Mixed emotions: alcoholics' impairments in the recognition of specific emotional facial expressions

Facial expression recognition is a central feature of emotional and social behaviour and previous studies have found that alcoholics are impaired in this skill when presented with single emotions of differing intensities. The aim of this study was to explore biases in alcoholics' recognition of emotions when they were a mixture of two closely related emotions. The amygdala is intimately involved in encoding of emotions, especially those related to fear. In animals an increased number of withdrawals from alcohol leads to increased seizure sensitivity associated with facilitated transmission in the amygdala and related circuits. A further objective therefore was to explore the effect of previous alcohol detoxifications on the recognition of emotional facial expressions. Fourteen alcoholic inpatients were compared with 14 age and sex matched social drinking controls. They were asked to rate how much of each of six emotions (happiness, surprise, fear, sadness, disgust and anger) were present in morphed pictures portraying a mix of two of those emotions. The alcoholic group showed enhanced fear responses to all of the pictures compared to the controls and showed a different pattern of responding on anger and disgust. There were no differences between groups on decoding of sad, happy and surprised expressions. In addition the enhanced fear recognition found in the alcoholic group was related to the number of previous detoxifications. These results provide further evidence for impairment in facial expression recognition present in alcoholic patients. In addition, since the amygdala has been associated with the processing of facial expressions of emotion, particularly those of fear, the present data furthermore suggest that previous detoxifications may be related to changes within the amygdala.