The auditory-visual integration of anger is impaired in alcoholism: an event-related potentials study

Chronic alcoholism leads to impaired visual and auditory processing of emotions, but the cross-modal (auditory-visual) processing of emotional stimuli has not yet been explored. Our objectives were to describe the electrophysiological correlates of unimodal (visual and auditory) impairments in emotion processing in people suffering from alcoholism, to determine whether this deficit is general or emotion-specific, and to explore potential deterioration in the specific cross-modal integration processes in alcoholism.

We used an emotion-detection task, with recording of event-related potentials (ERPs), in which 15 patients suffering from alcoholism and 15 matched healthy control subjects were asked to detect the emotion (angry, happy or neutral) displayed by auditory, visual or auditory-visual stimuli. Behavioural performance and ERP data recorded between June 2005 and April 2006 were analyzed.

ERPs demonstrated that the deficit in alcoholism originates earlier in the cognitive stream than has previously been described (mainly P300), namely, at the level of specific face (N170) and voice (N2) perceptive processing. Moreover, while patients with alcoholism did not show impaired processing of happy and neutral audio-visual stimuli, they did have a specific impairment in the cross-modal processing of anger. A source location analysis was used to confirm and illustrate the results.

These results suggest that the specific deficit that people with alcoholism demonstrate in processing anger stimuli, widely described in clinical situations but not clearly identified in earlier studies (using unimodal stimuli), is particularly obvious during cross-modal processing, which is more common than unimodal processing in everyday life.