Neural Correlates of Visual Object-Substitution Masking

描述（由申请人提供）：本研究提案将解决视觉注意力如何有助于构建持久的物体表征的基本问题，使人类和其他灵长类动物能够利用不再可用的信息。为了研究这个普遍的问题，我们将研究最近引入的对象替换掩蔽范式。我们将提出两个一般性的问题：（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，即使它们没有被加工到准确指导行为的程度？(2)在神经活动的即时调制中，是否可以观察到目标被随后的掩蔽所替代？对象替代掩蔽被证明与视觉环境中的注意力如何部署直接相关，因为它仅在视野中的项目之间存在强烈竞争时才被观察到，例如在视觉搜索任务中，并且可以通过将注意力预先转移到目标位置来减少或消除。因此，本项目中的实验将要求猴子在类似的干扰物形状中寻找目标形状。在一定比例的试验中，目标和几个干扰物将被四个点包围，这些点在物体本身消失后仍然可见时应该有效地掩盖物体。对注意力和这种新形式的掩蔽之间的相互作用的进一步理解可能最终有助于我们理解正常认知过程的障碍，例如注意力缺陷障碍。

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.