Bayesian Calibration of Simultaneity in Audiovisual Temporal Order Judgments

PLoS One

Shigeru Kitazawa¹  Takayuki Iwano²  Shinya Yamamoto²  Makoto Miyazaki³ 

[1] Department of Neurophysiology, Juntendo University Graduate School of Medicine, Tokyo, Japan;Human Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan;Research Institute for Time Studies, Yamaguchi University, Yamaguchi, Japan

关键词: Neuronal tuning;    Neurons;    Acoustic signals;    Distribution curves;    Sensory perception;    Vision;    Visual signals;    Audio signal processing;   

DOI  :  10.1371/journal.pone.0040379

学科分类：医学（综合）

来源: Public Library of Science

【 摘 要 】

After repeated exposures to two successive audiovisual stimuli presented in one frequent order, participants eventually perceive a pair separated by some lag time in the same order as occurring simultaneously (lag adaptation). In contrast, we previously found that perceptual changes occurred in the opposite direction in response to tactile stimuli, conforming to Bayesian integration theory (Bayesian calibration). We further showed, in theory, that the effect of Bayesian calibration cannot be observed when the lag adaptation was fully operational. This led to the hypothesis that Bayesian calibration affects judgments regarding the order of audiovisual stimuli, but that this effect is concealed behind the lag adaptation mechanism. In the present study, we showed that lag adaptation is pitch-insensitive using two sounds at 1046 and 1480 Hz. This enabled us to cancel lag adaptation by associating one pitch with sound-first stimuli and the other with light-first stimuli. When we presented each type of stimulus (high- or low-tone) in a different block, the point of simultaneity shifted to “sound-first” for the pitch associated with sound-first stimuli, and to “light-first” for the pitch associated with light-first stimuli. These results are consistent with lag adaptation. In contrast, when we delivered each type of stimulus in a randomized order, the point of simultaneity shifted to “light-first” for the pitch associated with sound-first stimuli, and to “sound-first” for the pitch associated with light-first stimuli. The results clearly show that Bayesian calibration is pitch-specific and is at work behind pitch-insensitive lag adaptation during temporal order judgment of audiovisual stimuli.

【 授权许可】

CC BY