A recent study employed this new approach for an improved characterization of modality-specific old/new effects in schizophrenia (Kayser et al., 2009). Stimulus- and response-locked 31-channel ERPs were recorded from 20 schizophrenic patients and 20 closely-matched healthy adults during auditory and visual continuous word recognition memory tasks. For visually-presented words, the study essentially replicated our previous findings (Kayser et al., 1999), clarifying that poorer recognition memory performance in patients was accompanied by reduced left lateral parietal, but not mid-parietal, P3 sources and reduced superimposed old/new effects, peaking about 150 ms before the response. Whereas auditory stimuli produced an ERP/CSD component structure and topographies markedly distinct from the visual task (cf. Kayser et al., 2003, 2007), late left lateral parietal old/new effects were even more reduced in schizophrenia for spoken words. This modality-dependent reduction of the late old/new effect in schizophrenia suggests a specific impairment of temporal integration and retrieval of semantic information by means of a phonological code (Baddeley, 1983), involving left parietal-temporal regions typically associated with language-related processing. This agrees with the hypothesis that receptive language dysfunction in schizophrenia is caused by a core deficit in the temporal dynamics of brain function (Condray, 2005).
