The study investigated the role of top-down versus bottom-up connectivity, during the processing of implicit or explicit predictive information, in Parkinson’s disease (PD). EEG was recorded during the performance of a task, which evaluated the ability to utilize either implicit or explicit predictive contextual information in order to facilitate the detection of predictable versus random targets. Thus, subjects performed an implicit and explicit session, where subjects were either unaware or made aware of a predictive sequence that signals the presentation of a subsequent target, respectively. We evaluated EEG event-related directed connectivity, in PD patients compared with healthy age-matched controls, using phase transfer entropy. PD patients showed increased top-down frontal-parietal connectivity, compared to control subjects, during the processing of the last (most informative) stimulus of the predictive sequence and of random standards, in the implicit and explicit session, respectively. These findings suggest that PD is associated with compensatory top-down connectivity, specifically during the processing of implicit predictive stimuli. During the explicit session, PD patients seem to allocate more attentional resources to non-informative standard stimuli, compared to controls. These connectivity changes shed further light on the cognitive deficits, associated with the processing of predictive contextual information, that are observed in PD patients.

该研究调查了自上而下与自下而上连接在处理隐式或显式预测信息期间在帕金森病 (PD) 中的作用。在执行任务期间记录 EEG，评估利用隐式或显式预测上下文信息的能力，以促进检测可预测目标与随机目标。因此，受试者执行了隐式和显式会话，其中受试者要么不知道，要么意识到分别表示后续目标出现的预测序列。我们使用相转移熵评估了 PD 患者与健康年龄匹配的对照组的 EEG 事件相关的定向连接。与对照组相比，PD 患者表现出自上而下的额顶叶连通性增加，在分别在隐式和显式会话中处理预测序列和随机标准的最后（信息量最大）刺激期间。这些发现表明 PD 与自上而下的补偿性连接相关，特别是在处理内隐预测刺激时。在显式会话期间，与对照组相比，PD 患者似乎将更多的注意力资源分配给非信息性标准刺激。这些连接性变化进一步阐明了在 PD 患者中观察到的与预测性上下文信息的处理相关的认知缺陷。这些发现表明 PD 与自上而下的补偿性连接相关，特别是在处理内隐预测刺激时。在显式会话期间，与对照组相比，PD 患者似乎将更多的注意力资源分配给非信息性标准刺激。这些连接性变化进一步阐明了与 PD 患者中观察到的预测性上下文信息的处理相关的认知缺陷。这些发现表明 PD 与自上而下的补偿性连接相关，特别是在处理内隐预测刺激时。在显式会话期间，与对照组相比，PD 患者似乎将更多的注意力资源分配给非信息性标准刺激。这些连接性变化进一步阐明了在 PD 患者中观察到的与预测性上下文信息的处理相关的认知缺陷。