Impaired non-verbal emotion processing in Pathological Gamblers.

Impaired perception of emotion in others has been described and confirmed in addictions with substances, but no such data exists regarding addictions without substances. As it has been hypothesized that toxic effect of substances on the brain was responsible for the impairments described, studying addictions without substances could be of interest to confirm this hypothesis. Twenty-two male pathological gamblers were compared to 22 male healthy controls matched for age and education level on non-verbal emotion perception tasks including faces, voices, and musical excerpts. Depression and anxiety levels were controlled for. Pathological gamblers significantly underestimated the intensity of peacefulness in music, and overall they were less accurate when reading emotion in voices and faces. They also overestimated emotional intensity in neutral voices and faces. Although anxiety levels did account for accuracy problems when detecting fear in voices and for overestimating emotions in neutral faces, anxiety levels did not explain the range of deficits observed. This is the first study showing non-verbal perception deficits in a purely behavioural addiction. These findings show that deficits in decoding non-verbal signals are associated with addictive behaviours per se, and are not due solely to toxic effects of substances on the brain.