Visual laterality patterns for the perception of emotional words in alcoholic and aging individuals

This study evaluated hypotheses concerning alcohol-related cerebral dysfunction: (1) alcoholism, like normal chronological aging, has a more detrimental effect upon functions controlled by the right hemisphere of the brain than functions controlled by the left hemisphere; (2) interhemispheric transfer dysfunction is associated with alcoholism and aging; and (3) alcoholism and aging act synergistically.

The participants were 61 right-handed men: 18 young (ages 30 to 49 years) and 14 older (50 to 69 years) detoxified abstinent alcoholics and 14 young and 15 older healthy nonalcoholic controls. In a perceptual laterality paradigm, emotional and nonemotional words were presented to the left or right visual fields, followed by a visual masking stimulus. The participants were asked to judge the emotional valence of each word (positive, negative or neutral) and to respond verbally or manually (button presses). The dependent variable was the Critical Interstimulus Interval needed to escape the backward-masking effect.

The alcoholics showed a significant right visual field advantage in both response mode conditions, whereas the controls did not. In addition, older alcoholics showed a selective impairment in processing negative words.

The findings support the suggestion that alcoholics may have deficient right-hemisphere functioning. Since both the young and older alcoholic groups showed similar right visual field advantages, the idea of synergism between alcoholism and aging with respect to perceptual asymmetries was not supported.