During learning - competition between two memory systems.

An interesting bit of work from Lee et al.:

The multiple memory systems framework proposes that distinct circuits process and store different sorts of information; for example, spatial information is processed by a circuit that includes the hippocampus, whereas certain forms of instrumental conditioning depend on the striatum. Disruption of hippocampal function can enhance striatum-dependent learning in some paradigms, which has been interpreted as evidence that these systems can compete with one another in an intact animal. However, it remains unclear whether such competition can occur in the opposite direction, as suggested by the multiple memory systems framework, or is unidirectional. We addressed this question using lesions and genetic manipulations in mice. Impairment of dorsal striatal function with either excitotoxic lesions or transgenic inhibition of the transcription factor cAMP response element-binding protein, which disrupts striatal synaptic plasticity, impaired striatum-dependent cued learning but enhanced hippocampus-dependent spatial learning. Conversely, excitotoxic lesions of the dorsal hippocampus disrupted spatial learning and enhanced cued learning. This double dissociation demonstrates bidirectional competition that constitutes strong evidence for the parallel operation of distinct memory systems.

Enhanced logical consistency in autism.

Dolan's group has an interesting open access article in J. Neuroscience showing:

behavioral evidence that autism spectrum disorder (ASD) subjects show a reduced susceptibility to the framing effect and psycho-physiological evidence that they fail to incorporate emotional context into the decision-making process.

From their introduction:

Logical consistency across decisions, regardless of how choices are presented, is a central tenet of rational choice theory and the cornerstone of modern economic and political science. Empirical data challenge this perspective by showing that humans are highly susceptible to the manner or context in which options are cast, resulting in a decision bias termed the "framing effect". We have previously shown that the amygdala mediates this framing bias, a finding that highlights the importance of incorporating emotional processes within models of human decision making. An ability to integrate emotional contextual information into the decision process provides a useful heuristic in decision making under uncertainty. This is a factor that is likely to assume considerable importance during social interactions in which information about others is often incomplete, ambiguous, and not easily amenable to standard inferential reasoning processes.

In this study, we investigated the effect of contextual frame on choice behavior of individuals with autistic spectrum disorder (ASD). Autism is a neurodevelopmental disorder characterized by deficits in social interaction, qualitative impairments in communication, and repetitive and stereotyped patterns of behavior, interests, and activities. From Kanner's earliest description, it has been recognized that individuals with ASD have a strong tendency to focus on parts rather than global aspects of objects of interest and are unable to integrate disparate information into a meaningful whole (weak central coherence theory).

We previously proposed that susceptibility to a framing bias reflects the operation of an affect heuristic. Here, we show that individuals with ASD, a condition characterized by marked behavioral inflexibility, demonstrate a decreased susceptibility to framing resulting in an unusual enhancement in logical consistency that is paradoxically more in line with the normative prescriptions of rationality at the core of the current economics theory. Furthermore, insensitivity in these subjects to a contextual framing bias was associated with a failure to express a differential autonomic response to contextual cues as indexed in skin conductance responses (SCRs), a standard measure of emotional processing. Our findings suggest that a more consistent pattern of choice in the ASD group reflects a failure to incorporate emotional cues into the decision process, an enhanced economic "rationality" that may come at a cost of reduced behavioral flexibility.

Using both sides of your brain.

Schmidt writes a review article on specializations of the two hemispheres, which are seen in all vertebrates. He gives several examples of interhemispheric switching, and then focuses on the example of song production in passerine birds.

Chill-out...

From the "Random Samples" section of the Oct. 31 Science Magazine:

Psychologists at the University of Hertfordshire, U.K., last week unveiled what they are billing as "the world's most relaxing room." The 160-square-meter space, bathed in green lights with an artificially lit blue sky, is furnished with soft mats and lavender-scented pillows "to create a relaxing environment with no sense of threat," explains the project's mastermind Richard Wiseman.

The design is based on research on the effects of light, scent, and music in relaxation. "Cold colors such as blue and green tend to be perceived as calming, whereas warm colors can be perceived as arousing," explains Birgitta Gatersleben, an environmental psychologist from the University of Surrey in Guildford, U.K. Lavender is said to reduce anxiety and induce sleep by lowering the levels of the stress hormone cortisol. The room also features specially composed music with a slow, steady beat and low-frequency tones.

So far, the room's 200 visitors have given it mixed reviews. "Some people absolutely love it and can't have enough of it," Wiseman says. "But people who thrive on and need stress to work absolutely hate it."

The project was designed to be easy to replicate in offices and other real-life environments. "I would like to see relaxation rooms in public spaces," Wiseman adds. "If we pay 20p to use a toilet in King's Cross train station, why not pay for 20 minutes of peace?"

Symbolic markers, cultural groups, and ingroup favoritism

A 'This week in Science' section of Science Magazine points to the work of Efferson et al. :

In human social interactions, it is not uncommon to draw inferences about hidden characteristics (attitudes, beliefs, or behavioral norms) on the basis of observable markers that may bear no fundamental connection to the underlying quantity but have become associated with specific groups over time. For instance, individuals sporting insignia of the Boston Red Sox or Manchester United may be classified as friends (or foes, if one should happen to be a New York Yankees or Chelsea fan). Although much research has been devoted to how a member of one cultural or ethnic group views other in-group and out-group members, less is known about the process by which symbolic markers come to be used as signals to define group membership. Efferson et al. have designed a laboratory-based economic game in which subjects were free to associate arbitrary markers with varying payoffs. Cultural groups (those in which members had adopted the same marker) and consequent ingroup favoritism developed only when the marker was both predictive of behavior in the game as well as changeable over time.

The abstract from Efferson et al.:

Cultural boundaries have often been the basis for discrimination, nationalism, religious wars, and genocide. Little is known, however, about how cultural groups form or the evolutionary forces behind group affiliation and ingroup favoritism. Hence, we examine these forces experimentally and show that arbitrary symbolic markers, though initially meaningless, evolve to play a key role in cultural group formation and ingroup favoritism because they enable a population of heterogeneous individuals to solve important coordination problems. This process requires that individuals differ in some critical but unobservable way and that their markers be freely and flexibly chosen. If these conditions are met, markers become accurate predictors of behavior. The resulting social environment includes strong incentives to bias interactions toward others with the same marker, and subjects accordingly show strong ingroup favoritism. When markers do not acquire meaning as accurate predictors of behavior, players show a markedly reduced taste for ingroup favoritism. Our results support the prominent evolutionary hypothesis that cultural processes can reshape the selective pressures facing individuals and so favor the evolution of behavioral traits not previously advantaged.

Values of early music training.

Forgeard et al. show that children who receive at least three years of instrumental music training outperform their control counterparts on auditory discrimination abilities and fine motor skills, as well as vocabulary and nonverbal reasoning skills. They did not confirm a suggestion from previous research that music training enhances heightened spatial skills, phonemic awareness, or mathematical abilities.

The creationists go to war over the brain.

A Zoology colleague of mine pointed out an article by Amander Gefter (PDF here) in The New Scientist on a group of "non-materialist neuroscientists" that is trying to resurrect Cartesian Dualism. It is particularly sad that one of these is Jeffrey Schwartz, who has done classic work showing how cognitive therapy can amelioate obsessive compulsive disorder.

Schwartz used scanning technology to look at the neural patterns thought to be responsible for OCD. Then he had patients use "mindful attention" to actively change their thought processes, and this showed up in the brain scans: patients could alter their patterns of neural firing at will. From such experiments, Schwartz and others argue that since the mind can change the brain, the mind must be something other than the brain, something non-material. In fact, these experiments are entirely consistent with mainstream neurology - the material brain is changing the material brain.

Clearly, while there is a genuine attempt to appropriate neuroscience, it will not influence US laws or education in the way that anti-evolution campaigns can because neuroscience is not taught as part of the core curriculum in state-funded schools. But as Andy Clark, professor of logic and metaphysics at the University of Edinburgh, UK, emphasises: "This is real and dangerous and coming our way." He and others worry because scientists have yet to crack the great mystery of how consciousness could emerge from firing neurons. "Progress in science is slow on many fronts," says John Searle, a philosopher at the University of California, Berkeley. "We don't yet have a cure for cancer, but that doesn't mean cancer has spiritual causes." And for Patricia Churchland, a philosopher of neuroscience at the University of California, San Diego, "it is an argument from ignorance. The fact something isn't currently explained doesn't mean it will never be explained or that we need to completely change not only our neuroscience but our physics." The attack on materialism proposes to do just that, but it all turns on definitions. "At one time it looked like all physical causation was push/pull Newtonianism," says Owen Flanagan, professor of philosophy and neurobiology at Duke University, North Carolina. "Now we have a new understanding of physics. What counts as material has changed. Some respectable philosophers think that we might have to posit sentience as a fundamental force of nature or use quantum gravity to understand consciousness. These stretch beyond the bounds of what we today call 'material', and we haven't discovered everything about nature yet. But what we do discover will be natural, not supernatural."

And as Clark observes: "This is an especially nasty mind-virus because it piggybacks on some otherwise reasonable thoughts and worries. Proponents make such potentially reasonable points as 'Oh look, we can change our brains just by changing our minds,' but then leap to the claim that mind must be distinct and not materially based. That doesn't follow at all. There's nothing odd about minds changing brains if mental states are brain states: that's just brains changing brains."

A conference on "Happiness and its Causes."

There is a "Happiness and its Causes" conference in San Francisco Nov. 24-25, with very flashy marketing and quite a cast of stars: Paul Ekman, Robert Sapolsky, Anne Harrington and others.

Our brain's large scale functional architecture.

He et al. have published an important study that shows correlations between spontaneous fluctuations in slow cortical potentials recorded by electrocorticography and fMRI BOLD signals are maintained across wakefulness, slow-wave sleep, and rapid-eye-movement sleep. Balduzzi et al. note in their review of the work that the study

... makes it clear that both BOLD and ECoG fluctuations display a pattern of regional correlations, or functional connectivity, which closely reflects those regions' anatomical connectivity. Inverting a well known adagio, what wires together, fires together. Indeed, it seems that it could not be otherwise. If neurons are connected in a certain way, and if they are spontaneously active, functional connectivity is bound to reflect anatomical connectivity, just like traffic patterns must reflect the underlying roadmap.

The reviewers also give a nice description of alternative ideas about what the brain's spontaneous or background activity might be for:

The steady depolarization and firing of neurons, even when the brain is supposedly “at rest,” also called the “default mode” of activity, consumes approximately two-thirds of the brain's already disproportionate energy budget, so it better do something useful. For instance, spontaneous activity may be important for the brain's trillions of synapses, perhaps by keeping them exercised or consolidating and renormalizing their strength. Another notion is that spontaneous activity may be necessary to maintain a fluid state of readiness that allows the cortex to rapidly enter any of a number of available states or firing patterns—a kind of metastability. Theoretical work suggests that the repertoire of available states is maximal under moderate spontaneous activity, and shrinks dramatically with either complete inactivity or hyperactivity. But what kind of neural states? One possibility is that the cortex is like a sea undulating gently, and that evoked or task-related responses would be like small ripples on its surface. This possibility is consistent with fMRI studies, because spontaneous slow fluctuations in BOLD are as large or larger than those evoked by stimuli. Also, it would fit nicely with the trial-to-trial variability of behavioral responses. Another possibility is that there are distinct modes of neuronal activity, such as a READY mode and a GO mode (and possibly an inhibited, STOP mode). Spontaneous activity would then be the READY mode of neuronal firing signaling the absence of preferred stimuli (an ongoing, low-level buzz). By contrast, in the GO mode, neurons, or local populations of neurons, would signal the presence of a preferred stimulus by firing at much higher rates for short periods of time (a brief and loud shout). Unit recording studies have provided plenty of evidence that neurons respond strongly and distinctly to specific stimuli. In this view, the cortex would be more like a sea pierced by sharp islands. On the other hand, the slow hemodynamic response function underlying the BOLD signal may make fMRI partly blind to the distinction between slow, low-amplitude fluctuations in firing and fast, high-amplitude bursts of activity. If there are two modes of neural activity, it bears keeping in mind that neurons in the READY mode would be as necessary as neurons in the GO mode in specifying different cognitive states, just as the background is as necessary as the foreground.

The belt of enlightenment...

A map, via Andrew Sullivan's blog, of the counties, mainly in Arkansas through Appalachia, in which more people voted republican in 2008 than in 2004. Overlaps with maps of ignorance, racism and poverty. Not many MindBlog readers in this region!

Could you figure this out?

Get the peanut out of the tube:

Language conflict in the bilingual brain

An open access article by Van Heuven et al. in Cerebral Cortex:

The large majority of humankind is more or less fluent in 2 or even more languages. This raises the fundamental question how the language network in the brain is organized such that the correct target language is selected at a particular occasion. Here we present behavioral and functional magnetic resonance imaging data showing that bilingual processing leads to language conflict in the bilingual brain even when the bilinguals’ task only required target language knowledge. This finding demonstrates that the bilingual brain cannot avoid language conflict, because words from the target and nontarget languages become automatically activated during reading. Importantly, stimulus-based language conflict was found in brain regions in the LIPC associated with phonological and semantic processing, whereas response-based language conflict was only found in the pre-supplementary motor area/anterior cingulate cortex when language conflict leads to response conflicts.

Disputed definitions: paradigm shift

NatureNews has an interesting article on words whose definitions get scientists most worked up. Take 'paradigm shift,' for example:

Paradigm shift has a definite origin and originator: Thomas Kuhn, writing in his 1962 book The Structure of Scientific Revolutions, argued against the then prevalent view of science as an incremental endeavour marching ever truthwards. Instead, said Kuhn, most science is "normal science", which fills in the details of a generally accepted, shared conceptual framework. Troublesome anomalies build up, however, and eventually some new science comes along and overturns the previous consensus. Voilà, a paradigm shift. The classic example, Kuhn said, is the Copernican revolution, in which Ptolemaic theory was swept away by putting the Sun at the centre of the Solar System. Post-shift, all previous observations had to be reinterpreted.

Kuhn's theory about how science works was arguably a paradigm shift of its own, by changing the way that academics think about science. And scientists have been using the phrase ever since.

In a postscript to the second edition of his book, Kuhn explained that he used the word 'paradigm' in at least two ways (noting that one "sympathetic reader" had found 22 uses of the term). In its broad form, it encompasses the "entire constellation of beliefs, values, techniques and so on shared by the members of a given community". More specifically it refers to "the concrete puzzle-solutions" that are used as models for normal science post-shift.

Scientists who use the term today don't usually mean that their field has undergone a Copernican-scale revolution, to the undying annoyance of many who hew to Kuhn's narrower definition. But their usage might qualify under his broader one. And so usage becomes a matter of opinion and, perhaps, vanity.

The use of the term in titles and abstracts of leading journals jumped from 30 papers in 1991 to 124 in 1998, yet very few of these papers garnered more than 10 citations apiece1. Several scientists contacted for this article who had used paradigm shift said that, in retrospect, they were having second thoughts. In 2002, Stuart Calderwood, an oncologist at Harvard Medical School in Boston, Massachusetts, used it to describe the discovery that 'heat shock proteins', crucial to cell survival, could work outside the cell as well as in2. "If you work in a field for a long time and everything changes, it does seem like a revolution," he says. But now he says he may have misused the phrase because the discovery was adding to, rather than overturning, previous knowledge in the field.

Arvid Carlsson, of the University of Gothenburg in Sweden stands by his use of the phrase. "Until a certain time, the paradigm was that cells communicate almost entirely by electrical signals," says Carlsson. "In the 1960s and '70s, this changed. They do so predominantly by chemical signals. In my opinion, this is dramatic enough to deserve the term paradigm shift." Few would disagree: base assumptions were overturned in this case, and Carlsson's own work on the chemical neurotransmitter dopamine (which was instrumental in this particular shift) earned him the 2000 Nobel Prize in Physiology or Medicine

Unless a Nobel prize is in the offing, it might be wise for scientists to adopt the caution of contemporary historians of science and think twice before using a phrase with a complex meaning and a whiff of self promotion. "Scientists all want to be the scientists that generate a new revolution," says Kuhn's biographer, Alexander Bird, a philosopher at the University of Bristol, UK. "But if Kuhn is right, most science is normal science and most people can't perform that role."

A break from watching the election returns....

The psychology of voting - US readers: VOTE TODAY!

An interesting article in today's New York Times Science section by Benedict Carey, on the value of voting beyond politics.

Neuroeconomics - the neural circuitry of overbidding

Delgado et al. offer an interesting article in Science Magazine suggesting that fear of loss may mediate overbidding in auctions. Here is their abstract, followed by comments in a review by Maskin.

We take advantage of our knowledge of the neural circuitry of reward to investigate a puzzling economic phenomenon: Why do people overbid in auctions? Using functional magnetic resonance imaging (fMRI), we observed that the social competition inherent in an auction results in a more pronounced blood oxygen level–dependent (BOLD) response to loss in the striatum, with greater overbidding correlated with the magnitude of this response. Leveraging these neuroimaging results, we design a behavioral experiment that demonstrates that framing an experimental auction to emphasize loss increases overbidding. These results highlight a role for the contemplation of loss in understanding the tendency to bid "too high." Current economic theories suggest overbidding may result from either "joy of winning" or risk aversion. By combining neuroeconomic and behavioral economic techniques, we find that another factor, namely loss contemplation in a social context, may mediate overbidding in auctions.

Maskin's comments are based on followup experiments not mentioned in the abstract:

The fMRI data show that subjects experience a lower blood oxygen level in the striatum in response to losing an auction, but no significant change in reaction to winning one. The authors interpret this result as suggesting that subjects experience "fear of losing" and that this fear accounts for their overbidding. But actually modeling fear explicitly--making it precise--does not seem straightforward.

A natural modeling device would be simply to subtract something from the subject's payoff when she loses. However, such a modification would not accord with the authors' findings in their subsequent experiment. In the follow-up, there were two treatments: one in which a subject is initially given a bonus sum of money S but told that she has to return it if she loses the auction; the other in which the subject is promised that if she wins she will get S. The two treatments are, ex post, identical: In both cases, the subject ends up with the bonus if and only if she wins. However, in practice, subjects bid more in the former treatment than the latter. Such behavior sharply contradicts the "payment subtraction" hypothesis, under which behavior in the two treatments would be the same. Moreover, it seems difficult to find a natural alternative formulation of the "fear of losing" idea that explains the results simultaneously from both Delgado et al. experiments. Even so, there is a well-known principle that could account for the behavioral discrepancy between the two treatments in the follow-up experiment: the "endowment" effect. When a subject is given a bonus S at the outset, she may become possessive and so move more aggressively to retain it than she would act to obtain a contingent bonus at the end of the experiment.

As for why subjects overbid, perhaps the answer is that high-bid auctions are just too complex for a typical buyer to analyze completely systematically. The buyer will easily see that she has to shade her bid (bid strictly below v) to get a positive payoff. Still, she won't want to shade too much because shading reduces her probability of winning. A simple rule of thumb would be to shade just a little. But this leads immediately to overbidding, because risk-neutral equilibrium bidding entails a great deal of shading: A buyer will bid only one-half her valuation.

The behavioral revolution in economics

In light of the work by Delgado et al. mentioned in today's other posting, I thought it appropriate to pass on this NY Times Op-Ed piece by David Brooks, on the decline of economic models that presume that people are mostly engaged in rationally calculating and maximizing their self-interest. Rather, people put great energy in perceiving things that aren't true. Brooks emphasizes the work of Taleb:

Taleb believes that our brains evolved to suit a world much simpler than the one we now face. His writing is idiosyncratic, but he does touch on many of the perceptual biases that distort our thinking: our tendency to see data that confirm our prejudices more vividly than data that contradict them; our tendency to overvalue recent events when anticipating future possibilities; our tendency to spin concurring facts into a single causal narrative; our tendency to applaud our own supposed skill in circumstances when we’ve actually benefited from dumb luck.

And looking at the financial crisis, it is easy to see dozens of errors of perception. Traders misperceived the possibility of rare events. They got caught in social contagions and reinforced each other’s risk assessments. They failed to perceive how tightly linked global networks can transform small events into big disasters.

Explanatory Neurophilia - seduction without cause

Trout discusses the work of Weinberg (mentioned in a previous post) who has shown in a series of experiment how non-expert consumers of behavioral explanations assign greater standing to explanations that contain neuroscientific details, even if these details provide no additional explanatory value. He discusses the part that this ‘placebic’ information might play in producing a potentially misleading sense of intellectual fluency and, consequently, an unreliable sense of understanding. I'm passing the article on to you here.

Happiness, Eudaimonia, etc.

As I was doing some homework in preparation for a gig as a talking heading ‘expert’ on a web radio show called “Make Me Happy” I ran across this 2002 article, “Pleasure, Meaning & Eudaimonia” by Martin Seligman.

So the core thesis in Authentic Happiness is that there are three very different routes to happiness. First the Pleasant Life, consisting in having as many pleasures as possible and having the skills to amplify the pleasures. This is, of course, the only true kind of happiness on the Hollywood view. Second, the Good Life, which consists in knowing what your signature strengths are, and then recrafting your work, love, friendship, leisure and parenting to use those strengths to have more flow in life. Third, the Meaningful Life, which consists of using your signature strengths in the service of something that you believe is larger than you are.

MindBlog as election worker...

I got a call from the Obama campaign asking if I would work as a poll watcher at an election polling site on Tuesday. I said yes, went to the training session yesterday (shown at left), and came away in awe of the micro-analytical detail and power of the Obama ground effort. Our main job is to be sure people make it through the long waiting lines, give out registration information and assistance, be alert for any signs of voter intimidation. Another class of poll worker, designated a "Houdini", records the identity of every voter, and at 30 min- 1hr intervals calls in the information to command central, which takes those names off the canvass and phone lists to reallocate resources in real time towards getting out the people who haven't voted.