Psychology Today: Pathological gambling: cerebral roulette - electroencephalogram research on compul

THE BRAIN Pathological gambling: Cerebral roulette

It's estimated that well over a million Americans can be classified as pathological gamblers, a condition that rivals alcoholism as a disrupter of careers, families and personal integrity. Although efforts to understand the roots of pathological gambling have traditionally focused on psychodynamic and social factors (see "Against All Odds," December 1985), researchers are beginning to look to the brain for additional clues to this disorder.

Neurobiologist Leonide Goldstein and colleagues at the New Jersey - Rutgers Medical School recruited eight healthy men with histories of pathological gambling, as well as a matched group of nongamblers. All were right-handed.

While an electroencephalogram (EEG) recorded electrical activity in their brains, the men completed a series of verbal and nonverbal tasks designed to activate either their left or right cerebral hemispheres. With their eyes closed, the men imagined either a scene (nonverbal, typically right-hemisphere-activating) or giving a speech or explaining a procedure (verbal, left-activating). With their eyes open, the men sorted nonsense shapes into groups (right-activating) or spelled simple words by arranging letters in a tray (left-activating).

As expected, the researchers report that the nongamblers' EEG's showed greater activity in the right hemisphere during the nonverbal tasks, and greater left-hemisphere activity during the verbal tasks. Not so with the gamblers. During the eyes-open procedure the commonly observed hemisphere specialization between verbal and nonverbal tasks was not as great. What's more, in the eyes-closed procedure, the relationship was actually reversed: that is, greater left-hemisphere activity for the nonverbal, commonly right-hemisphere task.

Goldstein and colleagues' findings with pathological gamblers parallel those of a similar study he and others conducted on children with attention deficit disorder (ADD). What makes this of "particular interest," they say, is the fact that pathological gambling, as well as alcoholism, is thought to result from problems in impulse control, a characteristic of children with ADD. And as other studies have documented a link between childhood ADD and later alcoholism in some people, the researchers tentatively suggest that "pathological gambling may share a common predispositional factor with alcoholism; that is, both . . . may be related to . . . the deficits in impulse control that characterize ADD." -- Laurence Miller Goldstein and colleagues reported their work in Biological Psychiatry (Vol. 20, pp. 1232-1234).