Crossmodal Research Laboratory, Department of Experimental Psychology, Oxford University, South Parks Road, Oxford OX1 3UD, UK.
Exp Brain Res. 2011 Aug;213(1):87-97. doi: 10.1007/s00221-011-2780-2. Epub 2011 Jun 30.
Goal-directed movements are characterized by sensory suppression, that is, by decreased sensitivity to tactile stimuli. In the present study, we investigated tactile suppression during movement using a complex motor task: basic 3-ball juggling. It was hypothesized that a decrease in tactile sensitivity would be observed, together with a shift in participants' response bias while juggling. In a first experiment, participants had to detect a short gap in an otherwise continuous vibratory stimulus, which was delivered to their wrist under conditions of rest or else while juggling. In a second experiment, participants detected a short time gap in a continuous auditory signal, under the same conditions. In a final control experiment performed at rest, participants detected a short time gap in an auditory or tactile signal. In an additional condition, the detection of a gap in tactile stimulation was required under conditions of intramodal tactile interference. Participants were significantly less sensitive to detect a gap in tactile stimulation whilst juggling. Most importantly, these results were paired with a significant shift toward participants adopting a more conservative criterion when responding to the presence of the gap (i.e. they were more likely to say that a gap was not present). Taken together, these results demonstrate movement-related tactile sensory suppression and point to a decisional component in tactile suppression, thus suggesting that tactile suppression could already be triggered in the brain ahead of the motor command.
目标导向运动的特点是感觉抑制，也就是说，对触觉刺激的敏感性降低。在本研究中，我们使用一项复杂的运动任务：基本的 3 球杂耍，来研究运动过程中的触觉抑制。我们假设，在杂耍时，触觉敏感度会降低，同时参与者的反应偏向也会发生变化。在第一个实验中，参与者必须在休息或杂耍时检测到振动刺激中的短暂间隙。在第二个实验中，参与者在相同条件下检测连续听觉信号中的短暂时间间隙。在最后一个在休息时进行的对照实验中，参与者在听觉或触觉信号中检测到短暂的时间间隙。在另一个条件下，需要在触觉干扰条件下检测触觉刺激中的间隙。参与者在杂耍时对检测触觉刺激中的间隙明显不敏感。最重要的是，这些结果与参与者在响应间隙存在时采用更保守的标准的显著变化相关（即他们更有可能说间隙不存在）。综上所述，这些结果表明运动相关的触觉感觉抑制，并指向触觉抑制中的决策成分，因此表明触觉抑制可能已经在运动指令之前在大脑中被触发。
