Department of BIological Structure, Washington National Primate Research Center, University of Washington, Seattle, United States.
Physiology and Biophysics, Washington National Primate Research Center, University of Washington, Seattle, United States.
Elife. 2017 Sep 19;6:e25784. doi: 10.7554/eLife.25784.
Successful recognition of partially occluded objects is presumed to involve dynamic interactions between brain areas responsible for vision and cognition, but neurophysiological evidence for the involvement of feedback signals is lacking. Here, we demonstrate that neurons in the ventrolateral prefrontal cortex (vlPFC) of monkeys performing a shape discrimination task respond more strongly to occluded than unoccluded stimuli. In contrast, neurons in visual area V4 respond more strongly to unoccluded stimuli. Analyses of V4 response dynamics reveal that many neurons exhibit two transient response peaks, the second of which emerges after vlPFC response onset and displays stronger selectivity for occluded shapes. We replicate these findings using a model of V4/vlPFC interactions in which occlusion-sensitive vlPFC neurons feed back to shape-selective V4 neurons, thereby enhancing V4 responses and selectivity to occluded shapes. These results reveal how signals from frontal and visual cortex could interact to facilitate object recognition under occlusion.
成功识别部分遮挡的物体被认为涉及负责视觉和认知的大脑区域之间的动态相互作用,但缺乏反馈信号参与的神经生理学证据。在这里,我们证明了在执行形状辨别任务的猴子的腹外侧前额叶皮层 (vlPFC) 中,神经元对遮挡的刺激比未遮挡的刺激反应更强烈。相比之下,视觉区域 V4 中的神经元对未遮挡的刺激反应更强烈。对 V4 反应动力学的分析表明,许多神经元表现出两个短暂的反应峰,第二个反应峰出现在 vlPFC 反应开始之后,并对遮挡的形状表现出更强的选择性。我们使用 V4/vlPFC 相互作用的模型复制了这些发现,其中对遮挡敏感的 vlPFC 神经元反馈到形状选择性 V4 神经元,从而增强了 V4 对遮挡形状的反应和选择性。这些结果揭示了来自额叶和视觉皮层的信号如何相互作用,以促进遮挡下的物体识别。