ACTION-MEDIATED VISUAL ATTENTION IN THE HUMAN BRAIN

关注环境中与我们的行为目标相关的刺激的能力对生存至关重要。到目前为止，大多数关于决定视觉注意力的因素的研究都集中在吸引注意力的刺激的基本属性上，例如，它们的大小、方向或颜色对比度。我们最近已经证明，除了这些基本属性外，注意力还取决于对象之间存在的动作关系。例如，对多种刺激有困难的神经科患者发现，如果这些物体看起来好像在一起使用，就更容易做到这一点(Riddoch等人，自然神经科学，2003)。这些数据对于理解注意力是如何运作的可能是至关重要的，而且不仅与评估人类注意力有关，而且还与人工注意力系统的设计有关。在计划中的项目中，我们的目标是评估对象之间的动作关系是否会影响正常观察者的注意力分配，以表明先前的结果对脑损伤人群并不“特殊”。然后，我们将继续探索动作效应的神经基础。功能磁共振(FMRI)成像将用于评估哪些大脑区域对动作信息做出反应，以及是否存在大脑区域网络(包括大脑皮层的主要感觉区域)的调制。功能磁共振成像将告诉我们这些动作效应在大脑中的空间定位，但它提供了关于迅速出现的任何效应的粗略信息。为了检验作用效果的时间进程，我们将记录与事件相关的大脑电位，这将产生影响发生的时间的详细图像。最后，经颅磁刺激将被用来影响目标大脑区域正在进行的神经过程(通过功能磁共振识别)，以测试这些区域是否对注意力的行动效应的出现是必要的。这些结果将使我们能够构建一个关于行为对人类注意力影响的详细的神经和功能解释。

The ability to attend to stimuli in the environment that are relevant to our behavioural goals is crucially important for survival. To date, most studies into the factors that determine visual attention have concentrated on the basic properties of stimuli to which attention is drawn / for example, their size, orientation, or colour contrast. We have recently shown that, in addition to these basis properties, attention is also determined by the presence of action relations between objects. For example, neurological patients who have problems attending to multiple stimuli find it easier to do so if the objects appear as if in use together (Riddoch et al., Nature Neurosci., 2003). These data may be fundamentally important for understanding how attention operates, and would be relevant not only to evaluating human attention but also for the design of artificial attention systems. In the planned project we aim to assess if action relations between objects affect the allocation of attention in normal observers, to show that prior results are not 'special' to brain injured populations. We will then proceed to explore the neural basis for the action effects. Functional magnetic resonance (fMRI) imaging will be used to assess which brain regions respond to action information, and whether there is modulation of a network of brain regions (including primary sensory regions of the cortex). fMRI will inform us about the spatial localisation of these action effects in the brain, but it provides coarse information about quickly any effects emerge. To examine the time course of action effects, we will record event-related brain potentials, which generate a detailed picture of the time at which effects arise. Finally, transcranial magnetic stimulation will be used to affect ongoing neural processes in targeted brain regions (identified through fMRI), to test whether these regions are necessary for action effects on attention to emerge. The results will enable us to construct a detailed neural and functional account of the effects of action on human attention.