Auditory-visual speech processing -elucidation of its brain mechanisms, pathologies and plastic changes-

2015 Fiscal Year Final Research Report

• Project/Area Number: 24390386
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Tohoku University
• Principal Investigator: Kawase Tetsuaki 東北大学, 医工学研究科, 教授 (50169728)
• Co-Investigator(Kenkyū-buntansha): NAKASATO NOBUKAZU 東北大学, 大学院医学系研究科, 教授 (80207753) ; KANNO AKITAKE 東北大学, 加齢医学研究所, 助教 (20578968) ; SAKAMOTO SHUICHI 東北大学, 電気通信研究所, 准教授 (60332524)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 脳磁図 / 視聴覚統合 / 時間窓 / 聴覚野

Outline of Final Research Achievements

Effects of visual speech on early auditory evoked fields were examined using a helmet-shaped magnetoencephalography. Significant visual-speech effects on P50m (shortening of latency and reduction of amplitude) were observed in both hemispheres, but those on N100m were observed only in the left hemisphere. The present results may indicate that the left hemispheric dominance of lip-reading effects, which is well known at the level of the superior temporal sulcus, begins to be apparent from around the N100m level, although the lip-reading effects could be observed at the P50m level. Moreover, visual speech effects on N100m observed in the left hemisphere were maintained as long as the temporal asynchrony between A/V stimuli was within 100 ms, but not with audio lag of -500 and +500 ms; i.e., the temporal window (a limited range in which A/V perceptual binding occurs) observed in the N100m in the left hemisphere was well-correlated with that in psychophysical measurements.

Free Research Field

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