Mechanisms of top-down visual selection

我们的视觉世界通常包含许多对象，其中只有一部分与我们的行为相关。为了在这样的环境中生存，我们需要有效地选择相关的信息，而忽略不相关的刺激。将注意力引导到相关信息上的能力可能会在各种神经心理障碍中中断，包括单边忽视。由于忽视等障碍是脑损伤恢复不良的指标，因此了解通常允许我们有效引导注意力的因素并使用这些知识来指导此类患者的康复是很重要的。我们将进行一项研究计划，以检验使我们能够自上而下地集中注意力的功能和神经过程。方式，根据内部掌握的信息。为了尽可能全面地了解情况，我们将使用各种神经科学技术，包括功能磁共振成像(FMRI)、诱发电位反应(ERPs)、经颅磁刺激(TMS)和对离散脑损伤患者的神经心理学研究，每一项技术都可以提供关于神经功能的重要信息？一些提供了有关精确涉及的大脑区域的信息(FMRI)，另一些提供了是否需要大脑区域的信息(TMS，病变研究)，还有一些提供了影响的时间特性(ERPs)。这项工作将评估我们对目标的期望如何，任务所需的行动如何，以及工作记忆中携带的信息如何影响注意力。最后，我们将研究暗示患者是否可以从忽视中恢复功能，为康复研究提供概念上的证据。

Our visual world often contains many objects, only some of which are relevant to our behaviour. To survive in such an environment, we need to efficiently select the relevant information and to disregard stimuli that are irrelevant. The ability to direct attention to relevant information can be disrupted in a variety of neuropsychological disorders, including unilateral neglect. Since disorders such as neglect are indicators of poor recovery from a brain lesion, it is important to understand the factors that normally allow us to guide attention efficiently, and also to use this knowledge to guide the rehabilitation of such patients. We will conduct a programme of research to examine the functional and neural processes that allow us to direct attention in a ?top-down? manner, based on information held internally. To gain as full a picture as we can, we will use a variety of neuroscientific techniques including functional magnetic resonance imaging (fMRI), evoked potential responses (ERPs), trans-cranial magnetic stimulation (TMS) and neuropsychological studies of patients with discrete brain lesions, each of which can provide important pieces about neural function ? some providing information about the precise brain areas involved (fMRI), others about whether the brain regions are needed (TMS, lesion studies), and others about the temporal properties of the effects (ERPs). This work will assess how our expectancies of targets, how the action required by the task, and how information carried in working memory influences attention. We will finally examine whether cueing patients to attend across all the parts of objects can lead to functional recovery from neglect, providing proof of concept for rehabilitation studies.