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

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 th e complex post-stimulus EEG signal occurs as a result of a transient synchr onization in the theta frequency channel. Further, by using a developmental model it is shown that, independently of the frequency content of the back ground EEG and ERPs, a highly-ordered microstate in the ERP is always deter mined by theta frequency. Thus, transient dominance of synchronized theta o scillations may reflect an important functional mechanism subserving stimul us information processing. NeuroReport 12:2791-2796 (C0 2001 Lippincott Wil liams & Wilkins.