Physiological responsivity to emotional pictures in schizophrenia

Schizophrenic patients are known to experience difficulties in emotional information processing, yet knowledge of their physiological responsivity to emotional stimuli is limited. The purpose of this study was to investigate the physiological reactions of schizophrenic patients to emotional stimuli. We presented pictures selected from the International Affective Picture System (IAPS) to patients and controls, while assessing their subjective evaluations in terms of valence and arousal scores and measuring their responses of heart rate (HR), breathing rate (BR), skin conductance level (SCL) and diastolic (DBP) and systolic blood pressure (SBP). For the analysis of the physiological data, three emotional picture categories were formed: positive (erotic content), negative (physical injuries) and neutral (landscapes). Patients and controls did not differ in their subjective evaluations of the pictures. Also, for both patients and controls, the SCL and DBP responses to positive emotional pictures were larger as compared to negative and neutral pictures. However, the patients did show significantly increased HR responses to the positive emotional pictures as compared to controls, possibly as a result of a decreased parasympathetic activity. Only for the BR response to the positive emotional pictures did we observe significant positive correlations with the PANSS scores. These first data suggest that altered physiological responsivity to emotional pictures in schizophrenia is limited to those with positive emotional content. Further studies will need to refine the dynamics of this stimulus category in relation to clinical state and medication effects.