Mechanisms of top-down visual selection

我们的视觉世界通常包含许多对象，其中只有一些与我们的行为有关。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，并忽略不相关的刺激。引导注意力到相关信息的能力可能在各种神经心理障碍中被破坏，包括单侧忽视。由于忽视等障碍是脑部病变恢复不良的指标，因此了解通常使我们能够有效引导注意力的因素，并利用这些知识指导此类患者的康复是很重要的。我们将开展一项研究计划，以检查功能和神经过程，这些过程使我们能够以自上而下的方式引导注意力。态度，基于内部掌握的信息。为了获得尽可能完整的图像，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）和对离散脑病变患者的神经心理学研究，每一种技术都可以提供有关神经功能的重要信息。一些提供了有关相关大脑区域的精确信息（fMRI），另一些提供了是否需要大脑区域的信息（TMS，病变研究），还有一些提供了有关影响的时间特性的信息（ERPs）。这项工作将评估我们对目标的期望，任务所需的行动，以及工作记忆中携带的信息如何影响注意力。最后，我们将研究提示患者参与所有部分的物体是否可以导致功能从忽视中恢复，为康复研究提供概念证明。

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.