Carter Olivia, Konkle Talia, Wang Qi, Hayward Vincent, Moore Christopher
Vision Sciences Laboratory, Harvard University, Cambridge, Massachusetts 02138, USA.
Curr Biol. 2008 Jul 22;18(14):1050-4. doi: 10.1016/j.cub.2008.06.027.
When observers view ambiguous visual stimuli, their perception will often alternate between the possible interpretations, a phenomenon termed perceptual rivalry [1]. To induce perceptual rivalry in the tactile domain, we developed a new tactile illusion, based on the visual apparent-motion quartet [2]. Pairs of 200 ms vibrotactile stimuli were applied to the finger pad at intervals separated by 300 ms. The location of each successive stimulus pair alternated between the opposing diagonal corners of the approximately 1 cm(2) stimulation array. This stimulation sequence led all participants to report switches between the perception of motion traveling either up and down or left and right across their fingertip. Adaptation to tactile stimulation biased toward one direction caused subsequent ambiguous stimulation to be experienced in the opposing direction. In contrast, when consecutive trials of ambiguous stimulation were presented, motion was generally perceived in the direction consistent with the motion reported in the previous trial. Voluntary eye movements induced shifts in the tactile perception toward a motion axis aligned along a world-centered coordinate frame. Because the tactile quartet results in switching perceptual states despite unvaried sensory input, it is ideally suited to future studies of the neural processes associated with conscious tactile perception.
当观察者观看模糊的视觉刺激时，他们的感知往往会在可能的解释之间交替，这种现象被称为感知竞争[1]。为了在触觉领域诱发感知竞争，我们基于视觉表观运动四重奏[2]开发了一种新的触觉错觉。以300毫秒的间隔向指腹施加200毫秒的振动触觉刺激对。每个连续刺激对的位置在大约1平方厘米的刺激阵列的对角相对角之间交替。这种刺激序列使所有参与者报告在他们指尖上上下下或左右移动的运动感知之间的切换。向一个方向的触觉刺激适应会导致随后的模糊刺激在相反方向被体验到。相比之下，当呈现连续的模糊刺激试验时，运动通常被感知为与前一次试验中报告的运动一致的方向。自愿的眼球运动会导致触觉感知朝着沿着以世界为中心的坐标系对齐的运动轴移动。由于触觉四重奏尽管感觉输入不变却导致感知状态的切换，它非常适合未来与有意识触觉感知相关的神经过程的研究。
