Event-related modulation of alpha has been hypothesized to reflect inhibitory cortical control processing (e.g., Uhlhaas & Singer, 2010), with alpha desynchronization indicative of the release of cortical inhibition associated with a task-related coordinated activation of cortical networks (Klimesch et al., 2007). In this case, the reduced alpha ERD in schizophrenia and CHR patients may reveal cognitive deficits of top-down processing (Koh et al., 2011). Interestingly, another recent MEG study (Popov et al., 2012) found that alpha desynchronization normalized in schizophrenia after cognitive training and was associated with improved verbal memory performance. While it may be objected that impairments of alpha ERD were seen for both types of infrequent events, despite being more pronounced for the active response condition, successful performance on the current task involved responding to infrequent target tones and inhibiting a response to infrequent novel sounds, thereby demanding top-down attentional control for both types of events. Notably, these oscillatory deficits were not observed with ERP measures in the time domain, which are considered complementary to ERSP measures in the time-frequency domain (e.g., Makeig et al., 2002). Fittingly, no
