Section of Neuropsychology, Department of Cognitive Neurology, Hertie-Institute for Clinical Brain Research and Center for Integrative Neuroscience, University Clinic Tübingen, D-72076 Tübingen, Germany.
J Neurosci. 2011 Mar 2;31(9):3493-9. doi: 10.1523/JNEUROSCI.4277-10.2011.
The execution of motor behavior influences concurrent visual action observation and especially the perception of biological motion. The neural mechanisms underlying this interaction between perception and motor execution are not exactly known. In addition, the available experimental evidence is partially inconsistent because previous studies have reported facilitation as well as impairments of action perception by concurrent execution. Exploiting a novel virtual reality paradigm, we investigated the spatiotemporal tuning of the influence of motor execution on the perception of biological motion within a signal-detection task. Human observers were presented with point-light stimuli that were controlled by their own movements. Participants had to detect a point-light arm in a scrambled mask, either while executing waving movements or without concurrent motor execution (baseline). The temporal and spatial coherence between the observed and executed movements was parametrically varied. We found a systematic tuning of the facilitatory versus inhibitory influences of motor execution on biological motion detection with respect to the temporal and the spatial congruency between observed and executed movements. Specifically, we found a gradual transition between facilitatory and inhibitory interactions for decreasing temporal synchrony and spatial congruency. This result provides evidence for a spatiotemporally highly selective coupling between dynamic motor representations and neural structures involved in the visual processing of biological motion. In addition, our study offers a unifying explanation that reconciles contradicting results about modulatory effects of motor execution on biological motion perception in previous studies.
运动行为的执行会影响同时进行的视觉动作观察，尤其是对生物运动的感知。这种感知和运动执行之间相互作用的神经机制尚不清楚。此外，现有的实验证据部分不一致，因为先前的研究报告称，同时进行的动作执行既可以促进也可以损害动作感知。我们利用一种新颖的虚拟现实范式，在信号检测任务中研究了运动执行对生物运动感知的时空调节。研究人员向被试呈现由自身运动控制的光点刺激。参与者必须在混乱的掩蔽中检测到一个光点手臂，要么在执行挥手运动时，要么在没有同时进行运动执行（基线）时。观察到的和执行的运动之间的时间和空间连贯性是参数化变化的。我们发现，运动执行对生物运动检测的促进与抑制影响与观察到的和执行的运动之间的时间和空间一致性之间存在系统的调节。具体来说，我们发现随着时间同步性和空间一致性的降低，促进和抑制相互作用之间逐渐过渡。该结果为动态运动表示与参与生物运动视觉处理的神经结构之间的时空高度选择性耦合提供了证据。此外，我们的研究提供了一个统一的解释，调和了先前研究中关于运动执行对生物运动感知的调节作用的矛盾结果。
