抄録
To study the mechanism of “octave illusion”, we measured auditory steady-state responses (ASSRs) with magnetoencephalography (MEG) evoked by tones that were amplitude-modulated at 38 Hz and 42 Hz with carrier frequencies of 440 (low tone) and 880 Hz (High tone). Binaural stimuli for the octave illusion (440→880→440Hz tone to the left ear, 880→440→880Hz tone to the right ear) and same pitch stimuli (440→880→440Hz tone to left and right ears) were used in the MEG experiments. As a result, the amplitude of ASSRs in bilateral temporal regions to the left-ear low tone and to the right-ear high tone was higher during the octave illusion stimuli than during same pitch stimuli. The ASSR in right temporal region to the low tone was also significantly increased. The results suggested the right ear dominance during the binaural octave illusion stimuli (low tone to the left ear and high tone to the right ear).