Possible influence of brain traveling waves on the reaction speed of subjects

Cortical traveling waves have been extensively studied and are documented across various experimental animal models and humans using both direct and indirect recording methods. They have been implicated in fundamental processes including perception, memory, decision-making, consciousness, and sleep. While these waves are readily interpretable in microelectrode recordings, their detection in MEG or EEG data presents significant challenges due to the volume conduction properties of the brain. In noninvasive recordings, traveling waves manifest as phase differences in oscillatory activity across recording channels. Here, we employed an algorithm to compute instantaneous phase differences, leveraging a unique feature of the Vector View system’s planar gradiometers—specifically, their orthogonal orientation (rotated 90° relative to one another). This approach enabled us to detect rotating dipoles beneath the recording sensors, indicative of traveling waves within the underlying cerebral sulci. Our study demonstrated that during auditory presentation of individual words, increased wave detection time within specific cortical regions correlates with either acceleration or deceleration of behavioral responses during word recognition.