Chunk #41 — 4 Discussion — 4.2 EEG discriminating components during the P3 and around reaction time reveal a period of transition from externally driven task-related to internally-driven processing
As expected for EEG windows close to reaction time, we found BOLD correlates in several regions related to the button press. This included the motor areas of the left precentral and postcentral gyri, which is consistent with a right-handed button press and has previously been associated with P3 coupling in visual (Bledowski et al., 2004a, 2004b; Warbrick et al., 2009) and auditory (Benar et al., 2007) tasks. We also saw activations in the cerebellar vermis, which coordinates and monitors movement (Ghez and Fahn, 1985), and right cerebellum area VIIIb, which plays additional roles in motor control, coordination, and accurate timing of movements, and which has been particularly associated with right-handed finger tapping (Stoodley and Schmahmann, 2009; Stoodley et al., 2012).
