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 ERP old/new effects). One common problem across these studies concerns the observed ERP waveforms, which revealed a substantially weaker component structure (i.e., N1, N2, and particularly P3) in patients compared to controls, raising questions of comparable signal-to-noise ratios in the two study groups and the need for appropriate component measures that take into account ERP topography as a defining characteristic. Moreover, given the ambiguity as to whether the ERP repetition effect represents an electrophysiologic correlate of non-conscious memory retrieval processes (Friedman, 2000), and evidence that repetition priming effects – unlike recognition memory old/new effects – do not require intact MTL structures (Rugg et al., 1991), the findings for immediate item repetition, while interesting, provide limited electrophysiological evidence of impaired episodic memory in schizophrenia.
