Visual object processing in the inferotemporal cortex

描述(申请人提供)：视觉物体识别是我们行为的核心，对大脑潜在机制的了解对于理解人类的视觉感知和记忆至关重要。关键问题是为对象身份创建选择性，允许对象的视网膜图像发生变化，如位置和大小的变化。灵长类动物的大脑似乎在腹侧视觉流中构建了这种选择性，因为在视觉流的最高区域--前额叶下皮质(AIT)--的神经元反应显示出形状的选择性，可以容忍位置和大小的变化。然而，我们并不了解这些关键的神经元特性--关于AIT耐受性的报道有限且不一致，最近的研究表明，AIT耐受性可能非常有限。因此，这项建议的目标是了解可能决定AIT位置和大小耐受的关键因素，并确定AIT耐受是否可以解释行为耐受。 我们的第一个目标是系统地确定一系列目标集合和目标训练历史的AIT神经元形状选择性的位置和大小容差。我们将建立选择性与AIT位置和尺寸公差的关系，AIT位置和尺寸公差的交互作用，以及特定对象训练对这些关系的影响。这些数据将在灵长类视觉系统的最高水平建立神经元耐受性，并为进一步研究提供急需的基础。 可能构成位置和尺寸容差的机制分为两大类：(1)自动概括；(2)通过体验物体在位置和大小上的变化而获得的容差。我们的第二个目标是确定特定位置或大小的物体体验是否对AIT形状选择性的位置或大小容差有实质性影响。由于这一点尚未得到检验，任何结果都将在约束机制和指导未来研究方面提供极大的信息。 虽然AIT耐受性被认为是行为耐受性的基础，但这还没有得到系统的检验。我们的第三个目标是确定物体识别的位置和大小容忍度是否可以用AIT神经元形状选择性的容忍度来解释。这对于理解高水平腹侧流神经元反应和视觉对象识别之间的联系至关重要。

DESCRIPTION (provided by applicant): Visual object recognition is central to our behavior, and knowledge of the underlying brain mechanisms is critical to understanding human visual perception and memory. The key problem is creation of selectivity for object identity that tolerates changes in an object's retinal image, such as changes in position and size. The primate brain appears to construct this selectivity in the ventral visual stream because neuronal responses in the highest area of that stream--the anterior inferotemporal cortex (AIT)--show shape selectivity that can tolerate position and size changes. Yet, we do not understand these key neuronal properties--reports of AIT tolerance are limited and inconsistent, and recent studies show that it can be very restricted. Thus, the goals of this proposal are an understanding of key factors likely to determine AIT position and size tolerance, and to determine if AIT tolerance can explain behavioral tolerance. Our first aim is to systematically determine the position and size tolerance of AIT neuronal shape selectivity for a range of object sets and object training histories. We will establish the relationship of selectivity and AIT position and size tolerance, the interaction of AIT position and size tolerance, and the effect of object-specific training on these relationships. These data will establish neuronal tolerance at the highest level of the primate visual system and provide a much-needed foundation for further study. The mechanisms that might underlie position and size tolerance fall into two broad classes: (1) automatic generalization; and (2) tolerance learned by experiencing objects across changes in position and size. Our second aim is to determine if position- or size-specific object experience have substantial effects on the position or size tolerance of AIT shape selectivity. Because this has not been examined, any result would be extremely informative in constraining mechanisms and guiding future studies. Although it is thought that AIT tolerance underlies behavioral tolerance, this has not been systematically examined. Our third aim is to determine if the position and size tolerance of object identification can be explained by the tolerance of AIT neuronal shape selectivity. This is a vital to understanding the link between high-level, ventral stream neuronal responses and visual object identification.