Carnegie Mellon University.
J Cogn Neurosci. 1996 Fall;8(4):311-27. doi: 10.1162/jocn.1996.8.4.311.
We propose a neural model for object-oriented attention in which various visual stimuli (shapes, colors, letters, etc.) are represented by competing, mutually inhibitory, cell assemblies. The model's response to a sequence of cue and target stimuli mimics the neural responses in infero temporal (IT) visual cortex of monkeys performing a visual search task: enhanced response during the display of the stimulus, which decays but remains above a spontaneous rate after the cue disappears. When, subsequently, a display consisting of the target and several distractors is presented, the activity of all stimulus-driven cells is initially enhanced. After a short period of time, however, the activity of the cell assembly representing the cue stimulus is enhanced while the activity of the distractors decays because of mutual competition and a small top-down "expectational" input. The model fits the measured delayed activity in IT-cortex, recently reported by Chelazzi, Miller, Duncan, and Desimone (1993a), and we suggest that such a process, which is largely independent of the number of distractors, may be used by the visual system for selecting an expected target (appearing at an uncertain location) among distractors.
我们提出了一种面向对象注意力的神经模型，其中各种视觉刺激（形状、颜色、字母等）由相互竞争、相互抑制的细胞集合来表示。该模型对一系列提示和目标刺激的反应模拟了猴子在执行视觉搜索任务时下颞（IT）视觉皮层的神经反应：在刺激显示期间增强反应，在提示消失后反应衰减但仍高于自发率。随后，当呈现由目标和几个干扰物组成的显示时，所有受刺激驱动的细胞的活动最初都会增强。然而，在短时间后，由于相互竞争和少量自上而下的“预期”输入，代表提示刺激的细胞集合的活动得到增强，而干扰物的活动则减弱。该模型符合 Chelazzi、Miller、Duncan 和 Desimone（1993a）最近报告的 IT 皮层中测量到的延迟活动，我们认为，这种在很大程度上与干扰物数量无关的过程可能被视觉系统用于在干扰物中选择预期的目标（出现在不确定的位置）。
