Harrison, N. 1 , Meyer, G. 2 & Wuerger, S. 3
1 Liverpool Hope University
2 University of Liverpool
3 University of Liverpool
In a previous fMRI study we found significant differences in BOLD responses for congruent and incongruent semantic audiovisual action sequences (whole-body actions and speech actions) in bilateral pSTS, left SMA, left IFG and IPL. Here our main goal was to examine the time-course of these differences using event-related potentials (ERPs). A one-back task was performed while 128 channel EEG data was recorded. ERPs in response to congruent and incongruent audiovisual actions were compared to identify regions and latencies of differences. Responses to congruent and incongruent stimuli differed between 240 - 280 ms, 320 - 400 ms, and 400 - 700 ms after stimulus onset. A dipole analysis (BESA) revealed that the difference around 250 ms can be partly explained by a modulation of sources in the vicinity of the superior temporal area, while the responses after 400 ms are consistent with sources in inferior frontal areas. Our results are in line with a model that postulates early recognition of congruent audiovisual actions in the pSTS, perhaps as a sensory memory buffer, and a later role of the IFG, perhaps in a generative capacity, in reconciling incongruent signals.