Auditory capture on the visual Ternus effect: the influence of subjective inter-sound interval
Zhuanghua Shi, Lihan Chen, Hermann J. Müller
Poster
Time: 2009-06-29 11:00 AM – 12:30 PM
Last modified: 2009-06-04
Abstract
Research on multi-sensory interactions has shown that the perceived timing of a visual event can be captured by a temporally proximal sound. This effect has been termed ‘temporal ventriloquism effect (TVE)’. It has been found that the TVE can be influenced by both auditory grouping and audio-visual temporal structure. In the present study, using the Ternus display we demonstrated that the subjective inter-sound-interval is another important factor contributes to the TVE, which is reflected on the changes of the transition threshold between two different percepts of apparent motion: ‘element motion’ and ‘group motion’.
In Experiment 1, the influences of dual-sound and multiple sounds on the visual apparent-motion were compared. The inter-sound-interval was fixed at 120 ms and each tone duration was 20 ms in both dual-sound and multiple-sound conditions. The transition threshold of two motion percepts was significant lower in dual-sound condition (117 ms) compared to that in multiple-sound condition (135 ms). The lower threshold means ‘group motion’ impression is dominant of the two alternative percepts, which indicates the ISI between two visual frames has been “dragged� longer. A further experiment on subjective inter-sound interval suggested that the inter-sound interval in the dual-sound was perceived 17 ms longer than that in multiple-sound with the physical equal interval(s) of 120ms. In Experiment 2, the transition thresholds of pure visual Ternus display and visual Ternus display with synchronous dual-sound, as well as the subjective inter-stimulus interval with and without sounds were compared. The results showed that the threshold between two apparent motion percepts was shifted lower in the condition with synchronous sounds by 25 ms. Furthermore, the results from subjective interval comparison suggested that subjective interval was longer with synchronous sounds than without sound.
In summary, the present study investigated the auditory-capture effect with the visual Ternus display using different auditory configurations. The same inter-stimulus interval leads to different capture effect. The main mechanism behinds this can be the subjective interval which itself is influenced by the auditory configuration.
In Experiment 1, the influences of dual-sound and multiple sounds on the visual apparent-motion were compared. The inter-sound-interval was fixed at 120 ms and each tone duration was 20 ms in both dual-sound and multiple-sound conditions. The transition threshold of two motion percepts was significant lower in dual-sound condition (117 ms) compared to that in multiple-sound condition (135 ms). The lower threshold means ‘group motion’ impression is dominant of the two alternative percepts, which indicates the ISI between two visual frames has been “dragged� longer. A further experiment on subjective inter-sound interval suggested that the inter-sound interval in the dual-sound was perceived 17 ms longer than that in multiple-sound with the physical equal interval(s) of 120ms. In Experiment 2, the transition thresholds of pure visual Ternus display and visual Ternus display with synchronous dual-sound, as well as the subjective inter-stimulus interval with and without sounds were compared. The results showed that the threshold between two apparent motion percepts was shifted lower in the condition with synchronous sounds by 25 ms. Furthermore, the results from subjective interval comparison suggested that subjective interval was longer with synchronous sounds than without sound.
In summary, the present study investigated the auditory-capture effect with the visual Ternus display using different auditory configurations. The same inter-stimulus interval leads to different capture effect. The main mechanism behinds this can be the subjective interval which itself is influenced by the auditory configuration.