Impaired facial emotion perception of briefly presented double masked stimuli in violent offenders with schizophrenia spectrum disorders

Social interactions require decoding of subtle rapidly changing emotional cues in others to facilitate socially appropriate behaviour. It is possible that impairments in the ability to detect and decode these signals may increase the risk for aggression. Therefore, we examined violent offenders with schizophrenia spectrum disorders (SSD) and compared these with healthy controls on a computerized paradigm of briefly presented double masked faces exhibiting 7 basic emotions. Our hypotheses were that impaired semantic understanding of emotion words and low cognitive ability would yield lowest emotion recognition. SSD exhibited lower accuracy of emotion perception than controls (46.1% compared with 64.5%, p = 0.026), even when considering the unbiased hit rate (22.4% compared with 43%, Z = 2.62, p < 0.01). Raw data showed uncommon but significant misclassifications of fear as sad, disgust as sad, sad as happy and angry as surprise. Once guessing and presentation frequencies were considered, only overall accuracy differed between SSD and healthy controls. There were significant correlations between cognitive ability, antipsychotic dose, speed and emotion accuracy in the SSD group. In conclusion, that there were no specific emotion biases in the SSD group compared to healthy controls, but particular individuals may have greater impairments in facial emotion perception, being influenced by intellectual ability, psychomotor speed and medication dosages, rather than specifically emotion word understanding. This implies that both state and trait factors influence emotion perception in the aggressive SSD group and may reveal one source of potential misunderstanding of social situations which may lead to boundary violations and aggression.