Left eye scanning deficit in schizophrenia patients under emotional loading task: comparison with healthy controls

The aim of the present study was to evaluate and characterize visual cognitive function and the effect of emotion in patients with schizophrenia.We recorded exploratory eye movements as biologic markers in 40 schizophrenic patients and 40 age-matched healthy controls. Total eye scanning length (TESL), total number of gaze points (TNGP), and TNGP in right (right TNGP) and left (left TNGP) visual fields on screen were calculated as subjects viewed affectively charged pictures (smiling and crying babies) with fitting sounds.TESL of patients was shorter than that of controls when viewing pictures of smiling babies while recalling pleasurable events, and significantly decreased under negative emotional loading when viewing crying babies while recalling sad events. TESL recovered to the original values after loading positive emotion again in the controls. However, TESL did not recover to the original values in schizophrenic patients. TNGP showed similar alterations in the emotional loading task. When TNGP was evaluated in left and right fields, in patients, the non-recovery of TNGP was only observed in the left side. TESL and left TNGP were negatively correlated with negative symptom scores on PANSS.Schizophrenic patients'eye movements in the left visual field screen during the emotional loading task were different from those of controls, which suggests that visual cognitive function is impaired in the right brain in schizophrenic patients. Exploratory eye movements are a useful marker of visual cognitive function, and are a useful tool to evaluate the influence of emotion in schizophrenic patients.