Tuesday, May 27, 2008

Blogging as self-medication

Maybe I've found one of the reasons I do this blog (other than to keep me off the streets): An article by Jessica Wapner in the June issue of Scientific American discusses studies on the therapeutic value of blogging. Blogging is claimed to provide physiological benefits similar to those that have been shown for expressive writing (serving as a stress-coping mechanism, improving memory and sleep, and boosting immune cell activity.) Blogging may act as a "placebo for getting satisfied." The blogosphere offers an antidote to social isolation. (Checking out my 'mdbownds' YouTube video postings reveals that the Debussy Reverie video has been viewed 98,739 times and 157 comments made; this mindblog gets 500-600 visitors each day. While this is social connection, I totally don't know any of you people, except for a handful of friends.) I find fleeting virtual world contacts a pallid substitute for real life huggable friends, and sometimes fret that my time spent hunkering over a keyboard provides too convenient an excuse for the harder work of being a robust member of real (versus virtual) social groups.

Another reason for being gay?

Ever alert for the latest speculation on a possible biological basis for why I might be gay, I come across this little gem on fruitflies: genetic manipulation that enhances dopamine levels in males makes them more likely to court with other males.

Monday, May 26, 2008

A Chopin Nocturne...

Chopin Nocturne Op. 27 No. 2, recorded on my Steinway B at Twin Valley.

For your memorial day holiday hangover

Check out this article by Joan Acocella in the May 26 issue of The New Yorker, "A Few Too Many - Is there any hope for the hung over?"

Tones of Ancient Greece

I found this brief commentary from "Random Samples" in the May 16 issue of Science so interesting that I wanted to pass it on in its entirety:
The strings of a helikon, a gadget invented by Ptolemy to probe musical scales, sounded last week for the first time in almost 2 millennia at the University of Cambridge in the U.K....Andrew Barker, a musicologist at the University of Birmingham, U.K., built the instrument from a description in Harmonics, Ptolemy's 2nd century treatise on the mathematics of music. Ancient scholars considered the study of harmonics vital in understanding the mathematical rules that they believed governed the universe. He unveiled it as part of Cambridge's Science of Musical Sound Project.

Barker says the 1-meter-long wooden instrument with eight metal strings allows scientists to test "complete scales constructed on the basis of mathematical principles." The helikon creates different pitches with a calibrated sliding bridge, which can be inserted diagonally to shorten strings to different lengths. Strings can also be moved crosswise to raise or lower the range of pitches. Barker, who showed how the adjustments produce different intervals when the gadget is plucked, admits that it's not designed for musicmaking. Still, he says he was delighted that it worked at all.

Cambridge historian Torben Rees, a professional jazz singer, called Barker's presentation "a fascinating account of ancient thinking concerning harmonics." Music, he says, was regarded as "the sensible expression of the order of the cosmos. This conception of the universe … was essentially the birth of mathematical physics."

Most popular consciousness papers

Here is the list of the five most downloaded papers from the ASSC archive for April, 2008:
1. Destrebecqz, Arnaud and Peigneux, Philippe (2005) Methods for studying
unconscious learning. In: Progress in Brain Research. Elsevier, pp. 69-80.
1877 downloads from 23 countries. http://eprints.assc.caltech.edu/170/
2. Koriat, A. (2006) Metacognition and Consciousness. In: Cambridge handbook
of consciousness. Cambridge University Press, New York, USA. 1297 downloads
from 23 countries. http://eprints.assc.caltech.edu/175/
3. Dehaene, Stanislas and Changeux, Jean-Pierre and Naccache, Lionel and
Sackur, Jérôme and Sergent, Claire (2006) Conscious, preconscious, and
subliminal processing: a testable taxonomy. Trends in Cognitive Science, 10
(5). pp. 204-211. 880 downloads from 16 countries.
http://eprints.assc.caltech.edu/20/
4. Sagiv, Noam and Ward, Jamie (2006) Crossmodal interactions: lessons from
synesthesia. In: Visual Perception, Part 2 - Fundamentals of Awareness:
Multi-Sensory Integration and High-Order Perception. Progress in Brain
Research, Volume 155. Elsevier, pp. 259-271. 868 downloads from 13
countries. http://eprints.assc.caltech.edu/224/
5. Tsuchiya, Naotsugu and Koch, Christof (2005) Continuous flash suppression
reduces negative afterimages. Nature Neuroscience, 8 (8). pp. 1096-1101. 762
downloads from 13 countries. http://eprints.assc.caltech.edu/35/

Friday, May 23, 2008

Are you a morning person? - mood and body clocks

From from PJH at editor's choice, Science Magazine.
Some neurotransmitters, such as dopamine, have been implicated in adjusting a person's mood. The circadian clock mechanisms, meanwhile, keep the organism's physiology tuned for appropriate responses to day or night. Hampp et al. have demonstrated how the molecular signaling pathways for circadian rhythms might intersect with the brain's establishment of general mood. They found that the promoter of the gene encoding monoamine oxidase A (Maoa), which stabilizes some aspects of mood and breaks down dopamine and serotonin, contains binding sites for several clock proteins and showed that circadian oscillation was driven by the Maoa promoter in neuroblastoma cells. Mice lacking Per2, a gene that stabilizes circadian rhythms, showed damped expression from the Maoa promoter. Observations of the Per2 mutant mice in response to an unavoidable problematic situation--taken as a proxy for despair in humans--showed correlations with disorders of mood.

Tranquility...

A MindBlog reader suggests that I pass along this link on "50+ Simple 30-Second Ways to Bring Tranquility To Your Life"... Hmmmm, good luck.

Thursday, May 22, 2008

Brain imaging of belief, disbelief, and uncertainty

A fascinating fMRI study by Sam Harris and colleagues has used functional magnetic resonance imaging (fMRI) to study the brains of 14 adults while they judged written statements to be true (belief), false (disbelief), or undecidable (uncertainty). (Yes, this is the same Sam Harris who wrote "The End of Faith" and "Letter to a Christian Nation."). To characterize belief, disbelief, and uncertainty in a content-independent manner, they included statements from a wide range of categories: autobiographical, mathematical, geographical, religious, ethical, semantic, and factual. They show that belief, disbelief, and uncertainty are mediated primarily by regions in the medial PFC, the anterior insula, the superior parietal lobule, and the caudate. The acceptance and rejection of propositional truth-claims appear to be governed, in part, by the same regions that judge the pleasantness of tastes and odors.
...the final acceptance of a statement as true or its rejection as false appears to rely on more primitive, hedonic processing in the medial prefrontal cortex and the anterior insula. Truth may be beauty, and beauty truth, in more than a metaphorical sense, and false propositions may actually disgust us.
...When compared with both belief and uncertainty, disbelief was associated in our study with bilateral activation of the anterior insula..., a primary region for the sensation of taste. The anterior insula has been regularly linked to pain perception and even to the perception of pain in others. This region, together with left frontal operculum (also active in the contrast disbelief - belief), appears to mediate negatively valenced feelings such as disgust. Studies of olfaction have shown that the left frontal operculum is engaged when subjects are required to make active judgments about the unpleasantness of odors. Thus, regions that have been regularly implicated in the hedonic appraisal of stimuli, often negative, appeared in our study to respond preferentially when subjects rejected written statements as false. Our results appear to make sense of the emotional tone of disbelief, placing it on a continuum with other modes of stimulus appraisal and rejection.
...Several psychological studies appear to support Spinoza’s conjecture that the mere comprehension of a statement entails the tacit acceptance of its being true, whereas disbelief requires a subsequent process of rejection...Understanding a proposition may be analogous to perceiving an object in physical space: We seem to accept appearances as reality until they prove otherwise...subjects assessed true statements as believable faster than they judged them as unbelievable or undecidable. Further, because the brain appears to process false or uncertain statements in regions linked to pain and disgust, especially in judging tastes and odors, this study gives new meaning to a claim passing the “taste test” or the “smell test.”

Wednesday, May 21, 2008

MindBlog becomes a drop-out student at a brain enhancement site

When the folks at happy-neuron.com offered me a free log in to check out their brain enhancement/preservation exercises I said "Sure, I'll try it out and do a review." The site offers a brief discussion of the science of brain fitness is offered, and the scientific contributors have reasonable credentials. Several have associations with gerontology and aging programs, as is the case with other brain enhancements sites. The single study I was pointed to testing the effects of the happy-neuron exercises was a pilot effort carried out by Robert Bender, a geriatrics and family practice physician in Des Moines, Iowa. He did not respond to my email requesting information on the study.

Well.... to do a proper review one really has to get into it, and I tried, but simply was unable to do this. One could just pick directly from ~ 35 classic style tests (of memory, attention, language, executive function, and visual spatial skills) with a thin video game veneer, or let a "coach" present you with 20 minutes worth of exercises. I chose the "coach" option which chooses exercises for you, monitors your progress, strengths and weaknesses, etc. (It didn't tell me what my strengths and weaknesses were, but perhaps I didn't stick with it long enough for it to get back to me...) The exercises were mildly engaging and indeed left me feeling 'brain tired' after 20 minutes. I did get a bit tired of variations on the towers of Hanoi game (classic form, then basket balls in hoops, then bells in cathedral towers, etc.) I found the 'exit' or 'next' buttons sometimes blanked out or froze the browser window.

I found it difficult to get hooked on the system in a daily basis (I came along before the video game revolution on which my kids were raised). The exercises soon took on an "eat your spinach" aspect. I suspect my motivation might have been greater to pursue them if had been accumulating more striking evidence of my own impending cognitive decline.

I did find it very interesting to pursue the exercises to the point of brain fatigue, which my brain was clearly saying "enough of this, dammit, I'm tired." However, I have not found exercise to the point of fatigue useful or relevant in the daily gym routine to which I am addicted (varying combinations of running, swimming, weights at the Univ. of Wisconsin gym). I feel it would take a similar sort of addiction process to bind me to the routine performance of games like these, and I did not get reinforcement from the "coach" that might have nudged me in that direction ("Hey, you're doing great on executive function and rotating visual images, but your short term memory sucks...")

I may continue to putter with this as well as other brain exercise sites, and if lightning strikes and I get enthusiastic, I'll report back to you.

An aging guide...

Check out the guided tour provided by the NY Times Well.

Tuesday, May 20, 2008

MRI - the new phrenology

Having just done a posting on MRI, I thought it appropriate to point to a discussion by Michael Shermer in his "Skeptic" column in the Scientific American on the misuse and over-interpretation of MRI data.

It is a reminder that seeing scans with highlighted (usually in red) areas where your brain “lights up” when thinking about X (money, sex, God, and so on) should not seduce us into buying the Swiss Army knife model of the brain, with specialized modules for vision, language, facial recognition, cheating detection, risk taking, spirituality and even God. There is the minor problem of reversing the causal inference:
...where people see some activity in a brain area and then conclude that this part of the brain is where X happens. We can show that if I put you into a state of fear, your amygdala lights up, but that doesn’t mean that every time your amygdala lights up you are experiencing fear. Every brain area lights up under lots of different states. We just don’t have the data to tell us how selectively active an area is.
As Patricia Churchland points out:
Mental modules are complete nonsense. There are no modules that are encapsulated and just send information into a central processor. There are areas of specialization, yes, and networks maybe, but these are not always dedicated to a particular task.” Instead of mental module metaphors, let us use neural networks.

The MRI of morality?

Greg Miller reviews research on the nature of human morality which continues to probe the debate between the views of of David Hume - that emotions drive moral judgments - and Immanuel Kant - who argued that reason should be the driving force. He includes reference to a recent study by Hsu, Anen, and Quartz on equity and efficiency. Some clips, from from the Miller review, and then the Hsu et al paper:

One research group:
...asked dozens of college students to consider several morally charged situations. In one, a friend lies on his résumé to land a job; in another, survivors of a plane crash consider cannibalizing an injured boy to avoid starvation. Students who pondered these hypothetical scenarios while sitting at a filthy desk with sticky stains and a chewed-up pen rated them as more immoral than did students who sat at a pristine desk. In another version of the experiment, a nearby trash can doused with novelty fart spray had a similar effect. The findings...demonstrate that emotions such as disgust exert a powerful influence on moral judgments, even when they are triggered by something unrelated to the moral issue.
Hsu et al. consider distributive justice, illustrated by the following example:
Imagine driving a truck with 100 kg of food to a famine stricken region. The time it would take you to deliver food to everyone would cause 20 kg of food to spoil. If you delivered food to only half the population you would lose only 5 kg. Do you deliver the food to only half the population to maximize the total amount of food, or do you sacrifice 15 kg to help everyone and achieve a more equitable distribution?
They examine the the tradeoff between equity and efficiency, finding:
...that the putamen responds to efficiency, whereas the insula encodes inequity, and the caudate/septal subgenual region encodes a unified measure of efficiency and inequity (utility). Strikingly, individual differences in inequity aversion correlate with activity in inequity and utility regions. Against utilitarianism, our results support the deontological intuition that a sense of fairness is fundamental to distributive justice, but, as suggested by moral sentimentalists, is rooted in emotional processing. More generally, emotional responses related to norm violations may underlie individual differences in equity
considerations and adherence to ethical rules.

Neuroimaging studies have linked several brain regions to moral cognition. Disruptions to the right temporoparietal junction (brown), which is involved in understanding intentions, or the ventromedial prefrontal cortex (green), which processes emotion, have been found to alter moral judgments... activity in the anterior cingulate cortex (pink) may signal conflict between emotion, reflected by activity in the medial frontal gyrus (blue) and other areas (orange, brown), and "cold" cognition, reflected by activity in dorsolateral prefrontal cortex (yellow).

Monday, May 19, 2008

Some Chopin to start the week...

I'm warming up to do some recordings this spring and summer.... this is Chopin's Nocture Op. 9 No. 1

Lacking power diminishes cognitive function

An implication of meritocracies is that individuals who lack power are low achievers because they are less capable or less motivated than those who acquire power. Smith et al. propose, alternatively, that powerless people often achieve less than powerful people because lacking power itself fundamentally alters cognitive functioning and increases vulnerability to performance decrements during complex executive tasks.

In a experiment carried out on 101 Dutch university students, simply assigning each participant to be either a superior or a subordinate in a computer-based task altered their performance on tests of executive function. (Participants were told that the superior would direct and evaluate the subordinate. This evaluation would purportedly determine the subordinate's payment for the experiment, whereas the superior would be paid a fixed amount.) Smith et al. found that the powerless were less effective than the powerful at standard tests evaluating ability to update, inhibition, and planning. Because existing research suggests that the powerless have difficulty distinguishing between what is goal relevant and what is goal irrelevant in the environment, a further experiment was carried out to establish that the executive-function impairment associated with low power is driven by goal neglect.

This work consistent with the idea that the cognitive alterations arising from powerlessness may help foster stable social hierarchies. The results also have implications for management and organizations. In many industries (e.g., health care, electric power), errors can be costly. Increasing employees' sense of power could lead to improved executive functioning, decreasing the likelihood of catastrophic errors.

Friday, May 16, 2008

Rapid orienting to positive, as well as negative, emotional stimuli.

Most of the work on how emotions focus our attention has focused on negative stimuli (snakes, angry faces, etc.) Brosch et al. use ERP measurement to note that our attention also can very reliably be captured by positive nurturance stimuli such as baby faces. The results confirm that biological relevance, and not exclusively fear, produces an automatic spatial orienting toward the location of a stimulus. From the paper:
...we recorded event-related potentials from 20 subjects performing a dot-probe task in which the cues were fear-inducing and nurturance-inducing stimuli (i.e., anger faces and baby faces). Highly similar validity modulation was found for the P1 time-locked to target onset, indicating early attentional capture by both positive and negative emotional stimuli. Topographic segmentation analysis and source localization indicate that the same amplification process is involved whether attention orienting is triggered by negative, fear-relevant stimuli or positive, nurturance-relevant stimuli.

Illustration of the experimental sequence. Each trial started with a fixation cross. Then the cue, consisting of two images presented on the left and right sides of the screen, was presented briefly. One of the two pictures was an emotional face, and the other was a neutral face. Following offset of the face pair, the fixation cross was presented randomly for 100, 150, 200, 250, or 300 ms. Afterward, the target, a triangle pointing upward or downward, appeared for 150 ms in the location of one of the previously presented faces. In a valid trial, the triangle was in the location of the emotional image; in an invalid trial, the triangle was in the location of the neutral image. Some participants were required to respond if the triangle pointed upward, and the others were required to respond if the stimulus pointed downward. SOA = stimulus onset asynchrony.

Thursday, May 15, 2008

Our facial touch sensitivity - enhanced by viewing a touch.

Studies have shown that observing touch on another person's body activates brain regions involved in tactile perception, even when the observer's body is not directly stimulated. Previous work has shown that in some synaesthetes, this effect induces a sensation of being touched. Serino et al. show in nonsynaesthetes, that
..when observers see a face being touched by hands, rather than a face being merely approached by hands, their detection of subthreshold tactile stimuli on their own faces is enhanced. This effect is specific to observing touch on a body part, and is not found for touch on a nonbodily stimulus, namely, a picture of a house...Thus, observing touch can activate the tactile system, and if perceptual thresholds are manipulated, such activation can result in a behavioral effect in nonsynaesthetes.The effect is maximum if the observed body matches the observer's body.

Figure - Visual stimuli used in the tactile confrontation task. In blocked trials, subjects viewed an image of their own face, another person's face, or a house. In each trial, the finger on the bottom left, the finger on the bottom right, or both fingers moved toward the target; in the touch condition, the finger (or fingers) actually touched the target, and in the no-touch condition, the finger (or fingers) reached a position 5 cm away from the target.
Think of when you might have watched a romantic touch in a movie, sitting next to someone you wished would stroke you.....

Wednesday, May 14, 2008

Brain monoamine oxidase activity predicts male aggression

Here is an edited version of the abstract from Alia-Klein et al.:
The genetic deletion of monoamine oxidase A (MAO A), an enzyme that breaks down the monoamine neurotransmitters norepinephrine, serotonin, and dopamine, produces aggressive phenotypes across species. In humans, studies provide evidence linking the MAOA genotypes and violent behavior but only through interaction with severe environmental stressors during childhood. The authors asked whether in healthy adult males the gene product of MAO A in the brain, rather than the gene per se, would be associated with regulating the concentration of brain amines involved in trait aggression. They measured brain MAO A activity was measured in vivo in healthy nonsmoking men with positron emission tomography using a radioligand specific for MAO A. Trait aggression was measured with the multidimensional personality questionnaire (MPQ). They show for the first time that brain MAO A correlates inversely with the MPQ trait measure of aggression (but not with other personality traits)...the lower the MAO A activity in cortical and subcortical brain regions, the higher the self-reported aggression (in both high and low MAO A genotype groups) contributing to more than one-third of the variability. Trait aggression is a measure used to predict antisocial behavior, and thus these results underscore the relevance of MAO A as a neurochemical substrate of aberrant aggression.

Tuesday, May 13, 2008

The Neural Buddhists

Check out the David Brooks OpEd piece with the title of this post. You really have to respect Brooks for putting so much energy into understanding contemporary mind science.
...the self is not a fixed entity but a dynamic process of relationships. Second, underneath the patina of different religions, people around the world have common moral intuitions. Third, people are equipped to experience the sacred, to have moments of elevated experience when they transcend boundaries and overflow with love. Fourth, God can best be conceived as the nature one experiences at those moments, the unknowable total of all there is...In their arguments with Christopher Hitchens and Richard Dawkins, the faithful have been defending the existence of God. That was the easy debate. The real challenge is going to come from people who feel the existence of the sacred, but who think that particular religions are just cultural artifacts built on top of universal human traits. It’s going to come from scientists whose beliefs overlap a bit with Buddhism...In unexpected ways, science and mysticism are joining hands and reinforcing each other. That’s bound to lead to new movements that emphasize self-transcendence but put little stock in divine law or revelation. Orthodox believers are going to have to defend particular doctrines and particular biblical teachings. They’re going to have to defend the idea of a personal God, and explain why specific theologies are true guides for behavior day to day. I’m not qualified to take sides, believe me. I’m just trying to anticipate which way the debate is headed. We’re in the middle of a scientific revolution. It’s going to have big cultural effects.

Your sexy voice and your hormones.

I'm passing this on to you, despite the fact that this gem went straight from the NY Times to the maw of the John Stuart Daily News/Colbert Report machine within one day... a women's voice becomes more seductive during ovulation, possibly because the larynx changes both its shape and size in response to reproductive hormones.
...The researchers recorded voice samples from about 50 undergraduate women at four times in their menstrual cycle. Then they asked 34 men and 32 women to listen to the recordings and rate them in terms of attractiveness...On the surface, the recordings were not terribly sexy. The women were asked to count from 1 to 10. But they must have been doing something different when they were closest to ovulating, because that was when they received the highest ratings, the researchers said.
So, I wonder if something similar happens in guys who are juiced when their testosterone levels increase?