Biorthonormal expansion formulas for signal spaces composed of fluency functions and their applications

Thesis (Ph.D. in Engineering)--University of Tsukuba, (A), no. 1258, 1994.3.2

Effect of Visual Stimuli on Temporal Order Judgments of a Sequence of Pure Tones

We investigated what effect visual spatial information had on auditory temporal order judgments (TOJs) and examined what effect visual stimuli had on the TOJs of sequences of pure tones in experiment 1. The auditory stimuli were sequences of four distinct pure tones. The visual stimuli consisted of two vertically aligned flashes: one flashed before the first tone and the other flashed after the last tone. Participants judged whether the temporal order of the second and third tones in auditory stimuli occurred with the higher tone being first or the lower tone being first. As a result, the proportion of responses for higher-tone-first increased when the flash of the upper LED preceded that of the lower LED, independent of the actual temporal order. Participants in experiment 2 were asked to make simultaneity judgments instead, which were also affected by visual stimuli. The auditory stimuli in experiment 3 were the same as those in experiment 1, whereas the visual stimuli consisted of two horizontally aligned flashes. Furthermore, the participants made TOJs, which were not affected by the horizontally aligned visual stimuli. We concluded that vertically aligned visual stimuli had an effect on auditory TOJs with some response bias

Effect of Size Change and Brightness Change of Visual Stimuli on Loudness Perception and Pitch Perception of Auditory Stimuli

People obtain a lot of information from visual and auditory sensation on daily life. Regarding the effect of visual stimuli on perception of auditory stimuli, studies of phonological perception and sound localization have been made in great numbers. This study examined the effect of visual stimuli on perception in loudness and pitch of auditory stimuli. We used the image of figures whose size or brightness was changed as visual stimuli, and the sound of pure tone whose loudness or pitch was changed as auditory stimuli. Those visual and auditory stimuli were combined independently to make four types of audio-visual multisensory stimuli for psychophysical experiments. In the experiments, participants judged change in loudness or pitch of auditory stimuli, while they judged the direction of size change or the kind of a presented figure in visual stimuli. Therefore they cannot neglect visual stimuli while they judged auditory stimuli. As a result, perception in loudness and pitch were promoted significantly around their difference limen, when the image was getting bigger or brighter, compared with the case in which the image had no changes. This indicates that perception in loudness and pitch were affected by change in size and brightness of visual stimuli