Ishigami Yoko, Phillips Dennis P
Department of Psychology, Dalhousie University, 1355 Oxford Street, Halifax, NS, Canada B3H 4J1.
Hear Res. 2008 Jul;241(1-2):97-102. doi: 10.1016/j.heares.2008.05.003. Epub 2008 May 13.
Auditory saltation is the orderly misperception of the spatial location of repetitive click stimuli emitted from two successive locations when the inter-click intervals (ICIs) are sufficiently short. The clicks are perceived as originating not only from the actual source locations, but also from locations between them. In two tasks, the present experiment compared free-field auditory saltation for 90 degrees excursions centered in the frontal, rear, left and right acoustic hemifields, by measuring the ICI at which subjects report 50% illusion strength (subjective task) and the ICI at which subjects could not distinguish real motion from saltation (objective task). A comparison of the saltation illusion for excursions spanning the midline (i.e. for frontal or rear hemifields) with that for stimuli in the lateral hemifields (left or right) revealed that the illusion was weaker for the midline-straddling conditions (i.e. the illusion was restricted to shorter ICIs). This may reflect the contribution of two perceptual channels to the task in the midline conditions (as opposed to one in the lateral hemifield conditions), or the fact that the temporal dynamics of localization differ between the midline and lateral hemifield conditions. A subsidiary comparison of saltation supported in the left and right auditory hemifields, and therefore by the right and left auditory forebrains, revealed no difference.
听觉跳跃是指当相继两次发出的重复点击刺激的点击间隔（ICI）足够短时，对其空间位置产生的有序错误感知。这些点击不仅被感知为来自实际的声源位置，还被感知为来自它们之间的位置。在两项任务中，本实验通过测量受试者报告50%错觉强度时的ICI（主观任务）以及受试者无法区分真实运动和跳跃时的ICI（客观任务），比较了以额、后、左、右听觉半场为中心的90度偏移的自由场听觉跳跃。对跨越中线的偏移（即额或后半场）的跳跃错觉与外侧半场（左或右）刺激的跳跃错觉进行比较发现，中线跨越条件下的错觉较弱（即错觉仅限于较短的ICI）。这可能反映了在中线条件下两种感知通道对任务的贡献（与外侧半场条件下的一种通道相对），或者中线和外侧半场条件下定位的时间动态存在差异。对左、右听觉半场以及因此由左、右听觉前脑支持的跳跃进行的辅助比较没有发现差异。
