Neuromagnetic auditory cortex responses to duration and pitch changes in tones: cross-linguistic comparisons of human subjects in directions of acoustic changes.
Our recent magnetic mismatch field (MMF) study found that shortened-vowel duration changes and level-to-falling pitch changes in Japanese words elicited a prominent MMF in two hemispheres for both native and nonnative speakers (Inouchi, M., Kubota, M., Ferrari, P. and Roberts, T.P.L., Magnetic mismatch fields elicited by Japanese words: vowel duration and pitch by native and nonnative speakers, Poster presented at the 31st Annual Meeting of Society for Neuroscience, November 10-15, San Diego, CA, 2001). The current study investigated whether shortened duration changes and level-to-falling pitch changes in non-speech (tones) would elicit a more prominent MMF component than lengthened duration changes and falling-to-level pitch changes, respectively. Stimuli included three computer-synthesized tones with varying duration or frequency modulation: (1). short duration and level pitch; (2). long duration and level pitch; (3). long duration and falling pitch. Magnetoencephalography responses were recorded with a dual 37-channel gradiometer system. The results showed that the prominent MMF component was generated in long-to-short duration changes and level-to-falling pitch changes in each hemisphere for both Japanese and American subjects. The component peaked at around 100 ms after change onset for duration changes and 170 ms for pitch changes. The MMF component in tones, like in words, was particularly sensitive to duration shortening and pitch falling. In summary, changes in duration shortening and pitch falling are particularly salient cues for pre-attentive auditory change detection in each hemisphere.
D000328:Adult; D001301:Audiometry, Pure-Tone; D001303:Auditory Cortex / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007564:Japan; D008037:Linguistics; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D010898:Pitch Perception / Q000502:physiology*; D013997:Time Factors