ERATO Asada project, Japan Science and Technology Agency, Sakyo-ku, Kyoto, Japan.
Neuroimage. 2011 May 15;56(2):728-35. doi: 10.1016/j.neuroimage.2010.10.043. Epub 2010 Oct 23.
We investigated the neural representation of observed actions in the human parietal and premotor cortex, which comprise the action observation network or the mirror neuron system for action recognition. Participants observed object-directed hand actions, in which action as well as other properties were independently manipulated: action (grasp or touch), object (cup or bottle), perspective (1st or 3rd person), hand (right or left), and image size (large or small). We then used multi-voxel pattern analysis to determine whether each feature could be correctly decoded from regional activities. The early visual area showed significant above-chance classification accuracy, particularly high in perspective, hand, and size, consistent with pixel-wise dissimilarity of stimuli. In contrast, the highest decoding accuracy for action was observed in the anterior intraparietal sulcus (aIPS) and the ventral premotor cortex (PMv). Moreover, the decoder for action could be correctly generalized for images with high dissimilarity in the parietal and premotor region, but not in the visual area. Our study indicates that the parietal and premotor regions encode observed actions independent of retinal variations, which may subserve our capacity for invariant action recognition of others.
我们研究了人类顶叶和运动前皮质中观察到的动作的神经表示，这些区域构成了动作观察网络或动作识别的镜像神经元系统。参与者观察了指向物体的手部动作，其中动作以及其他属性被独立操纵：动作（抓握或触摸）、物体（杯子或瓶子）、视角（第一人称或第三人称）、手（右手或左手）和图像大小（大或小）。然后，我们使用多体素模式分析来确定每个特征是否可以从区域活动中正确解码。早期视觉区域显示出显著高于随机的分类准确性，特别是在视角、手和大小方面，这与刺激的像素差异一致。相比之下，在前内顶叶回（aIPS）和腹侧运动前皮质（PMv）中观察到了最高的动作解码准确性。此外，动作解码器可以正确地推广到顶叶和运动前区域差异较大的图像，而不是在视觉区域。我们的研究表明，顶叶和运动前区域独立于视网膜变化来编码观察到的动作，这可能有助于我们对他人不变的动作识别能力。
