Characteristics of left and right scanning in schizophrenia patients using exploratory eye movements: Comparison with healthy subjects


Kiichiro Morita, MD, Cognitive and Molecular Research Institute of Brain Diseases, Kurume University, 67, Asahi-machi, Kurume 830-0011, Japan. Email:


Abstract  To characterize the left and right scanning function and the effect of affection in schizophrenia patients exploratory eye movements as biologic markers were recorded in 44 schizophrenia patients and 72 age-matched healthy controls. The total eye scanning length (TESL) and total number of gaze points (TNGP) in the left and right visual fields were calculated as subjects viewed neutral or affectively charged pictures. TESL of patients was shorter than that of controls when viewing pictures of smiling babies and open circles. TESL of patients was shorter for smiling faces than for crying babies, but TESL of controls was longer for smiling faces than for crying babies. Left TNGP for smiling faces and circles was lower in patients than in controls. In patients, left TNGP for crying babies was higher than for either smiling babies or circles. In controls, left TNGP for smiling babies was higher than crying babies. In patients, left TNGP for smiling babies and circles was smaller than the right TNGP. In controls, left TNGP was larger for smiling than for crying babies. When viewing smiling babies, both TESL and TNGP were negatively correlated with negative symptom scores in patients. Patients' eye movements in the left visual field were clearly different from controls', suggesting that visual cognitive function is impaired in schizophrenia patients. Exploratory eye movements are a useful marker of visual cognitive function, and are a useful tool to evaluate the influence of affection in schizophrenia patients.