Altered emotional perception in alcoholics: deficits in affective prosody comprehension

Affective prosody is a nonlinguistic aspect of language that conveys emotion and attitude during discourse. It is a dominant function of the right hemisphere. Because skills associated with the right hemisphere have been found to be impaired in alcoholics, this study explored the possibility that affective prosodic functioning may be sensitive to the effects of alcohol due to heavy persistent drinking or prenatal exposure.

Subjects were aged 25 to 58 years. Twenty-nine men and three women who met DSM-IV criteria for an alcohol use disorder with a median of 39 days of sobriety, 11 men with a probable history of fetal alcohol exposure (FAexp), and 41 age-matched control subjects of both sexes were tested by using the Aprosodia Battery. This instrument assesses affective prosodic comprehension (APC) across a range of verbal articulatory demands.

The alcoholic group scored 2 SD below the control mean, and the FAexp group scored -5 SD regardless of whether they had ever been diagnosed with alcohol abuse. Despite their poor performance on APC, alcoholic and FAexp groups performed similarly to the control group on vocabulary, abstract reasoning, and an index of cognitive impairment that used the Shipley Institute of Living Scale. Multiple regression analyses that used nine alcohol use variables to model APC resulted in four significant contributors to the effect. These regressors were related to early exposure to ethanol and chronicity of alcohol abuse.

Alcoholics and FAexp subjects were significantly less accurate at APC compared with controls. These alcohol-exposed subjects appear to be deficient in the ability to understand emotional valence in the speech of others, which results in errors of judgment that may impair social interactions.