Thursday, January 17, 2008

Talks: Social Context, Art and Science, Neuroeconomics

In the last couple days, I've had the good fortune of attending three very different talks in the department and on campus.

Psychology Dept Colloquium:
The Role of Social Context in Adolescent Delinquency (Julia Dmitrieva)

This young researcher seems to be a star in the field of social psychology, though in her talk she hit on aspects of her research that would be interesting to just about anybody in the field of psychology: developmental, clinical, cognitive, and social...using standing social psychological self- and peer-report measures, neuroimaging, behavior genetics, and so on.

She spoke about her research on the way that social context, at various levels (family, peer, and neighborhood), interacts with adolescent decision-making in contributing to adolescent behavior and delinquency. She examines such environmental stressors as parental hostility and peer delinquency.She also brought in the role of one of the dopamine receptor genes (DRD4) and the dopamingergic pathways in the reward system of the ventral striatum, and the difference between the way that the short (4-repeat) allele and the long (7-repeat) allele expresses in interaction with environmental factors and relates to impulsivity measures.

She did a particularly good job at explaining what a 4-repeat versus 7-repeat allele means, how it comes about, how it works, and especially interesting was one graphic she had that showed the distribution of 4- versus 7-repeat alleles across the globe, making the (not necessary supported but interesting) suggestion that you find increasing proportions of the long allele as you follow migration pathways (e.g. lowest amounts are found in Eurasia/Middle East, with increasing proportions towards east Asia, and then North America with the highest amounts in South America)...suggesting that at some level and in certain environments, high levels of impulsivity can be adaptive.

Citation: J. Dmitrieva (under review) "Interaction between the DRD4 Gene and the Risk Exposure and Adolescent Delinquency, Impulsivity and Trait Anger"

USC Visions and Voices: The Arts and Humanities Initiative
Science, Art, and Society with K.C. Cole and Alan Alda

The USC Provost, C.L. Max Nikias has created this outstanding program called Visions and Voices, which highlights USC’s excellence in the arts and humanities. The initiative provides a unique, inspiring and provocative experience for all USC students, regardless of discipline, and challenges them to become world-class citizens who will eagerly make a positive impact throughout the world. (adapted from the mission statement of the program)

K.C. Cole is a science writer (who has authored several books, and wrote for years for the LA Times, among other publications) who is on faculty at the USC Annenberg School for Communication in the Journalism department. Alan Alda is a well-known actor, as well as science buff. The spoke about the relationship, and the similarities and differences between science and art. The name Richard Feynman came up several times, who I was introduced to in my 7th grade science class, when we had to read What Do You Care What Other People Think?
Alda pointed out that towards the end of his career, Feynman (who was involved in the Manhattan Project, and was instrumental in discovering what went wrong with the o-rings in the Challenger shuttle) was only interested in doing research that was fun and interesting to him. One example was Feynman noticing (in a Cornell cafeteria) that while a plate tossed into the air was rotating on one axis, it wobbled on a second axis with some sort of regularity. He devoted some several years to discovering what the relationship was between rotation and wobble. Cole responded noting that such discoveries which some people may have said "why is this important?" in the future may lead to important applications. For example, GPS Satellites rely on discoveries made by Einstein in both his general and special relativity theories. At the time, however, it wasn't clear how important those theories would become.

They talked about scientists and artists as both types of people who experiment, who discover, who work towards the common good. Scientists and artists both wonder about the world. They both work and work and work, with many failures along the way, until they uncover their goal, or their truth. It was a fascinating dialogue.

Psychology Dept. Colloquium:
Just Saying "No": Neuroeconomic Perspectives on Self-Control
(John Monterosso)

Another Psychology Department lunchtime colloquium, this time featuring a rising star of the cognitive neuroscience (particularly, decision neuroscience) world. He also spoke to a wide crowd, having something for the neuroimagers, the addiction researchers, the social psychologists, developmental psychologists, those studying decision neuroscience, risk and reward, and so on.

He spoke about delay discounting in human and animal models. The basic idea is that relative to rational maximization, humans are "temporally myopic." For example, we know that eating better will be good in the long run, but we are somewhat blind to that, and choose instead the double cheeseburger from Jack in the Box. That is, we devalue the long term reward as a function of its delay. He proposed a model such that Vd = Vi/(1+DK), where:
Vd = Value following delay
Vi = Immediate value
D = Length of delay
and K = discounting index. The model allows Vd and Vi to be inversely proportional, which makes sense.

Rats discount less than pigeons on the order of 3. Humans differ from rats by a factor of nearly 1 million. He examines this phenomenon using a smaller-sooner/larger-later model. Would you rather have $5 now or $10 next week? If you're addicted to cigarette smoke, would you rather have half a puff now or a full puff next week? Would you rather have $5000 now, or $10,000 next month? Animal models tend to show the same trend for the $5 version or the $5000 version. Humans are clearly more complex creatures, as many of us might opt for the smaller-sooner option when speaking in magnitude of $5, but I don't know anybody who wouldn't opt for the larger-later option when the magnitude is on the order of $10,000. Humans must call upon other resources, folk theories of inhibition, planning and thinking about consequences, and so forth.

He found that increased activity in the ventrolateral prefrontal cortex (not far from the region referenced here) corresponds with an increased preference for the larger-later reward...that is, reduced delay-discounting.

He went on to describe some of his other theories and related research regarding this sort of decision making, and I encourage anybody interested to do a search with his name on Pubmed or Google scholar and read some of his papers. In all, another fascinating talk.

Citation: Monterosso, J. et al (2007). Frontoparietal Cortical Activity of Methamphetamine-Dependent and Comparison Subjects Performing a Delay Discounting Task. Human Brain Mapping 28:383–393�.

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