The neural organization in parietal cortex serving communication related to representation and cognition of facial expression.

猴的顶叶皮质与运动和感觉信息(如视觉、听觉和躯体感觉)的整合有关，是已知的控制口腔和面部运动的区域。因此，对于口腔和面部运动，顶叶内皮质被认为是与不同个体之间的意义交流有关的信息处理的辅助。如果我们记录了脚内皮质中的神经元，这些神经元既对代表自己特定面部表情的神经元做出反应，也对观察他人特定面部表情做出反应，就有可能解释猴子的顶叶内皮质在与面部表情相关的意义交流中发挥着重要作用。在这项研究中，我们使用了行为和电生理技术来研究我们的意义传达理论。在行为实验中，通过图像分析仪测量了猴子的面部运动和眼动。首先，我们确定猴子面部的特征点(如嘴角和眼球)。其次，测量这些特征点的运动并进行数字化。在电生理实验中，我们记录了清醒猕猴顶叶皮质中的神经元。为了确定这些神经元的反应特性，根据它们的行为模式分析了这些神经元的活动。结果，我们记录了对执行自己的特定动作和观察他人类似动作的神经元做出反应的神经元。这些神经元在顶叶皮质的存在表明，顶叶皮质与动作意义的编码有关。据认为，与面部表情交流有关的类似神经元也存在于顶叶皮质中。

The intraparieatal cortex of monkeys is related to an integration of motor and sensory information (e.g.,vision, audition and somatosensory), and is known to an area controlling the oral and facial movements. Accordingly, for the oral and facial movement, it is supposed that the intraparietal cortex subserves an information processing related to communication of meaning between different individuals. If we record neurons in the intrapaeital cortex which respond to both representing a specific facial expression of one's own and observing a specific facial expression of others, it is possible to interpret that the monkey's intraparietal cortex subserbes an important role on communication of meaning related to facial expression. In this study, we executed behavioral and electrophysiological techniques to investigate our theory on communication of meaning.In behavioral experiments, monkey's facial movement and eye movement are measured by an image-analyzing apparatus in the following steps. First, we decided characteristic points on monkey's face (e.g., angle of mouth and eyeball). Second, motions of these characteristic points are measured and are digitized. As a result, monkey's facial expression was classified into three categories, that is, menacing face, frightened face and smacking face.In electrophysiological experiments, we recorded neurons in the intraparietal cortex of awake monkeys. To identify response properties of these neurons, these neuronal activities were analyzed according to their behavior patterns. As a result, we recorded neurons which responded to both executing a specific action of one's own and observing the similar action of others. The existence of these neurons in the intraparietal cortex indicates that the intraparietal cortex is related to coding of action meaning. It is considered that similar neurons related to communication of facial expression also exist in the intraparietal cortex.