REPRESENTATION OF FAMILIAR IMAGES IN VENTRAL STREAM VISUAL CORTEX

我们依靠皮层腹侧流对视觉输入的分层处理来进行物体识别。 视觉区域。该链始于低级皮质（包括V2区），其中神经元活动代表局部 特征并终止于颞下皮层（包括TE区），其中神经元活动代表全局 图像.腹侧流中的神经元功能受视觉体验的影响。一个特别 视觉可塑性的一种强有力的形式是熟悉性抑制。TE中的熟悉性抑制可以通过以下方式诱导： 允许受试者在数天和数周内重复观看同一组图像。结束时 在熟悉期，TE中神经元反应的平均强度对于熟悉的图像小于对于熟悉的图像。 新颖的控制。假设熟悉性抑制是TE特有的，它被认为是 与全局图像的后期处理相关的某些功能。然而，最近， 甚至在V2中也会发生，其中神经元代表局部特征而不是整个对象。上 基于这一观察，我们认为熟悉性抑制，远不是特定于晚期阶段， 全局图像的处理，来自于在每个 阶段的腹流和表达在每个阶段相对于性质和规模的代表视觉 信息.我们将通过使用半慢性多电极阵列来监测神经元， 在图像熟悉期间，V2和TE中的群体活动同时进行。目标1下的实验将测试 熟悉性抑制在V2中独立发展，而不仅仅是来自TE的反馈。 目标2下的实验将检验熟悉增强合作表征的假设 V2和TE中神经元群体的图像。目标3下的实验将测试突触 在熟悉的影响下的改变遵循赫布学习规则。

We rely for object recognition on hierarchical processing of visual input by the ventral stream of cortical visual areas. The chain begins in low-order cortex (including area V2) where neuronal activity represents local features and terminates in inferotemporal cortex (including area TE) where neuronal activity represents global images. Neuronal function in the ventral stream is subject to alteration by visual experience. One particularly robust form of visual plasticity is familiarity suppression. Familiarity suppression can be induced in TE by allowing subjects to view the same set of images repeatedly over the course of days and weeks. At the end of the familiarization period, the mean strength of neuronal responses in TE is less for the familiar images than for novel controls. On the assumption that familiarity suppression is specific to TE, it has been thought to serve some function related to late-stage processing of the global image. Recently, however, familiarity suppression has been shown to occur even in V2, where neurons represent local features and not entire objects. On the basis of this observation, we propose that familiarity suppression, far from being specific to late-stage processing of the global image, arises from principles of unsupervised statistical learning operative at each stage of the ventral stream and expressed at each stage relative to the nature and scale of represented visual information. We will test this general idea by using semi-chronic multielectrode arrays to monitor neuronal population activity simultaneously in V2 and TE during image familiarization. Experiments under Aim 1 will test the hypothesis that familiarity suppression develops independently in V2 and is not just fed back from TE. Experiments under Aim 2 will test the hypothesis that familiarization enhances the cooperative representation of an image by neuronal populations in V2 and TE. Experiments under Aim 3 will test the idea that the synaptic alterations underlying the impact of familiarization obey a Hebbian learning rule.