Effect of subject's family name on visual event-related potential in schizophrenia

Visual event-related potentials (ERPs) were recorded from 15 schizophrenics and 15 age-matched and gender-matched controls, while they performed a modified version of the oddball paradigm. Each subject was required to detect target stimuli among a random sequence of stimuli under two conditions, name and color. In the name condition the stimulus sequence consisted of the subject's family name (deviant 18%), four other family names (standard 73%), and a city name (target 9%). In the color condition the respective stimuli were a pair of solid red circles, four white paired-arrows, and a pair of white plus and minus signs. ERPs elicited by stimuli contained triphasic potentials of P2, N2, and P3. In controls these waves were selectively enhanced for the subject's family name as compared with standards, whereas in schizophrenics no significant difference between the subject's family name and other names was observed. In contrast, selective enhancement for color deviants was observed in both subject groups. These results suggest that impairment of involuntary attention, especially for familiar and significant stimuli such as names in daily life, may underlie disturbances of attentionally controlled central processing in schizophrenia.