Briefs

In Scientific American (June 2002), News item "Double or Nothing" Charles Choi examines why gamblers often believe that after a string of losses they're due for a win.

Scientists now think they have pinpointed areas in the brain that are partly behind this kind of false thinking. Using functional magnetic resonance imaging, investigators at Duke University found a brain region that automatically looks for patterns, real or imagined. When volunteers were shown random sequences of circles and squares, blood flow increased to the prefrontal cortex, which is located just behind the forehead and is involved in memorization during moment-to-moment activity. This brain layer reacted whenever there were violations to apparent short-term patterns in the sequences--even though subjects knew that they were random.

Meanwhile researchers at the University of Michigan discovered that after losing a simple wager, volunteers were more likely to place larger, riskier bets if prompted to make another wager within a few seconds. Caps studded with electrodes revealed that when subjects learned they had won or lost wagers, electrical activity was highest in the medial frontal cortex, situated behind the prefrontal cortex. The Duke study appears online in the April 8 Nature Neuroscience; the Michigan work is in the March 22 Science.

See http://www.sciam.com/article.cfm?articleID=0008213E-305E-1CDC-B4A8809EC588EEDF&pageNumber=2&catID=2