生物运动特征信息的神经编码机制
文献类型：学位论文
| 作者 | 丰婷婷 |
| 答辩日期 | 2022-12 |
| 文献子类 | 博士 |
| 授予单位 | 中国科学院大学 |
| 授予地点 | 中国科学院心理研究所 |
| 其他责任者 | 张弢 |
| 关键词 | 生物运动 内侧颞区 中上颞区 形状提取 空间转换 |
| 学位名称 | 理学博士 |
| 学位专业 | 认知神经科学 |
| 其他题名 | The information coding mechanism of biological motion |
| 中文摘要 | Biological motion perception is essential for individuals’ survival, development and social interaction, which is innately inherited and evolutionary conserved cross many species. The ability to recognize biological movement is so stable that the observers are able to perceive the movement of a dozen point-light attached to the joints of an actor as a moving person, and can identify gender, identity, emotion, etc. from them. Despite the substantial behavior, brain imaging and brain damaging studies regarding this topic, the neural mechanism of biological motion perception still remains unclear due to lacking of electrophysiological evidence. To investigate the neural coding mechanism of biological motion information, we used point-light biological motion, depicted by motion cues alone, to study how biological motion information is processed on the basis of kinematics alone. A plenty of electrophysiological studies have shown that MT (medial temporal area) and MST (middle superior temporal area) are two important motion sensitive brain area in the dorsal visual pathway. Therefore, we chose MT and MST in macaque to explore the neural mechanism of encoding biological motion information. In this study, the electrophysiological recording technology for awake monkeys was used to record the electrical activity of neurons while the monkeys were passively viewing different kinds of visual stimuli. The visual stimuli used in current experiment included both biological motion and optic flow. The biological motion visual stimuli were classified into form intact and form scrambled according to form information; up and down according to inversion information; right and left according to walking direction. The optical flow stimuli included linear (8 directions with 45°apart ) and non-linear (expansion, contraction, clockwise, and counter-clockwise). We found that MST neurons are capable of extracting form information from motion kinematic signals, and encoding inversion and discriminating walking directions. More importantly, our results revealed that biological motion information is dynamically encoded in the temporal structure of evoked spikes trains, instead of average firing rate during stimulus presentation. MT neurons cannot extract form information from biological motion, but can discriminate inversion and walking directions. Although MT and MST neurons can encode inversion, MST neurons’ modulation induced by upright biological motion was significantly higher than inverted condition, but this is not the case for MT neurons. Furthermore, the capability of MST neurons in detecting various biological motion features is closely related to the neuronal selectivity to optic flow pattern. These results suggest that macaque MST neurons is capable of encoding biological motion information in a dynamical mode, and this capability to encode biological motion features may stem from the selectivity of MST neurons for optical flow pattern. These results indicate that MST is a key brain area for biological motion recognition, and to a large extent reveal the neural coding mechanism for processing biological motion information in the dorsal visual pathway. |
| 英文摘要 | 识别生物运动对于个体的生存、发展以及社会交互是至关重要的，这种知觉生物运动的能力具有先天遗传以及跨物种的特性，并且非常稳定，以至于仅仅依赖于人体主要关节点的运动，观察者就能够将一系列点的运动知觉为运动的人，并且能够从中识别出性别、身份、情绪等信息。尽管有大量关于生物运动识别的行为学、脑成像研究以及脑损伤的研究，但是由于缺乏神经电生理的证据，生物运动信息加工的神经机制依然未知。为了探究生物运动特征信息的神经编码机制，本研究使用 PLD(point-light-display)类型生物运动刺激。因为 PLD 生物运动仅包含生物运动中的运动信息，所以可以更好地研究神经系统如何依靠运动信息来加工生物运动特征信息。大量的研究表明，MT(medial temporal area)和 MST(middle superior temporal area)是背侧通路加工运动信息的两个重要脑区，因此，我们选择猕猴的 MT 和 MST 作为目标脑区来探究生物运动信息编码的神经机制。 本研究采用清醒猴神经电生理记录技术，在猴子观看视觉刺激的同时，记录神经元的电活动。本实验中使用的视觉刺激包括生物运动视觉刺激和光流刺激，其中生物运动视觉刺激根据形状特征信息可分为形状完整和形状打乱；根据正倒立特征信息可分为正立和倒立；根据行进方向可分为向左走和向右走。光流刺激包括：八种不同方向的二维平动光流和四种光流模式(正旋、逆旋、扩张、收缩)。 结果发现，MST 可以从生物运动中提取出形状信息，能够编码正倒立特征信息和进行方向特征信息，并且对生物运动特征信息的编码是通过刺激呈现期间神经元动作电位发放频率的动态变化来实现的，而不是平均发放频率；而 MT 则不能够编码生物运动中的形状特征信息，但是可以编码正倒立以及行进方向特征信息。虽然 MT 和 MST 神经元都可以编码正倒立特征信息，但是正立生物运动对 MST 神经元的调制好于倒立神经元，但是 MT 脑区则没有这一现象。进一步分析发现，MST 神经元对生物运动特征信息的编码与神经元对光流模式的选择性之间存在相关。这些结果表明，MST 可以通过动态编码的方式加工生物运动信息，并且这种对生物运动特征信息的编码能力可能来源于 MST 神经元对光流模式的选择性。这些结果表明 MST 是生物运动加工的关键脑区，很大程度上揭示生物运动信息在背侧视觉通路进行加工的神经编码机制。 |
| 语种 | 中文 |
| 源URL | [http://ir.psych.ac.cn/handle/311026/44374]  |
| 专题 | 心理研究所_认知与发展心理学研究室 |
| 推荐引用方式 GB/T 7714 | 丰婷婷. 生物运动特征信息的神经编码机制[D]. 中国科学院心理研究所. 中国科学院大学. 2022. |
入库方式： OAI收割
来源：心理研究所
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