at odds with prior reports of normal or even larger CRN amplitude in schizophrenic patients (e.g., Kopp and Rist 1999; Mathalon et al., 2002). However, a comparison of these findings may be difficult due to differences in experimental task and ERP methods, which apart from the CSD-PCA approach also include using a pre- rather than post-stimulus baseline for response-locked ERP activity to avoid the confound of subtracting stimulus-locked topographies (cf. Urbach and Kutas, 2006; Kayser et al., 2007). The presence of this component in healthy adults during these word recognition memory tasks is presumably an index of active performance monitoring to adaptively adjust response behavior in subsequent trials (Debener et al., 2005), and conversely, its reduction in schizophrenic patients reflects a dysfunction in effectively monitoring their ongoing response behavior (cf. Ullsperger, 2006), again impacting more severely on auditory information processing. These findings are consistent with evidence suggesting that a dysfunction of corollary discharge in schizophrenia, in which a failure to build internal representations of self-generated behavioral responses (efference copies) may be associated with, and specific to, auditory hallucinations (e.g., Ford et al., 2001, 2007; Ford and Mathalon, 2004; Mathalon and Ford, 2008).
