Asymmetrical audiovisual perception in temporal order judgment

摘要

視覚情報と聴覚情報を使った時間情報処理を明らかにするために、時間同時性判断を視覚と聴覚信号の同期と非同期信号をつかって調べた。被験者は聴覚Pip信号とガボール視覚信号を提示され（1）視覚信号と聴覚信号それぞれの開始時間が同期した場合、（2）聴覚信号が50ms先行提示された場合、（3）視覚信号が50ms先行提示された場合の3つの条件において視覚と聴覚でどちらが最初に知覚されたかを答えた。その結果、視聴覚信号が同期した場合、被験者は96％の割合で同期したと答えた。聴覚信号が先行提示された場合、92％の割合で先行刺激が聴覚と答えた。しかし、視覚刺激が先行提示された場合、被験者は60％の割合で視覚と聴覚の刺激が同期して提示されたと答えた。このような、時間知覚に対する視覚と聴覚の非対称性は、聴覚の時間に対する反応特性の視覚に対する鋭敏性とともに、視覚と聴覚の処理時間が、皮質における時間知覚過程に影響を与えていることを示唆する。%To elucidate time perception using auditory and visual information, a temporal order judgment task was employed using a pip auditory signal and a Gabor visual signal. Timing was manipulated by changing onset asynchrony of the auditory and visual signals. Participants were asked which of visual or auditory signals were perceived to come earlier or simultaneous (1) when the visual and auditory signals were presented simultaneously, (2) when the auditory signal was presented prior to the visual signal, and (3) when the visual signal was presented prior to the auditory signal. The participants reported simultaneity by 96% when the visual and auditory signals were presented on time. They reported that auditory signal came faster by 92% when the auditory signal onset came earlier. However, they reported simultaneity by 75% when the visual signal onset came earlier up to 200ms onset asynchrony. This discrepancy of simultaneity between visual and auditory signal onset may be due to different processing time of the brain for visual and auditory signals that affects the process of cross-modal events.