The ICA decomposition of the ERP data evidenced five ERP-ICs with different spatial and temporal profiles, accounting for the event-related responses. For each of them, the time-courses related to the rare and frequent events, the sensor map and the bar plot of the source power z-scores in the task-related network areas were estimated (Figure 4). The results obtained with the use of fMRI priors seemed to resolve the contribution of the ERP-ICs to the different networks [Liu et al., 1998]. In particular, the contribution of the visual areas could be clearly detected. We observed that the visual network was mostly involved in sensory processing, with a response at about 90 ms; the core network showed a response between 200 and 250 ms (P2 component), that could be related to task monitoring [Dosenbach et al., 2006]; the ventral attention network showed brain responses between 280 and 350 ms (P3 component), that could be ascribed to change detection and related memory processes [Corbetta and Shulman, 2002].
