【作者】 赵坤；

【导师】 万红；

【作者基本信息】 郑州大学 ， 控制科学与工程， 2021， 博士

【摘要】 快速准确的目标导向行为(例如迁徙、归巢、觅食等)与动物的生存息息相关,在此过程中动物大脑对环境的高效适应性是动物智能的重要体现。目标导向行为中的多种认知过程都是服务于目标的识别与选择的。现有的研究结果表明目标信息的稳定表征需要多个脑区的参与,因此脑区间的信息传递对于目标信息表征的实现至关重要。鸽子目标导向行为中,作为信息汇集脑区的弓状皮质尾外侧区(nidopallium caudolaterale,NCL)与海马区(hippocampus,Hp)扮演了重要角色。但是这两个脑区是如何对目标信息进行表征,同时目标信息在两脑区所构成的局部网络中又是如何进行信息传递的,目前均尚不清楚。研究目标导向行为中鸽脑NCL区与Hp区对目标信息的表征与传递机制,对于探索鸽子大脑在目标导向行为中的信息处理机制具有重要价值,同时该研究对于类脑智能和仿生导航等领域也具有积极意义。为揭示目标信息在大脑中的的表征与传递机制,本文以鸽子作为模式动物,设计并开展了具有目标信息差异的两种目标导向任务,采用微电极阵列在体记录技术,实时采集任务执行过程中鸽子NCL区与Hp区的局部场电位信号(Local field potentials,LFP),通过耦合分析、复杂网络分析、信息传递模式分析及行为解码,解析了NCL区与Hp区在目标信息表征中的协同作用,并量化分析了目标导向行为中NCL区与Hp区对目标信息的传递模式;在此基础上,实现了对鸽子目标导向行为转向行为的有效预测。本文具体研究成果如下:(1)解析了鸽子目标导向行为中NCL区对目标信息的编码特征,实现了对目标信息解码和鸽子转向行为的有效预测。依据目标导向任务中目标信息的差异,设计了非预设目标导向、预设目标导向两种行为任务,利用时频分析确定了鸽子NCL区LFP信号40-60 Hz频带能量的选择性增强与目标所处位置相关;同时,预设目标任务中NCL区响应的时间特性显著早于非预设目标任务,基于这一发现在鸽子转向行为前,实现了对鸽子转向行为的有效预测。(2)为解析目标导向行为中Hp区多响应特征下其目标信息表征相关的响应特性,利用幅度—幅度耦合分析,由Hp区LFP信号复杂的任务响应特性中,确定了Hp区参与目标信息表征的频带与时间窗。耦合分析结果表明,Hp区LFP信号低频gamma频带与NCL区目标信息表征频带的耦合值显著高于其他频带,并且该耦合关系的时间窗受目标信息的调制。(3)发现Hp区基于与NCL区功能联系的连接模式与时间窗共同参与了对目标信息的表征。基于Hp-NCL功能网络分析发现Hp区与NCL区之间存在呈现高度聚集特点的功能联系,Hp-NCL功能网络的连接模式对于目标所处不同空间位置存在显著差异,同时两脑区功能联系所处的时间窗会因目标被获知时刻的调制而改变。(4)基于Hp-NCL信息传递的量化分析,明确了NCL区与Hp区间的信息传递模式。通过分析Hp区与NCL区信息传递量的动态变化,确定了在目标导向行为过程中鸽子Hp区与NCL区信息传递集中的时间窗;基于两脑区因果关系分析,揭示了两脑区信息传递的主要方向是由Hp区到NCL区;同时,同步性分析结果表明两脑区以低频gamma频带振荡实现了脑区间的信息传递。更多还原

【Abstract】 Goal-directed behavior,such as migration,homing,and foraging,is essential for the survival of animals.In this process,animal brain efficient adapting to the environment is an important embodiment of intelligence.During goal-directed behavior,cognitive processing is orchestrated to serve the identification and selection of goals.The existing research indicates the stable representation of goal information needs the accurate coordination of multiple brain regions.Thus,the information transfer among brain regions is very important for the execution of tasks.However,how the goal information is represented in the NCL and Hp regions which as the center of various information integration in pigeon,and how the goal information is transmitted in the network of the two brain regions is unclear.Research on the representation and transmission mechanism of goal information in goal-directed behavior is valuable for exploring the information processing mechanisms of the pigeon brain,and it is also of positive significance in brain-inspired intelligence and bionic navigation.To reveal the representation and transmission mechanism of goal information in the NCL and Hp regions,the pigeons are used as a model animal in this study.According to the difference of goal information in goal-oriented tasks,we design two behavioral tasks: without preset goal-directed task and preset goal-directed task.We record the neural signals in vivo from the NCL and Hp regions during the tasks by using the microelectrode array chronic implantation technology.Firstly,by comparing the time characteristics and frequency band characteristic of the LFP signals in NCL regions response during different behavioral tasks,we analyze the representation of the goal information in the NCL regions.Secondly,using coupling analysis and complex network method,the functional connectivity between the NCL and the Hp in the behavioral tasks and the modulation of the goal information on the Hp-NCL functional network are explored to reveal the common role of the NCL and the Hp in the representation of the goal information.Lastly,a method framework for quantitative analysis of Hp-NCL information transfer is proposed,and we analyze the transfer of goal information between Hp and NCL regions in goal-directed behavior.On this basis,the influence of Hp-NCL information transfer on pigeon goal-directed behavior is verified,and then we make an effective prediction for the turning behavior of pigeon during the goal-directed task.The main contents and innovation points of this thesis are presented as follows:(1)The characteristics of LFP signals encoding goal information in the NCL region are analyzed.According to the analysis results of the two goal-directed tasks with different goal information,we find that the 40-60 Hz of LFP recorded from the NCL region is the characteristic band which encode the goal information.Moreover,the power enhanced time window of the characteristic band moves forward with the advance of the time of the goal known.(2)Because of the energy characteristic of LFP signals recorded from the Hp region is complex during the goal-directed behavior.By the amplitude-amplitude coupling analysis,the frequency band and time window of the LFP related to goal information representation are determined.The results of the coupling analysis show that the coupling value between the slow gamma band in the Hp region and the goal information representation band in the NCL region is obviously higher than that of other frequency bands.Meanwhile,the time window of the coupling relationship is modulated by the goal information.These results solve the problem that the response characteristics of LFP recorded from the Hp region are difficult to determine.(3)Based on Hp-NCL functional network analysis,it is found that there is a highly clustered functional relation between the Hp region and the NCL region.On the basis of this connection mode and the time window,the Hp region participates in the representation of goal information by the NCL region.The Hp-NCL functional network connection mode in different goal location tasks exhibit significant difference.Meanwhile,the time window of the Hp-NCL functional relation will be modulated by the time of goal known.(4)A method framework of quantitative analysis of Hp-NCL information transfer is established to realize the multi-angle analysis of information transfer between brain regions.By analyzing the dynamic changes of information transfer between the Hp and NCL regions,the time window of information transfer between the Hp and the NCL regions is determined during the tasks.And we find that the main direction of information transfer in the two brain regions is from the Hp to the NCL by using functional causality analysis.Moreover,the information transfer in the two regions is achieved by the slow gamma-band oscillation during goal-directed behavior.On this basis,the effective prediction of pigeon turning behavior is realized.更多还原