California Polytechnic State University, San Luis Obispo, CA,USA.
Multisens Res. 2020 Mar 17;33(4-5):521-548. doi: 10.1163/22134808-20191387.
We often rely on our sense of vision for understanding the spatial location of objects around us. If vision cannot be used, one must rely on other senses, such as hearing and touch, in order to build spatial representations. Previous work has found evidence of a leftward spatial bias in visual and tactile tasks. In this study, we sought evidence of this leftward bias in a non-visual haptic object location memory task and assessed the influence of a task-irrelevant sound. In Experiment 1, blindfolded right-handed sighted participants used their non-dominant hand to haptically locate an object on the table, then used their dominant hand to place the object back in its original location. During placement, participants either heard nothing (no-sound condition) or a task-irrelevant repeating tone to the left, right, or front of the room. The results showed that participants exhibited a leftward placement bias on no-sound trials. On sound trials, this leftward bias was corrected; placements were faster and more accurate (regardless of the direction of the sound). One explanation for the leftward bias could be that participants were overcompensating their reach with the right hand during placement. Experiment 2 tested this explanation by switching the hands used for exploration and placement, but found similar results as Experiment 1. A third Experiment found evidence supporting the explanation that sound corrects the leftward bias by heightening attention. Together, these findings show that sound, even if task-irrelevant and semantically unrelated, can correct one's tendency to place objects too far to the left.
我们通常依赖视觉来理解周围物体的空间位置。如果无法使用视觉，人们必须依靠听觉和触觉等其他感觉来构建空间表象。先前的研究已经发现了在视觉和触觉任务中存在左向空间偏向的证据。在这项研究中，我们试图在非视觉触觉物体位置记忆任务中寻找这种左向偏向的证据，并评估了无关声音的影响。在实验 1 中，蒙住眼睛的右利手的视力正常参与者使用非主导手触觉定位桌子上的物体，然后用主导手将物体放回原来的位置。在放置过程中，参与者要么什么也听不到（无声条件），要么听到来自房间左侧、右侧或前方的无关重复音调。结果表明，参与者在无声试验中表现出左向放置偏向。在有声音的试验中，这种左向偏向得到了纠正；无论声音的方向如何，放置都更快、更准确。对左向偏向的一种解释可能是，参与者在放置时用右手过度补偿了他们的伸展。实验 2 通过切换用于探索和放置的手来检验这一解释，但发现与实验 1 类似的结果。第三个实验提供了证据支持声音通过提高注意力来纠正左向偏向的解释。总之，这些发现表明，即使声音是无关的和语义上不相关的，也可以纠正人们将物体放置得太靠左的倾向。
