Intermanual differences on motor and psychomotor tests in alcoholics: no evidence for selective right-hemisphere dysfunction.

Some previous studies have suggested that alcoholics exhibit selective right-hemisphere dysfunction, based on alcoholics' poor performance on tests believed to subserve the right hemisphere. However, some of these experiments did not account adequately for differences in difficulty or novelty in putative right hemisphere tasks. This experiment was designed to evaluate and compare intermanual differences in grip strength, motor speed, fine-motor dexterity, and nonverbal problem-solving ability in 93 recently detoxified alcoholics, 54 long-term abstinent alcoholics, and 73 nonalcoholic controls. All subjects were right-handed men, matched for age and education, and both alcoholic groups had similar drinking histories. Using percent difference scores to assess intermanual differences, adjusted for demographics where appropriate, we found that, although recently detoxified alcoholics demonstrate some motor and psychomotor impairments, there is no evidence using these tests to suggest the right hemisphere is selectively more vulnerable to the effects of chronic alcohol abuse.