Chunk #43 — 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
BOLD fMRI literature historically has reported activations mainly in gray matter, partially due to the common practice of masking white matter during statistical analyses, but growing evidence supports the presence of white matter BOLD signals. This is particularly true when single-trial variability is modeled (Yarkoni et al., 2009). Here, our latent variability feature, the EEG single-trial discriminating component, revealed BOLD correlates in white matter regions. Since these activations were adjacent to sensorimotor regions, including right postcentral and precentral gyri and the left precentral gyrus, they are most closely related to the button press.
