Relevance of neuronal pre-stimulus oscillatory activity for the formation of crossmodal episodic memory

神经元刺激前振荡活动与跨模式情景记忆形成的相关性

• 批准号: 434050222
• 负责人: Professor Dr. Michael Rose
• 金额: --
• 依托单位: Institut für Systemische Neurowissenschaften
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/434050222?language=en
• 关键词: Relevance; neuronal; pre; stimulus; oscillatory

For several cognitive processes it was demonstrated that the neuronal activity prior to stimulus presentation modulates the consecutive processing of that stimulus. For memory formation our group and several other researchers demonstrated a pronounced influence of pre-stimulus oscillatory activity on memory encoding. This effect was mainly demonstrated for item memory presented in one modality. However, a key feature of episodic memory in the real world is the integration of different sensory modalities. Therefore, the aim of the present proposal is the examination of the functional role of pre-stimulus oscillatory activity for the formation of crossmodal associations. Based on theoretical assumptions and previous observations we hypothesize a functional relevance of oscillatory activity in the theta-band (4-8 Hz). The pre-stimulus theta band characteristics including amplitude and phase locking are hypothesized to be predictive for memory encoding for associations of information from different sensory modalities. Furthermore, the interactive effect of pre- and poststimulus activity for memory formation will be examined. The already developed and tested experimental design allows for assessing pure associative memory between visual and auditory stimuli independent from the memory for the individual stimuli. In the first section of the proposal audio-visual memory formation will be examined using EEG- measurements. Here, the relevance of pre-stimulus theta band amplitude and phase coupling and the relation of both parameters to post-stimulus processing will be examined. Theoretical models assumes that the coincident input from different sensory modalities to the hippocampus is realized by theta- band oscillatory activity. In the second section this assumption will be tested using combined EEG- and fMRI measurements. Here, the hypothesis is tested that theta-band pre-stimulus activity affects the consecutive processing within the hippocampus.The examination of the neuronal correlates of cross-sensory episodic memory should reflect the rich environment in which these memories are generated usually. Therefore, in the third section it is planned to test the reliability and validity of the laboratory results in a more realistic virtual reality (VR) setting. In the real world episodic memory is encoded in a natural context with is usually part of the memory. The VR setting is perfectly suited to test the encoding of more naturalistic contextual memory and the development of crossmodal association within that context. Furthermore, the behavior of the participants can be recorded in VR in detail to relate behavioral aspects to the formation of memory. Here, it is planned to test the influence of self-engaged actions and exploratory behavior (head- and eye-movements) on the pre-stimulus oscillatory state and memory encoding. Therefore, EEG will be measured simultaneously with the VR- stimulation in the last experiments.

对于一些认知过程，已证明刺激呈现之前的神经元活动调节该刺激的连续处理。对于记忆形成，我们的小组和其他几位研究人员证明了刺激前振荡活动对记忆编码的显着影响。这种效果主要针对以一种模式呈现的项目记忆得到证明。然而，现实世界中情景记忆的一个关键特征是不同感觉方式的整合。因此，本提案的目的是检查刺激前振荡活动对于形成跨模态关联的功能作用。基于理论假设和之前的观察，我们假设 θ 频段（4-8 Hz）振荡活动的功能相关性。假设包括幅度和锁相在内的刺激前 θ 带特征可以预测来自不同感觉模态的信息关联的记忆编码。此外，还将检查刺激前和刺激后活动对记忆形成的交互作用。已经开发和测试的实验设计允许评估视觉和听觉刺激之间的纯联想记忆，独立于个体刺激的记忆。 在提案的第一部分中，将使用脑电图测量来检查视听记忆的形成。在这里，将检查刺激前 theta 带幅度和相位耦合的相关性以及这两个参数与刺激后处理的关系。理论模型假设不同感觉模式到海马体的一致输入是通过 θ 带振荡活动实现的。在第二部分中，将使用脑电图和功能磁共振成像联合测量来测试这一假设。在这里，测试了假设，即θ带刺激前活动影响海马体内的连续处理。对跨感觉情景记忆的神经元相关性的检查应该反映通常生成这些记忆的丰富环境。因此，在第三部分中，计划在更真实的虚拟现实（VR）环境中测试实验室结果的可靠性和有效性。在现实世界中，情景记忆是在自然环境中编码的，通常是记忆的一部分。 VR 设置非常适合测试更自然的情境记忆的编码以及该情境中跨模式关联的发展。此外，参与者的行为可以在 VR 中详细记录，将行为方面与记忆的形成联系起来。在这里，计划测试自我参与行为和探索行为（头部和眼睛运动）对刺激前振荡状态和记忆编码的影响。因此，在最后的实验中，脑电图将与VR刺激同时测量。