认知与发展心理学研究室知识库

研究背景:生物运动识别对个体的生存和社会交互有重要意义。目前的研究己经发现，生物运动的特征识别效应包括形状效应、倒置效应和行进方向效应。而生物运动相关的脑成像研究、神经生物学研究、脑损伤研究和脑疾病研究都揭示了颗上沟在生物运动信息加工中非常重要。虽然，双通路模型为理解生物运动信息加工的过程提供了良好的理论基础，但缺乏神经电生理方面的实证研究证据。

研究目的:探究猕猴MST对生物运动三种特征信息(形状、倒置效应、行进方向)的编码。

实验设计:本实验采用2*2*2的三因素实验设计，三个因素分别是形状、倒置效应、行进方向。形状因素有2个水平，分别为形状完整和形状打乱(intact-scrambled。倒置效应因素有2个水平，分别为正立和倒立(upright-inverted。行进方向因素有2个水平，分别为向右走和向左走C right-left。总共有8种组合。

实验结果:对单个神经元的分析结果表明，猕猴MST脑区中存在可以同时编码生物运动三种特征信息的神经元，也存在编码两个或单一特征的神经元。对群体神经元的分析结果表明:(1>神经元对生物运动中光点小人的的形状完整与形状打乱的反应存在显著差异;(2>神经元对生物运动中光点小人的正立和倒立的反应存在显著差异;(3)神经元偏好行进方向的光点小人的反应与非偏好行进方向的光点小人的反应出现显著差异。

结论与讨论:猕猴MST脑区可以编码生物运动的形状特征、倒置效应特征和行进方向特征。从单个神经元对生物运动的反应来看，MST神经元对生物运动特征信息的编码可能过程是先编码单一特征信息，再通过单一特征组合完成双特征编码，通过层层递进和过滤机制最终完成对生物运动特征信息的编码。本研究为MST脑区参与编码生物运动形状特征、倒置效应特征、特别是行进方向特征提供了神经电生理方面的证据。

Background: Biological motion recognition is important for individual survival and social interaction. Current researches have found that recognition effects of biological motion include form, inversion effects, and walking direction. The researches on brain imaging, neurobiology, brain injury and brain diseases related to biological motion have revealed that the superior temporal sulcus is very important in biological motion information processing. Although the two-pathway model provides a good theoretical basis for understanding the process of biological motion information processing, it lacks empirical research eviendce on neuroeletrophysiology.

Purpose: The aim of our research is to explore how macaque meidal superior temporal area(MST) encodes the three features of biological motion(form, inversion effect and walking direction.

Experimental design: This experiment adopts 2*2*2 three-factor experimental design, and the three factors are form, inversion effect and walking direction. Form factor has two levels, form information intact and form information scrambled (intact vs scrambled). Inversion effect has two levels, upright and inverted. Walking direction has two levels, walking right and walking left.

Results: Single neuron analysis shows that there are neurons in macaque MST that can simultaneously encode three features of biological movement, and there are also neurons that can encode two or one single feature. The results of neuron population analysis showed that: (1) there was a significant difference in the neurons' response to the intact form point light display and scrambled point light display; (2) there was a significant difference in the neurons' response to the upright point light display and inverted point light display; (3) there was a significant difference in the neurons' response to preferential walking directional point light display and non-preferential walking directional point light display.

Conclusion and discussion: The MST brain region of macaques can encode three kinds of feature information of biological motion, namely form, inversion effect, and walking direction. From the response of single neurons to biological motion, it can be seen that the encoding process of MST neurons for biological motion feature information may be that they first encode single feature information, then complete double feature coding through single feature combination, and finally complete the encoding of biological motion feature information through successive layers and filtering mechanism. This study provided neuroelectrophysiological evidence for MST brain region to participate in encoding biological motion form feature, inversion effect feature, especially the walking direction feature.