A transient dominance of theta ERP component characterizes passive auditory processing: evidence from a developmental...

This study analyzed relationships among co-existent EEG frequency responses during passive auditory stimulus processing. By applying quantifiers based on wavelet entropy, it is demonstrated that a short-lasting ordering of the complex post-stimulus EEG signal occurs as a result of a transient synchronization in the theta frequency channel. Further, by using a developmental model it is shown that, independently of the frequency content of the background EEG and ERPs, a highly-ordered microstate in the ERP is always determined by theta frequency. Thus, transient dominance of synchronized theta oscillations may reflect an important functional mechanism subserving stimulus information processing.