The effect of sound intensity on the audiotactile crossmodal dynamic capture task
Valeria Occelli, Charles Spence, Massimiliano Zampini
Poster
Last modified: 2008-05-13
Abstract
We investigated the effect of the sound intensity on an audiotactile crossmodal dynamic capture task. Participants had to discriminate the direction of a target stream (tactile, Exp.1; auditory, Exp.2) while trying to ignore the direction of a distractor stream (auditory, Exp.1; tactile, Exp.2). The distractor streams could either be spatiotemporally congruent or incongruent with respect to the target stream. One group of participants was presented with 75dB auditory stimuli and another group with 82dB auditory stimuli. In Exp.1, the performance of the two groups was significantly affected by the intensity of the sounds, with high-intensity distractors inducing a stronger capture effect on tactile targets than the low-intensity distractors. In Exp.2, the interference induced by tactile distractors on the discrimination of the direction of the auditory target stream was comparable between the two groups. We also found that performance on both tasks was significantly modulated by the intensity of the auditory stimuli in a within-participants design. High-intensity distractors were more effective than low-intensity distractors in ‘capturing’ the perceived direction of tactile targets (Exp.3) and the interference induced by tactile distractors was greater on the low-intensity than on the high-intensity stimuli (Exp.4). The potential role of expectancy could account for the partially discordant results when comparing the between- and within-participants patterns of results.