Causality in the association between p300 and alpha event-related desynchronization

Abstract

Recent findings indicated that both P300 and alpha event-related desynchronization (alpha-ERD) were associated, and similarly involved in cognitive brain functioning, e.g., attention allocation and memory updating. However, an explicit causal influence between the neural generators of P300 and alpha-ERD has not yet been investigated. In the present study, using an oddball task paradigm, we assessed the task effect (target vs. non-target) on P300 and alpha-ERD elicited by stimuli of four sensory modalities, i.e., audition, vision, somatosensory, and pain, estimated their respective neural generators, and investigated the information flow among their neural generators using time-varying effective connectivity in the target condition. Across sensory modalities, the scalp topographies of P300 and alpha-ERD were similar and respectively maximal at parietal and occipital regions in the target condition. Source analysis revealed that P300 and alpha-ERD were mainly generated from posterior cingulate cortex and occipital lobe respectively. As revealed by time-varying effective connectivity, the cortical information was consistently flowed from alpha-ERD sources to P300 sources in the target condition for all four sensory modalities. All these findings showed that P300 in the target condition is modulated by the changes of alpha-ERD, which would be useful to explore neural mechanism of cognitive information processing in the human brain.