Thursday, June 30, 2011

Consciousness - correlation is not a cause

Here are excerpts from Susan Blackmore's contribution to the Edge.org question "What scientific concept would improve everybody's cognitive toolkit?"

The phrase "correlation is not a cause" (CINAC) may be familiar to every scientist but has not found its way into everyday language, even though critical thinking and scientific understanding would improve if more people had this simple reminder in their mental toolkit.

One reason for this lack is that CINAC can be surprisingly difficult to grasp. I learned just how difficult when teaching experimental design to nurses, physiotherapists and other assorted groups. They usually understood my favourite example: imagine you are watching at a railway station. More and more people arrive until the platform is crowded, and then — hey presto — along comes a train. Did the people cause the train to arrive (A causes B)? Did the train cause the people to arrive (B causes A)? No, they both depended on a railway timetable (C caused both A and B).

Stories of health scares and psychic claims may get people's attention but understanding that a correlation is not a cause could raise levels of debate over some of today's most pressing scientific issues. For example, we know that global temperature rise correlates with increasing levels of atmospheric carbon dioxide but why? Thinking Cinacally means asking which variable causes which or whether something else causes both, with important consequences for social action and the future of life on earth.

Some say that the greatest mystery facing science is the nature of consciousness. We seem to be independent selves having consciousness and free will, and yet the more we understand how the brain works, the less room there seems to be for consciousness to do anything. A popular way of trying to solve the mystery is the hunt for the "neural correlates of consciousness". For example, we know that brain activity in parts of the motor cortex and frontal lobes correlates with conscious decisions to act. But do our conscious decisions cause the brain activity, does the brain activity cause our decisions, or are both caused by something else?

The fourth possibility is that brain activity and conscious experiences are really the same thing, just as light turned out not to be caused by electromagnetic radiation but to be electromagnetic radiation, or heat turned out to be the movement of molecules in a fluid. At the moment we have no inkling of how consciousness could be brain activity but my guess is that it will turn out that way. Once we clear away some of our delusions about the nature of our own minds, we may finally see why there is no deep mystery and our conscious experiences simply are what is going on inside our brains. If this is right then there are no neural correlates of consciousness. But whether it is or not, remembering CINAC and working slowly from correlations to causes is likely to be how this mystery is finally solved.

Wednesday, June 29, 2011

Internet use restructures the brain

An interesting study out of China by Yuan et al. does fMRI studies of the brains of Chinese college-age students self-diagnosed with "internet addiction disorder" (i.e. obsessive online game players) and finds decreased gray matter volume in the bilateral dorsolateral prefrontal cortex (DLPFC), the supplementary motor area (SMA), the orbitofrontal cortex (OFC), the cerebellum and the left rostral ACC (rACC), along with changes in deeper brain structures. It doesn't seem all that surprising that playing online games 10-12 hours a day might cause brain changes. Intensive sports or musical instrument practice also cause changes in the relevant brain areas.

Note, from Mosher's summary in the Scientific American:

...the self-assessment test, created in 1998 by psychiatrist Kimberly Young of Saint Bonaventure University in New York State, is an unofficial standard among Internet addiction researchers, and it consists of eight yes-or-no questions designed to separate online addicts from those who can manage their Internet use. (Questions range from, "Do you use the Internet as a way of escaping from problems or of relieving an anxious mood?" to "Have you taken the risk of losing a significant relationship, job, educational or career opportunity because of the Internet?".
Some further clips from that summary:
...another part of the new study on Internet addiction...zeroed in on white matter tissue deep in the brain which links together various regions. The scans showed increased white matter density in the right parahippocampal gyrus, a spot also tied to memory formation and retrieval. In the left posterior limb of the internal capsule, which is linked to cognitive and executive functions, white matter density dropped relative to the rest of the brain...The abnormality in white matter in the right parahippocampal gyrus may make it harder for Internet addicts to temporarily store and retrieve information, if a recent study is correct. Meanwhile, the white matter reduction in the left posterior limb could impair decision-making abilities—including those to trump the desire to stay online and return to the real world.

Tuesday, June 28, 2011

Ventromedial prefrontal cortex and judgement bias.

More from Reed Montague and colleagues in an open access article that further probes the role of the ventromedial prefrontal cortex in judgement bias:

Recent work using an art-viewing paradigm shows that monetary sponsorship of the experiment by a company (a favor) increases the valuation of paintings placed next to the sponsoring corporate logo, an effect that correlates with modulation of the ventromedial prefrontal cortex (VMPFC). We used the same art-viewing paradigm to test a prevailing idea in the domain of conflict-of-interest: that expertise in a domain insulates against judgment bias even in the presence of a monetary favor. Using a cohort of art experts, we show that monetary favors do not bias the experts’ valuation of art, an effect that correlates with a lack of modulation of the VMPFC across sponsorship conditions. The lack of sponsorship effect in the VMPFC suggests the hypothesis that their brains remove the behavioral sponsorship effect by censoring sponsorship-dependent modulation of VMPFC activity. We tested the hypothesis that prefrontal regions play a regulatory role in mediating the sponsorship effect. We show that the dorsolateral prefrontal cortex (DLPFC) is recruited in the expert group. Furthermore, we tested the hypothesis in nonexpert controls by contrasting brain responses in controls who did not show a sponsorship effect to controls who did. Changes in effective connectivity between the DLPFC and VMPFC were greater in nonexpert controls, with an absence of the sponsorship effect relative to those with a presence of the sponsorship effect. The role of the DLPFC in cognitive control and emotion regulation suggests that it removes the influence of a monetary favor by controlling responses in known valuation regions of the brain including the the VMPFC.

Monday, June 27, 2011

How our attention can be highjacked.

Here are some interesting observations by Anderson et al. on how our attention can be highjacked by stimuli irrelevant to the task at hand, causing failures of cognitive control.:

Attention selects which aspects of sensory input are brought to awareness. To promote survival and well-being, attention prioritizes stimuli both voluntarily, according to context-specific goals (e.g., searching for car keys), and involuntarily, through attentional capture driven by physical salience (e.g., looking toward a sudden noise). Valuable stimuli strongly modulate voluntary attention allocation, but there is little evidence that high-value but contextually irrelevant stimuli capture attention as a consequence of reward learning. Here we show that visual search for a salient target is slowed by the presence of an inconspicuous, task-irrelevant item that was previously associated with monetary reward during a brief training session. Thus, arbitrary and otherwise neutral stimuli imbued with value via associative learning capture attention powerfully and persistently during extinction, independently of goals and salience. Vulnerability to such value-driven attentional capture covaries across individuals with working memory capacity and trait impulsivity. This unique form of attentional capture may provide a useful model for investigating failures of cognitive control in clinical syndromes in which value assigned to stimuli conflicts with behavioral goals (e.g., addiction, obesity).

Friday, June 24, 2011

Debate on mechanisms for change..continued

My recent post pointing to David Brooks comments on the health care debate drew a number of spirited responses, and I though I would continue this thread by passing on this link to comments by Gary Gutting on clearly distinguishing facts versus convictions.

Does cognitive training work?

From Jaeggi et al., this open access article on their most recent cognitive training studies:

Does cognitive training work? There are numerous commercial training interventions claiming to improve general mental capacity; however, the scientific evidence for such claims is sparse. Nevertheless, there is accumulating evidence that certain cognitive interventions are effective. Here we provide evidence for the effectiveness of cognitive (often called “brain”) training. However, we demonstrate that there are important individual differences that determine training and transfer. We trained elementary and middle school children by means of a videogame-like working memory task. We found that only children who considerably improved on the training task showed a performance increase on untrained fluid intelligence tasks. This improvement was larger than the improvement of a control group who trained on a knowledge-based task that did not engage working memory; further, this differential pattern remained intact even after a 3-mo hiatus from training. We conclude that cognitive training can be effective and long-lasting, but that there are limiting factors that must be considered to evaluate the effects of this training, one of which is individual differences in training performance. We propose that future research should not investigate whether cognitive training works, but rather should determine what training regimens and what training conditions result in the best transfer effects, investigate the underlying neural and cognitive mechanisms, and finally, investigate for whom cognitive training is most useful.

Thursday, June 23, 2011

Why ketamine ( 'special K') makes you happy

I've mentioned in a previous post that the club drug K may be useful for something besides the psychedelic high of going "down the K-hole." Now
Science NOW points to an article from Monteggia and colleagues who find a new pathway that partially explains why the anti-depressant effects of low doses of ketamine (used at higher levels as an anesthetic and taken recreationally as a hallucinogen) start soon after it is taken, rather than requiring weeks, as with Zoloft or Paxil. Here is a clip from the Science summary:
...ketamine binds to, and blocks, a receptor in the brain called NMDAR, which triggers its anesthetic effects, so Monteggia's group used other compounds to block NMDARs in mice...the animals depression once again lessened, so the researchers knew that ketamine's antidepressant effects also depended on NMDAR. Next, the team studied how levels of certain proteins in the brain changed when mice were given ketamine. Blocking NMDARs with other compounds turns off production of some proteins, but ketamine causes the neurons to make more of a protein called BDNF (brain-derived neurotrophic factor)...The findings suggest a new set of molecules that ketamine and NMDAR affects, and that means a new set of molecules involved in depression.
...
There are two ways of activating NMDARs. Some turn on when the specific neurons fire to accomplish a task—be it learning, memorizing, or thinking. But other NMDARs are activated simply as background noise in the brain. Ketamine, the researchers showed, doesn't block the brain from activating NMDARs when it's using them to send a specific message. But it does block them from creating that background noise. Although scientists have long known about the brain's spontaneous level of background nerve firing, Monteggia's study is the first to suggest a link between such background noise and depression.

Wednesday, June 22, 2011

The visual impact of gossip

Here is an interesting bit from Anderson et al. Apparently hearing negative gossip about someone apparently activates top down brain filtering mechanisms that make it more likely that we will notice their face among conflicting stimuli:

Gossip is a form of affective information about who is friend and who is foe. We show that gossip does not influence only how a face is evaluated—it affects whether a face is seen in the first place. In two experiments, neutral faces were paired with negative, positive, or neutral gossip and were then presented alone in a binocular rivalry paradigm (faces were presented to one eye, houses to the other). In both studies, faces previously paired with negative (but not positive or neutral) gossip dominated longer in visual consciousness. These findings demonstrate that gossip, as a potent form of social affective learning, can influence vision in a completely top-down manner, independent of the basic structural features of a face.

Tuesday, June 21, 2011

Innate Euclidean geometry.

This report from Izard et al. is kind of neat:

Kant argued that Euclidean geometry is synthesized on the basis of an a priori intuition of space. This proposal inspired much behavioral research probing whether spatial navigation in humans and animals conforms to the predictions of Euclidean geometry. However, Euclidean geometry also includes concepts that transcend the perceptible, such as objects that are infinitely small or infinitely large, or statements of necessity and impossibility. We tested the hypothesis that certain aspects of nonperceptible Euclidian geometry map onto intuitions of space that are present in all humans, even in the absence of formal mathematical education. Our tests probed intuitions of points, lines, and surfaces in participants from an indigene group in the Amazon, the Mundurucu, as well as adults and age-matched children controls from the United States and France and younger US children without education in geometry. The responses of Mundurucu adults and children converged with that of mathematically educated adults and children and revealed an intuitive understanding of essential properties of Euclidean geometry. For instance, on a surface described to them as perfectly planar, the Mundurucu's estimations of the internal angles of triangles added up to ∼180 degrees, and when asked explicitly, they stated that there exists one single parallel line to any given line through a given point. These intuitions were also partially in place in the group of younger US participants. We conclude that, during childhood, humans develop geometrical intuitions that spontaneously accord with the principles of Euclidean geometry, even in the absence of training in mathematics.
Added note: Galina Miklosic has done a translation of this post into Ukrainian.

Monday, June 20, 2011

The amygdala - not command central for our fear reactions?

Most of us have accepted for years, starting from LeDoux's early work, that there is an automatic unconscious 'downstairs' rapid pathway in our brain that does our most important affective processing, before other more 'upstairs' cortical networks fill in the consciousness perceptual details. A recent review by Pessoa and Adolphs (PDF here) has offered a more nuanced view, from a 'low road' to 'many roads' model for our processing the significance of affective stimuli, in which the cortex plays a much larger role in processing affective visual information than is typically acknowledged. Part of their argument is based on recent studies showing that reaction times for detecting fearful faces in a patient with complete bilateral amygdala lesions were normal, a finding now extended to several further patients.

Here is the abstract of that review:
A subcortical pathway through the superior colliculus and pulvinar to the amygdala is commonly assumed to mediate the non-conscious processing of affective visual stimuli. We review anatomical and physiological data that argue against the notion that such a pathway plays a prominent part in processing affective visual stimuli in humans. Instead, we propose that the primary role of the amygdala in visual processing, like that of the pulvinar, is to coordinate the function of cortical networks during evaluation of the biological significance of affective visual stimuli. Under this revised framework, the cortex has a more important role in emotion processing than is traditionally assumed.
This review has triggered extensive commentary, and I wanted to pass on to those MindBlog readers who are into brain and emotion details PDFs of two letters outlining the issues, the critique from de Gelder et al., and the convincing and balanced (to me) response from Pessoa and Adolphs.

Article of the future...

I'm on the editorial board of one of the Elsevier journals, and so get occasional emails on things they are cooking up. Towards the end of 2011 they proclaim they will be changing what has been for 350 years the standard format of scientific articles. They offer online prototypes of their "Article of the Future," and here is their prototype for Psychology and Cognitive Science.

Looks to me like they are playing catchup with Cell Press and its associated Journals, such as Neuron, which has an interesting recent special issue on social neuroscience.

Friday, June 17, 2011

Why we laugh

In the June 10 issue of Science Walter Sinnott-Armstrong reviews what looks like a fascinating and fun book: "Inside Jokes Using Humor to Reverse-Engineer the Mind," by Matthew M. Hurley, Daniel C. Dennett, and Reginald B. Adams Jr. MIT Press, Cambridge, MA. (I just downloaded it to my Kindle.) The reviewer lays out their core theory:

The key to the authors' success is that they locate humor within recent cognitive science and evolutionary theory. To aid survival, our brains constantly and covertly use heuristics to generate expectations about what we will experience next, but we would be too inventive for our own good if we did not regularly search for and remove discrepancies between our expectations and our experiences. The immediate incentive to look for such discrepancies and thereby to reduce error comes from the pleasure of discovering a mistake in a currently harmless active belief that was introduced covertly. That pleasure is mirth, and humor is what produces it. Thus, humor is “a cognitive cleanup mechanism” that stains with mistaken belief before washing out the error (as in “I wondered why the Frisbee was getting bigger, and then it hit me.”). Laughter is then a public signal of our ability to clean up our minds. Because such cognitive prowess is useful, it attracts mates—both friends and sexual partners—and spreads throughout the world.

Hurley, Dennett, and Adams apply their theory to well over a hundred examples (including stupid jokes, dark humor, musical jokes, and witty remarks that are not humorous), to many apparent counterexamples (such as surprises, forgetting, riddles, and lies), and to related phenomena (such as magicians and garden-path sentences).

Thursday, June 16, 2011

Techie nirvana - Google's human android

I've gone for the cloud. On receiving an invitation (which I requested) from Google to try their beta version of Google Music (music.google.com) I've installed their music manager app which appears to be uploading my entire 23 GB iTunes library to their servers (from my university office with very high speed upload rate - much faster than would happen at home), playable from any web browser or android phone or tablet. Given how completely dependent I have become on Google's Calendar, Contact list, Mail, Phone, and Blogger applications that synch across my computers at three different locations, I have become a Google Humanoid Android (definition: Possessing human features. n. An automaton that is created from biological materials and resembles a human. Also called humanoid.) When the first really major terrorist cyber attack takes out the cloud, I will loose ego projections that have assumed almost as much importance in constituting my human self as my actual arms and legs. (Probably not, actually, since I'm writing this.)

Liszt - Années de pèlerinage - Vallee d'Obermann

This is the fourth piece played in a house concert for friends at my home on Twin Valley Road in Middleton WI, on May 22, 2011. This recording was made on June 13. The piece is from one of Liszt's three suites titled 'Years of Pilgrimage.' Obermann's Valley is from the Swiss suite which contains nine pieces written in 1848-1854. It has several romantic captions, one from Byron's Childe Harold's Pilgrimage ("Could I embody and unbosom now / That which is most within me,--could I wreak / My thoughts upon expression, and thus throw / Soul--heart--mind--passions--feelings--strong or weak-- …etc., ) and two captions from the French romantic writer Senancour's book Obermann, which includes questions like , “What do I want? Who am I? What do I ask of nature?" … This is a very histrionic and emotional piece.


The Empathetic Brain

Christian Keyser, who does research on mirror neurons at The Netherlands Institute for Neuroscience, sent me an email yesterday pointing out his new book on human empathy. My scan of the copy he sent to me finds the book to written in a friendly, engaging, and accessible style for a non-technical audience. I point it out here because it is available as a Kindle Book at Amazon, and the price is right ($3.00).

Wednesday, June 15, 2011

The quest for validation.

Out of the virtual diarrhea of commentary on Anthony Weiner's weiner, the commentary by Ross Douthat struck a chord with me, and so I muse a bit following these clips from his piece:

In the sad case of Representative Anthony Weiner’s virtual adultery, the Internet era’s defining vice has been thrown into sharp relief. It isn’t lust or smut or infidelity, though online life encourages all three. It’s a desperate, adolescent narcissism...his “partners” existed less to titillate him than to hold up mirrors to his own vanity...a growing body of research suggests that American self-involvement is actually reaching an apogee in the age of Facebook and Twitter.. In a culture increasingly defined by what Christine Rosen describes as the “constant demands to collect (friends and status), and perform (by marketing ourselves),” just being a United States congressman isn’t enough. You have to hit the House gym and look good coming out of the shower, and then find a Twitter follower who’s willing to tell you just “how big” you really are...Facebook and Twitter did not forge the culture of narcissism. But they serve as a hall of mirrors in which it flourishes as never before — a “vast virtual gallery,” as Rosen has written, whose self-portraits mainly testify to “the timeless human desire for attention.”
After feeling a bit superior reading this article about 'poor Anthony Weiner' I turn it around to try this as a description of myself. Why do I write this blog, why do I put effort into piano performance and posting the videos of recent playing? In my most lucid moments I genuinely feel that the "I-it" relationship is primary, my own personal experience of immersing myself in great ideas or great music, and then secondarily sharing this experience with others. But it is also the case that another Deric, the kid who showed up at 4th grade show-and-tell with his grandfather's dress U.S. Calvary sword to impress everyone, is a motive engine. So I also stand guilty as charged above. Still, "the timeless human desire for attention" is the inborn mechanism by which our brains grow and we become selves by mirroring and then internalizing the selves of others. To do this we must grab the attention of others, and thus have a desire to perform so that they will be impressed. At some point, however, we hope to have ourselves more or less together as adults, and let go off our earlier insatiable longing for validation. (It is not surprising that the most common outlets for remnants of this longing are real or imagined fantasies of sexual attractiveness.)

Tuesday, June 14, 2011

Shame and honor drive cooperation

In Biological Letters, an interesting and simple result from Jacquet et. al.:

Can the threat of being shamed or the prospect of being honoured lead to greater cooperation? We test this hypothesis with anonymous six-player public goods experiments, an experimental paradigm used to investigate problems related to overusing common resources. We instructed the players that the two individuals who were least generous after 10 rounds would be exposed to the group. As the natural antithesis, we also test the effects of honour by revealing the identities of the two players who were most generous. The non-monetary, reputational effects induced by shame and honour each led to approximately 50 per cent higher donations to the public good when compared with the control, demonstrating that both shame and honour can drive cooperation and can help alleviate the tragedy of the commons.

Monday, June 13, 2011

Debate on optimal mechanisms for political and social change

David Brooks has done what seems to me a balanced piece on the fundamental philosophical issues underlying the current debate on reform of entitlements, role of government,etc. I find myself less reflexively opposed to his conservative sympathies after reading his description of different strategies for effecting change. The basic issue boils down to "What is the best mechanism for effecting change in enormously complex social systems." Brooks, in the tradition of the British philosopher Oakeshott (seems to me he should have referenced his own essay on Oakeshott), thinks that decentralized bottom-up market based solutions are the best way to reform medical care, noting that

...competition-based plans (favored by Republicans) have improved outcomes in many places. Such plans cover employees of the University of California and state employees in California, Wisconsin and Minnesota. They also note that the Medicare prescription drug benefit also uses a competition model. Consumers have been adept at negotiating a complex marketplace, and costs are 41 percent below expectations.
The alternative (liberal, Democratic) view is that the best mechanism of change is top-down control that
...seeks to concentrate decision-making and cost-control power in the hands of centralized experts. Under the Obama health care law, a team of 15 officials will be created to discover best practices and come up with cost-cutting measures. There will also be a Center for Medicare and Medicaid Innovation in Washington to organize medical innovation. Centralized officials will decide how to set national reimbursement rates.
They argue that
Health care is phenomenally complicated. Providers have much more information than consumers. Insurance companies are rapacious and are not in the business of optimizing care.
Brooks:
...there is no dispositive empirical proof about which method is best — the centralized technocratic one or the decentralized market-based one. Politicians wave studies, but they’re really just reflecting their overall worldviews. Democrats have much greater faith in centralized expertise. Republicans (at least the most honest among them) believe that the world is too complicated, knowledge is too imperfect. They have much greater faith in the decentralized discovery process of the market.
So here we go, another either/or Manichean kind of presentation... maybe we should reference a biological model, take a lesson from how our brains organize our behavior, both from the bottom up AND from the top down, with feedback loops continually connecting the two.

Friday, June 10, 2011

Searching for the True Self

Joshua Knobe writes a piece for The Stone, a forum for contemporary philosopers in The New York Times Opinionator. The issue posed is:

...which aspect of a person counts as that person’s true self?

Many believe that the true self lies precisely in our suppressed urges and unacknowledged emotions...If we look to the philosophical tradition, we find a relatively straightforward answer to this question. This answer, endorsed by numerous different philosophers in different ways, says that what is most distinctive and essential to a human being is the capacity for rational reflection. A person might find herself having various urges, whims or fleeting emotions, but these are not who she most fundamentally is. If you want to know who she truly is, you would have to look to the moments when she stops to reflect and think about her deepest values.

...people outside the world of philosophy...are immediately drawn to the very opposite view. The true self, they suggest, lies precisely in our suppressed urges and unacknowledged emotions, while our ability to reflect is just a hindrance that gets in the way of this true self’s expression.
Knobe describes an 'experimental philosophy' experiment done with another colleague that presented a series of question to liberals and conservatives and found a systematic connection between people’s own values and their judgments about the true self. Conservative participants were more inclined to say that a person’s true self had emerged on conservative items, while liberals were more inclined to say that the person’s true self had emerged on liberal items.

Knobe has an appointment at Yale in both Cognitive Science and in Philosophy. He is a co-editor, with Shaun Nichols, of the volume “Experimental Philosophy.” Given his cognitive science appointment, I am struck that he doesn't bring up the question of whether "The True Self" is a viable concept at all, given what we now know about how our brains clearly construct not one, but a multitude of selves, all of which are essentially confabulations tested by their utility (see the sundry web lectures I list in the left column of this blog).

Thursday, June 09, 2011

A devolution of modern nation states?

I've been reading Fukayama's new book on the origins of political order and the evolution, first in England, of government with the three pillars of (1) The rule of law, (2) Strong central authority, and (3) Accountability of the leader. This is the form to which advanced modern nation states nominally adhere (even if they hold sham elections, are kleptocracies lacking rule of law, or have no check on central authority - think of Russia, China, former Soviet republics, or many African states.)

It strikes me that an consequence of the ultra-connectivity allowed by the internet may be a devolution of this nation state model, as an echo chamber mechanism allows people with different political or religious philosophies - the modern equivalent of the tribes that have dominated most of human history - to sequester themselves with like minded people reinforcing and making more extreme their world view. Thus we have phenomena like our current failure of U.S. governance as conservative and liberal camps appear to care more about their tribal agendas than the viability of the larger nation state. We seem to be moving in the direction of Afganistan or Iraq, where tribal loyalties are currently preventing the formation of effective modern nation states.

(Added note on 6/10/11 - Today's NYTimes has an interesting related piece by Roger Cohenwhich is well worth reading, from which I pull this quote:

...at a time of economic hardship, the movements in the West with momentum are nationalist — like Marine Le Pen’s National Front in France or the Tea Party movement in the United States. Tribe trumps technology’s integrative tug. But the engine of that tug is remorseless and will in time prevail.

Wednesday, June 08, 2011

Chopin Fantasy in F Minor

This is the third piece played in a house concert for friends at my home on Twin Valley Road in Middleton WI, on May 22, 2011. I'm doing just one run through of each of the pieces from that concert, this recording was made on June 3. I'm not patient enough to do the multiple takes that would be required to get a version without a section of scrambled notes happening at some unpredictable point.

Tuesday, June 07, 2011

Dopamine gene variants correlate with learning style.

In the Editor's choice section of the recent Science magazine Pamela Hines points to work by Kegel et al.:

Some children, particularly those with a more fearful temperament, are more sensitive than others to the influence of parents, teachers, and environment. Studying preschoolers, Kegel et al. attempt to link this with a particular genetic polymorphism. Children played a literacy-geared computer game that delivered instruction and assignments to all participants, but differed in whether it delivered feedback about the children's choices. A feature that distinguished the groups of children was whether they carried the long variant of the dopamine D4 receptor gene, which is associated with lower dopamine reception efficiency. Children who carried this polymorphism were more susceptible to the effects of feedback from the computer program. They outperformed the control group when feedback guided their learning, and they did worse than the control group when feedback was absent. In contrast, children with the short variant of the gene seemed to be unruffled by the presence or absence of feedback. For education, just as for shoes, a good fit to the individual produces the best result.
Here is the Kegel et al. abstract:
Not every child seems equally susceptible to the same parental, educational, or environmental influences even if cognitive level is similar. This study is the first randomized controlled trial to apply the differential susceptibility paradigm to education in relation to children's genotype and early literacy skills. A randomized pretest–posttest control group design was used to examine the effects of the Intelligent Tutoring System Living Letters. Two intervention groups were created, 1 receiving feedback and 1 completing the program without feedback, and 1 control group. Carriers of the long variant of the dopamine D4 receptor gene (DRD4 7-repeat) profited most from the computer program with positive feedback, whereas they performed at the lowest level of early literacy skills in the absence of such feedback. Our findings suggest that behind modest overall educational intervention effects a strong effect on a subgroup of susceptible children may be hidden.

Monday, June 06, 2011

A Haydn Fantasy

This Haydn Fantasy in C Major is the second piece performed in a house concert for friends on May 22, 2011. This recording was made on June 3, 2011 on my Steinway B at Twin Valley in Middleton Wisconsin.

Social influence undermines "The Wisdom of Crowds"

Interesting observations from Lorenz et al:

Social groups can be remarkably smart and knowledgeable when their averaged judgements are compared with the judgements of individuals. Already Galton [Galton F (1907) Nature 75:7] found evidence that the median estimate of a group can be more accurate than estimates of experts. This wisdom of crowd effect was recently supported by examples from stock markets, political elections, and quiz shows [Surowiecki J (2004) The Wisdom of Crowds]. In contrast, we demonstrate by experimental evidence (N = 144) that even mild social influence can undermine the wisdom of crowd effect in simple estimation tasks. In the experiment, subjects could reconsider their response to factual questions after having received average or full information of the responses of other subjects. We compare subjects’ convergence of estimates and improvements in accuracy over five consecutive estimation periods with a control condition, in which no information about others’ responses was provided. Although groups are initially “wise,” knowledge about estimates of others narrows the diversity of opinions to such an extent that it undermines the wisdom of crowd effect in three different ways. The “social influence effect” diminishes the diversity of the crowd without improvements of its collective error. The “range reduction effect” moves the position of the truth to peripheral regions of the range of estimates so that the crowd becomes less reliable in providing expertise for external observers. The “confidence effect” boosts individuals’ confidence after convergence of their estimates despite lack of improved accuracy. Examples of the revealed mechanism range from misled elites to the recent global financial crisis.

Friday, June 03, 2011

Antiinflammatory drugs oppose antidepressant drug action

Life just got much more complicated for doctors prescribing both antidepressant and anti-inflamatory drugs to the same patient. Greengard and colleagues have found a specific molecular pathway linking cytokines and the actions of antidepressant drugs. Their findings confound established wisdom, because they imply that brain cytokines exert antidepressant actions and mediate the influences of the principal serotonin-specific reuptake inhibitor (SSRI) antidepressant drugs. Doctors now should weigh the benefits of antiinflammatory agents against their possible lessening of the effectiveness of antidepressant drugs.

Anti-inflammatory drugs achieve their therapeutic actions at least in part by regulation of cytokine formation. A “cytokine hypothesis” of depression is supported by the observation that depressed individuals have elevated plasma levels of certain cytokines compared with healthy controls. Here we investigated a possible interaction between antidepressant agents and anti-inflammatory agents on antidepressant-induced behaviors and on p11, a biochemical marker of depressive-like states and antidepressant responses. We found that widely used anti-inflammatory drugs antagonize both biochemical and behavioral responses to selective serotonin reuptake inhibitors (SSRIs). In contrast to the levels detected in serum, we found that frontal cortical levels of certain cytokines (e.g., TNFα and IFNγ) were increased by serotonergic antidepressants and that these effects were inhibited by anti-inflammatory agents. The antagonistic effect of anti-inflammatory agents on antidepressant-induced behaviors was confirmed by analysis of a dataset from a large-scale real-world human study, “sequenced treatment alternatives to relieve depression” (STAR*D), underscoring the clinical significance of our findings. Our data indicate that clinicians should carefully balance the therapeutic benefits of anti-inflammatory agents versus the potentially negative consequences of antagonizing the therapeutic efficacy of antidepressant agents in patients suffering from depression.

Thursday, June 02, 2011

The echo chamber online.

Natasha Singer does an interesting article noting Eli Pariser's new book “The Filter Bubble: What the Internet Is Hiding From You,” and citing the opinions of several web gurus on how we are increasingly being encased in cocoons of information (passed through filters knowing our previous behavior) that reinforce our existing opinions and tastes.

Wednesday, June 01, 2011

Mozart - Fantasia in C Minor

Len and I held our annual Musical/Social at our Twin Valley Road home Sunday afternoon May 22. I performed this program for about 50 friends:

An afternoon of Fantasias:
Mozart - Fantasia in C Minor
Haydn - Fantasia in C Major
Chopin - Fantasy in F Minor
Liszt - Années de pèlerinage - Vallee d'Obermann
Debussy - Estampes III. Jardins sous la pluie

I did a video recording of the performance, but the conditions were not optimal, with background noises, etc.. so I am over the next period of time going to make a proper high quality audio recording of each of the pieces, synching it a video recording stripped of its lower quality sound. The upload of the first of these to YouTube is below, The Mozart Fantasia in C Minor.

“Representational rigidity” in our aging brains

Great...here we have Yassa et al. showing how a portion of the brain is doing what my knee joints are slowing doing, becoming more rigid with age. They look at the "place cells" in the hippocampus thought to be involved with discriminating between similar patterns. Long-term memory functions deteriorate with age, and the hippocampus, which play a role in learning new facts and remembering events, is one the sites that undergo the earliest changes.

Converging data from rodents and humans have demonstrated an age-related decline in pattern separation abilities (the ability to discriminate among similar experiences). Several studies have proposed the dentate and CA3 subfields of the hippocampus as the potential locus of this change. Specifically, these studies identified rigidity in place cell remapping in similar environments in the CA3. We used high-resolution fMRI to examine activity profiles in the dentate gyrus and CA3 in young and older adults as stimulus similarity was incrementally varied. We report evidence for “representational rigidity” in older adults’ dentate/CA3 that is linked to behavioral discrimination deficits. Using ultrahigh-resolution diffusion imaging, we quantified both the integrity of the perforant path as well as dentate/CA3 dendritic changes and found that both were correlated with dentate/CA3 functional rigidity. These results highlight structural and functional alterations in the hippocampal network that predict age-related changes in memory function and present potential targets for intervention.

MindBlog posts this summer.

With the arrival of the summer, and the start of my 11th year as an emeritus (i.e. retired) University of Wisconsin professor, I am wanting to relax the self-imposed obligation or drumbeat of a daily blog post. I am keenly aware of how my attentional capacities are slowly waning, as the number of little grey cells between the ears decreases. The time I spend scanning the tables of contents of various journals, reading a much larger number of articles than are mentioned in posts, and frequently settling for ‘good enough’ blog posts, is detracting from my getting into potential longer term personal and professional projects. So, for the next period of time, I'm going to spend less time cruising for material, and have a go at only posting what I come across that really strikes me.