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fMRI证据将多巴胺能中脑区域与人类的奖励预测刺激联系起来。这些被认为或多或少会自动（“自下而上”）招募资源以允许足够的响应。但是，问题仍然是多巴胺能中脑是否在“自上而下”的注意力资源中发挥作用。这样的自上而下的机制必须能够招募由于即将到来的情况和没有任何相关奖励意外事件的预知而招募多巴胺能中脑。一项试点fMRI研究提供了支持该假设的数据。在该实验中，操纵目标刺激歧视的困难，并由目标提示签名，这导致了硬胺中脑对硬任务的反应增强。为了能够令人信服地将这种激活解释为“自上而下”，有必要证明它是为了响应提示本身而不是目标处理任务本身而产生的。因此，第一个项目提出了一项功能磁共振成像研究，该研究将提示引起的活性与目标刺激引起的活动区分开。第二个项目旨在建立一种新的方法，以弥合与注意力相关的功能磁共振成像激活与相应的大脑活动电量测量之间的差距，该方法源自简单记录的EEG和FMRI的测量值。