to overcome uncertainty in the training domain. From a signal-detection perspective, selective sampling from memory results in noisy and inconsistent placement of the criterion across decision trials. Even with a perfect memory for all past experiences, a learner who selectively samples from memory will perform suboptimally on ambiguous category structures

Figure (A) Categories A (red curve) and B (green curve) are probabilistic, overlapping distributions. After experiencing many training items (denoted by the red A and green B letters), an optimal classifier places the decision criterion (dotted line) to maximize accuracy, and will classify all new test items to left of the criterion as A and all items to the right of the criterion as B. (B) Thus, the optimal classifier will always judge item S8 to be an A. In contrast, a model that stochastically and nonexhaustively samples similar items from memory may retrieve the three circled items and classify S8 as a B, which is not the most likely category. This sampling model will never achieve optimal performance when trained on ambiguous category structures. (C) Idealizing the category structures during training such that all items to the left of the criterion are labeled as A and to the right as B (underlined items are idealized) leads to optimal performance for both the optimal classifier and the selective sampling model.

Renewing our brain's ability to make decisions.

Our dopamine neurons, which enable enable our brains to make better choices, based on outcomes, gradually die off as part of the normal aging process.  Chowdhury and colleagues have now found that increasing dopamine levels in the brain of healthy older participants increased the rate with which they learned from rewarding outcomes and changed activity in the striatum, a brain region that supports learning from rewards. To relate brain activity and behavior, they utilized fMRI, diffusion tensor imaging, reinforcement learning tasks, and computational models of behavior. Their data might suggest that some variant of the dopamine therapy used for Parkinson's disease patient, might help older people make decisions. Here is their more technical abstract:

Senescence affects the ability to utilize information about the likelihood of rewards for optimal decision-making. Using functional magnetic resonance imaging in humans, we found that healthy older adults had an abnormal signature of expected value, resulting in an incomplete reward prediction error (RPE) signal in the nucleus accumbens, a brain region that receives rich input projections from substantia nigra/ventral tegmental area (SN/VTA) dopaminergic neurons. Structural connectivity between SN/VTA and striatum, measured by diffusion tensor imaging, was tightly coupled to inter-individual differences in the expression of this expected reward value signal. The dopamine precursor levodopa (L-DOPA) increased the task-based learning rate and task performance in some older adults to the level of young adults. This drug effect was linked to restoration of a canonical neural RPE. Our results identify a neurochemical signature underlying abnormal reward processing in older adults and indicate that this can be modulated by L-DOPA.

The limits of empathy

I thought I would follow up the Monday's post on well being, kindness, happiness and all that good stuff by noting a piece on how feel-good energy can lead us astray. Yale psychologist Paul Bloom has done an excellent article in the May 20 issue of the The New Yorker titled “The baby in the well - the limits of empathy.” Well meant feelings and actions of empathy can in some cases be counterproductive and blind us to more remote but statistically much more important hardships. Our evolved ability to feel what others are feeling (see numerous mindblog posts on mirror neurons, etc. ) is applied to very explicit and limited human situations, usually a specific individual (6 year old girl falls in well and nation focuses on watching the rescue) or defined and limited groups (mass shootings at Sandy Hook or Boston Marathon bombing). From Bloom:

In the past three decades, there were some sixty mass shootings, causing about five hundred deaths; that is, about one-tenth of one per cent of the homicides in America. But mass murders get splashed onto television screens, newspaper headlines, and the Web; the biggest ones settle into our collective memory —Columbine, Virginia Tech, Aurora, Sandy Hook. The 99.9 per cent of other homicides are, unless the victim is someone you’ve heard of, mere background noise.

After noting how empathy research is thriving, and several books arguing that more empathy has to be a good thing (with Rifkin, in “The Empathic Civilization” (Penguin), wanting us to make the leap to “global empathic consciousness”), Bloom notes:

This enthusiasm may be misplaced, however. Empathy has some unfortunate features—it is parochial, narrow-minded, and innumerate. We’re often at our best when we’re smart enough not to rely on it......the key to engaging empathy is what has been called “the identifiable victim effect.” As the economist Thomas Schelling, writing forty-five years ago, mordantly observed, “Let a six-year-old girl with brown hair need thousands of dollars for an operation that will prolong her life until Christmas, and the post office will be swamped with nickels and dimes to save her. But let it be reported that without a sales tax the hospital facilities of Massachusetts will deteriorate and cause a barely perceptible increase in preventable deaths—not many will drop a tear or reach for their checkbooks.”

You can see the effect in the lab. The psychologists Tehila Kogut and Ilana Ritov asked some subjects how much money they would give to help develop a drug that would save the life of one child, and asked others how much they would give to save eight children. The answers were about the same. But when Kogut and Ritov told a third group a child’s name and age, and showed her picture, the donations shot up—now there were far more to the one than to the eight.

In the broader context of humanitarianism, as critics like Linda Polman have pointed out, the empathetic reflex can lead us astray. When the perpetrators of violence profit from aid—as in the “taxes” that warlords often demand from international relief agencies—they are actually given an incentive to commit further atrocities.

A “politics of empathy” doesn’t provide much clarity in the public sphere, either. Typically, political disputes involve a disagreement over whom we should empathize with. Liberals argue for gun control, for example, by focussing on the victims of gun violence; conservatives point to the unarmed victims of crime, defenseless against the savagery of others.

On many issues, empathy can pull us in the wrong direction. The outrage that comes from adopting the perspective of a victim can drive an appetite for retribution....In one study, conducted by Jonathan Baron and Ilana Ritov, people were asked how best to punish a company for producing a vaccine that caused the death of a child. Some were told that a higher fine would make the company work harder to manufacture a safer product; others were told that a higher fine would discourage the company from making the vaccine, and since there were no acceptable alternatives on the market the punishment would lead to more deaths. Most people didn’t care; they wanted the company fined heavily, whatever the consequence.

There’s a larger pattern here. Sensible policies often have benefits that are merely statistical but victims who have names and stories. Consider global warming—what Rifkin calls the “escalating entropy bill that now threatens catastrophic climate change and our very existence.” As it happens, the limits of empathy are especially stark here. Opponents of restrictions on CO2 emissions are flush with identifiable victims—all those who will be harmed by increased costs, by business closures. The millions of people who at some unspecified future date will suffer the consequences of our current inaction are, by contrast, pale statistical abstractions.

Moral judgment entails more than putting oneself in another’s shoes. “The decline of violence may owe something to an expansion of empathy,” the psychologist Steven Pinker has written, “but it also owes much to harder-boiled faculties like prudence, reason, fairness, self-control, norms and taboos, and conceptions of human rights.” A reasoned, even counter-empathetic analysis of moral obligation and likely consequences is a better guide to planning for the future than the gut wrench of empathy.

Newtown, in the wake of the Sandy Hook massacre, was inundated with so much charity that it became a burden. More than eight hundred volunteers were recruited to deal with the gifts that were sent to the city—all of which kept arriving despite earnest pleas from Newtown officials that charity be directed elsewhere....Meanwhile—just to begin a very long list—almost twenty million American children go to bed hungry each night, and the federal food-stamp program is facing budget cuts of almost twenty per cent.

Such are the paradoxes of empathy. The power of this faculty has something to do with its ability to bring our moral concern into a laser pointer of focussed attention. If a planet of billions is to survive, however, we’ll need to take into consideration the welfare of people not yet harmed—and, even more, of people not yet born. They have no names, faces, or stories to grip our conscience or stir our fellow-feeling. Their prospects call, rather, for deliberation and calculation. Our hearts will always go out to the baby in the well; it’s a measure of our humanity. But empathy will have to yield to reason if humanity is to have a future.

Transferring from Google Reader to Feedly

I've just finished editing and culling the "Other Mind Blogs" list in the right column of this blog.  If you are now getting the feeds of any of these or Deric's MindBlog from Google Reader, which shuts down on July 1,  they can all be automatically transferred to the Feedly reader at Feedly.com.   The search box at the upper right corner of the Feedly page lets you enter URLS of further blogs or news sources you wish to follow. (For a more thorough listing of options, see my March 26 post.)

On well-being - An orgy of good energy last week in Madison, Wisconsin.

In spite of slightly flippant title for this post, I really do believe this is good stuff. The Dali Lama paid a two day visit to Madison Wisconsin last week, as part of his current world tour “Change Your Mind, Change The World,” speaking at a number of different venues (all under high security screening) under the sponsorship of the Center for Investigating Healthy Minds and the Global Health Institute, both at the University of Wisconsin-Madison. My colleague Richard Davidson, who was central in arranging his visit, is doing an amazing job of bringing to the general public neuroscientific and psychological insight into well-being and happiness. (side note: Davidson contributed to a brain imaging seminar I organized for the graduate Neuroscience program in the 1980’s.) An example his public outreach is this recent piece in The Huffington Post.

The point that I find most compelling, and it certainly resonates with my own experience, is the hard evidence that kindness and generosity are innate human predispositions whose exercise is more effective in promoting a sense of well being than explicitly self-serving behaviors. (Of course, this message has been a component of the major religious traditions for thousands of years.) There is accumulating evidence that kind and generous behavior reduces inflammatory chemistry in our bodies.

I have used the tag ‘happiness’ and 'mindfulness' (in the left column) to mark numerous posts on well-being over the past seven years. Right now my queue of potential posts in this area has more items that I will ever get to individually. So...I thought I would just list a few of them for MindBlog readers who might wish to check some of them out:

On happiness, from the New York Times Opinionator column.

A 75-year Harvard Study's finding on what it takes to live a happy life. 

A brief New York Times piece on mindfulness.

How your mind wandering robs you of happiness. (also, enter ‘mind wandering’ in the blog’s search box)

Is giving the secret to getting ahead.

On money and well being.