Neural Correlates of Visual Object-Substitution Masking

描述(由申请人提供)：这项研究提案将解决视觉注意如何有助于构建物体的持久表征的基本问题，从而允许人类和其他灵长类动物利用不再可用的信息。为了研究这一一般性问题，将研究最近引入的对象替换掩蔽范式。两个一般性的问题将被问到：(1)单个神经元的活动是否表明，行为相关的项目是由注意力选择的，即使它们没有被处理到准确指导行为的程度？(2)在神经活动的时刻到时刻的调制中，是否可以观察到随后的掩膜取代了目标？物体替换掩蔽已经被证明与注意力在视觉环境中的分配方式直接相关，因为只有当视野中的项目之间存在强烈的竞争时，才会观察到对象替换掩蔽，并且可以通过预先将注意力引导到目标位置来减少或消除对象替换掩蔽。因此，这个项目中的实验将需要猴子在相似的分心物形状中搜索目标形状。在一定比例的试验中，目标和几个干扰物将被四个点包围，这些点应该可以有效地掩盖物品在物体本身消失后仍然可见的情况。增加对注意力和这种新的掩饰形式之间相互作用的理解，最终可能有助于我们理解正常认知处理的障碍，如注意力缺陷障碍。

DESCRIPTION (provided by applicant): This research proposal will address the fundamental issue of how visual attention contributes to the construction of enduring representations of objects allowing humans and other primates to make use of information that is no longer available. To investigate this general issue, the recently introduced object-substitution masking paradigm will be studied. Two general questions will be asked: (1) Does the activity of single neurons suggest that behaviorally relevant items are selected by attention even though they are not processed to the point of accurately guiding behavior? (2) Can the substitution of a target by a subsequent mask be observed in the moment-to-moment modulation of neural activity? Object-substitution masking has been shown to be directly related to how attention is deployed in the visual environment because it is only observed when there is strong competition between items in the visual field, such as in visual search task, and can be reduced or eliminated by precuing attention to the target location. Thus, the experiments in this project will require monkeys to search for a target shape among similar distractor shapes. On a proportion of trials the target and several distractors will be presented surrounded by four dots that should effectively mask the items when they remain visible after the objects themselves disappear. An increased understanding of interactions between attention and this new form of masking may ultimately help us understand disorders of normal cognitive processing such as in attention deficit disorder.