Untersuchung des dopaminergen Einflusses auf visuelle Aufmerksamkeit mittels EEG, fMRI und der Kombination beider Methoden mittels Einzel-trial-basierter Analyse

使用脑电图、功能磁共振成像以及基于单一试验的分析结合两种方法研究多巴胺能对视觉注意力的影响

• 批准号: 102212716
• 负责人: Professor Dr. Carsten Nicolas Böhler
• 金额: --
• 依托单位: Center of Cognitive Neuroscience (CCN)
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/102212716?language=en
• 关键词: Untersuchung; des; dopaminergen; Einflusses; auf

Recently, a large body of fMRI evidence has linked dopaminergic midbrain areas to the processing of reward-predicting stimuli in humans. These are thought to more or less automatically (“bottom-up”) recruit processing resources to allow for an adequate response. The question remains, however, whether the dopaminergic midbrain also plays a role in “top-down” recruitment of attentional resources. Such a top-down mechanism would have to be able to recruit the dopaminergic midbrain due only to foreknowledge about an upcoming situation and in the absence of any associated reward contingencies. A pilot fMRI study provides data in support of this hypothesis. In this experiment, the difficulty of target stimulus discrimination was manipulated, and signaled by a pre-target cue, which resulted in enhanced responses in the dopaminergic midbrain for the hard-task. In order to be able to convincingly interpret this activation as “top-down”, it is necessary to demonstrate that it arises in response to the cue by itself, rather than by the target processing task itself. Therefore, the first project proposes an fMRI study that distinguishes activity elicited by the cue from that elicited by the target-stimuli. The second project seeks to establish a novel approach to bridge the gap between the attention-related fMRI activations and corresponding electrical measures of brain activity, derived from the integration of simultaneously recorded measurements of EEG and fMRI.

最近，大量的功能磁共振成像证据表明，多巴胺能中脑区域与人类对奖励预测刺激的处理有关。这些被认为或多或少自动（“自下而上”）招募处理资源，以允许适当的响应。然而，问题仍然存在，多巴胺能中脑是否也在“自上而下”的注意力资源的招募中发挥作用。这种自上而下的机制必须能够招募多巴胺能中脑，因为只有预知即将到来的情况，并且没有任何相关的奖励意外事件。一项初步的fMRI研究提供了支持这一假设的数据。在这个实验中，目标刺激识别的难度被操纵，并通过前目标线索发出信号，这导致多巴胺能中脑对硬任务的反应增强。为了能够令人信服地解释这种激活为“自上而下”，有必要证明它是在对线索本身的反应中产生的，而不是由目标处理任务本身产生的。因此，第一个项目提出了一项功能磁共振成像研究，该研究将线索引发的活动与目标刺激引发的活动区分开来。第二个项目旨在建立一种新的方法来弥合注意力相关的功能磁共振成像激活和相应的大脑活动的电测量之间的差距，来自同时记录的EEG和功能磁共振成像测量的整合。