Igarashi Yuka, Kitagawa Norimichi, Ichihara Shigeru
Department of Psychology, Tokyo Metropolitan University, 1-1, Minami-osawa, Hachioji, Tokyo 192-0397, Japan.
Cogn Affect Behav Neurosci. 2004 Jun;4(2):182-92. doi: 10.3758/cabn.4.2.182.
The participants in this study discriminated the position of tactile target stimuli presented at the tip or the base of the forefinger of one of the participants' hands, while ignoring visual distractor stimuli. The visual distractor stimuli were presented from two circles on a display aligned with the tactile targets in Experiment 1 or orthogonal to them in Experiment 2. Tactile discrimination performance was slower and less accurate when the visual distractor stimuli were presented from incongruent locations relative to the tactile target stimuli (e.g., tactile target at the base of the finger with top visual distractor) highlighting a cross-modal congruency effect. We examined whether the presence and orientation of a simple line drawing of a hand, which was superimposed on the visual distractor stimuli, would modulate the cross-modal congruency effects. When the tactile targets and the visual distractors were spatially aligned, the modulatory effects of the hand picture were small (Experiment 1). However, when they were spatially misaligned, the effects were much larger, and the direction of the cross-modal congruency effects changed in accordance with the orientation of the picture of the hand, as if the hand picture corresponded to the participants' own stimulated hand (Experiment 2). The results suggest that the two-dimensional picture of a hand can modulate processes maintaining our internal body representation. We also observed that the cross-modal congruency effects were influenced by the postures of the stimulated and the responding hands. These results reveal the complex nature of spatial interactions among vision, touch, and proprioception.
本研究中的参与者辨别呈现于其中一名参与者一只手食指指尖或基部的触觉目标刺激的位置，同时忽略视觉干扰刺激。在实验1中，视觉干扰刺激从显示屏上与触觉目标对齐的两个圆圈呈现；在实验2中，则与触觉目标正交呈现。当视觉干扰刺激相对于触觉目标刺激从不一致的位置呈现时（例如，手指基部的触觉目标与顶部视觉干扰物），触觉辨别表现更慢且准确性更低，这突出了一种跨模态一致性效应。我们研究了叠加在视觉干扰刺激上的一只手的简单线条图的存在和方向是否会调节跨模态一致性效应。当触觉目标和视觉干扰物在空间上对齐时，手部图片的调节作用较小（实验1）。然而，当它们在空间上未对齐时，效应要大得多，并且跨模态一致性效应的方向根据手部图片的方向而改变，就好像手部图片与参与者自己受刺激的手相对应一样（实验2）。结果表明，一只手的二维图片可以调节维持我们内部身体表征的过程。我们还观察到，跨模态一致性效应受受刺激手和反应手的姿势影响。这些结果揭示了视觉、触觉和本体感觉之间空间相互作用的复杂性。
