Brain Signals of Face Processing as Revealed by Event-Related Potentials

Figure 3

Time-frequency plots derived from wavelet transformations of multiple EEG trials in a subject. Induced activity in form of event-related spectral perturbation (ERSP (a)) and of the inter-trial phase coherence (ITC) as a measure of phase consistence among trials (b), both represented for recording sites Cz and Pz of the International 10/20 System and elicited in a face-feature matching task (see, e.g., [8]). Observe how induced activity (ERSP) is larger (red colour) in the middle of the epoch for low frequencies and around 200 msec for high ones. In turn, ITC is larger for very low frequencies along the epoch and for other somewhat higher oscillations at the beginning of the epoch.

(a)

(b)