A few studies have investigated ERP old/new effects in schizophrenia, the typical behavioral finding being poorer task performance (recognition accuracy and response latency) in patients. In the context of a word detection task (button press response to animal names embedded in a series of unrelated words), Matsumoto et al. (2001) found a markedly reduced nose-referenced positivity in 20 schizophrenic patients to immediately repeated nontarget words (zero lag), peaking around 450 ms, whereas a 5-lag repetition delay revealed a smaller old/new effect and no group difference to targets. These results largely matched the reduced word ERP repetition effects in schizophrenia observed by Matsuoka et al. (1999). This research group also reported that reduced ERP repetition effects for words were more pronounced for schizophrenic patients with more severe formal thought disorder (Matsumoto et al., 2005). Similar reduced immediate ERP word repetition effects were described by Kim et al. (2004) for 14 schizophrenic patients in an explicit continuous recognition task using 21-channel, linked-mastoids recordings, and, in contrast to Matsumoto et al. (2001), a 5-lag repetition delay revealed essentially comparable group differences (i.e., reduced
