of targets, but was nevertheless correlated with the P300 response fluctuations across trials. This specific system was previously found to be related to P300 responses by Eichele and colleagues, who combined the ERP response at different latencies with the simultaneously acquired BOLD signals by means of a modified auditory oddball paradigm (Eichele et al., 2005). This result was also confirmed by our findings: the high spatial correlation between the maps of the dorsal attention network and the P300-BOLD correlation analysis is an indication that the P300 response fluctuations were modulated by brain intrinsic activity (Fox et al., 2006; 2007). This activity was suggested to be driven, to some extent, by behavioral conditions (Fox et al., 2007; Fox and Raichle, 2007). In particular the dorsal attention network was supposed to be influenced by voluntary attention shifts during search for salient stimuli (Shulman et al., 2003). Furthermore, other neuroimaging studies demonstrated that the activation of this specific network largely reflected sustained activity during continuous cognitive and behavioral tasks (Fox et al., 2005; Visscher et al., 2003), presumably related to adaptive task control (Dosenbach et al., 2007).
