Gallace Alberto, Auvray Malika, Spence Charles
Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OX1 3UD, UK.
Perception. 2007;36(7):1003-18. doi: 10.1068/p5457.
Research has shown that a variety of different sensory manipulations, including visual illusions, transcutaneous nerve stimulation, vestibular caloric stimulation, optokinetic stimulation, and prism adaptation, can all influence people's performance on spatial tasks such as line bisection. It has been suggested that these manipulations may act upon the 'higher-order' levels of representation used to code spatial information. We investigated whether we could influence haptic line bisection in normal participants crossmodally by varying the visual background that participants viewed. In experiment 1, participants haptically bisected wooden rods while looking at a variant of the Oppel - Kundt visual illusion. Haptic-bisection judgments were influenced by the orientation of the visual illusion (in line with previous unimodal visual findings). In experiment 2, haptic-bisection judgments were also influenced by the presence of a leftward or rightward moving visual background. In experiments 3 and 4, the position of the to-be-bisected stimuli was varied with respect to the participant's body midline. The results confirmed an effect of optokinetic stimulation, but not of the Oppel -Kundt illusion, on participants' tactile-bisection errors, suggesting that the two manipulations might differentially affect haptic processing. Taken together, these results suggest that the 'higher-order' levels of spatial representation upon which perceptual judgments and/or motor responses are made may have multisensory or amodal characteristics.
研究表明，包括视觉错觉、经皮神经刺激、前庭冷热刺激、视动刺激和棱镜适应在内的各种不同的感觉操纵，都能影响人们在诸如直线二等分等空间任务中的表现。有人提出，这些操纵可能作用于用于编码空间信息的“高阶”表征水平。我们研究了是否可以通过改变参与者所看到的视觉背景，以跨模态方式影响正常参与者的触觉直线二等分。在实验1中，参与者在观看奥佩尔-昆特视觉错觉的变体时，对木杆进行触觉二等分。触觉二等分判断受到视觉错觉方向的影响（与之前的单模态视觉研究结果一致）。在实验2中，触觉二等分判断也受到向左或向右移动的视觉背景的影响。在实验3和4中，待二等分刺激的位置相对于参与者的身体中线发生变化。结果证实了视动刺激对参与者触觉二等分误差有影响，但奥佩尔-昆特错觉没有影响，这表明这两种操纵可能对触觉加工有不同的影响。综合来看，这些结果表明，做出感知判断和/或运动反应所依据的空间表征的“高阶”水平可能具有多感官或非模态特征。
