Feedback is crucial to motion perception in animals' visual systems where its spatial and temporal dynamics are often shaped by movement patterns of surrounding environments. However, such spatio-temporal feedback has not been deeply explored in designing neural networks to detect small moving targets that cover only one or a few pixels in image while presenting extremely limited visual features. In this paper, we address small target motion detection problem by developing a visual system with spatio-temporal feedback loop, and further reveal its important roles in suppressing false positive background movement while enhancing network responses to small targets. Specifically, the proposed visual system is composed of two complementary subnetworks. The first subnetwork is designed to extract spatial and temporal motion patterns of cluttered backgrounds by neuronal ensemble coding. The second subnetwork is developed to capture small target motion information and integrate the spatio-temporal feedback signal from the first subnetwork to inhibit background false positives. Experimental results demonstrate that the proposed spatio-temporal feedback visual system is more competitive than existing methods in discriminating small moving targets from complex dynamic environment.
翻译:在动物的视觉系统中,其空间和时空动态往往受周围环境的移动模式影响,对移动感知系统进行感知至关重要。然而,在设计神经网络以探测只覆盖图像中一个或几个像素的小型移动目标,同时呈现极为有限的视觉特征时,这些时空回馈没有进行深入探索。在本文中,我们通过开发一个带有时空脉冲反馈环的视觉系统来解决小目标运动探测问题,并进一步揭示其在抑制虚假正面背景运动,同时加强对小目标的网络反应方面发挥的重要作用。具体地说,拟议的视觉系统由两个互补的子网络组成。第一个子网络旨在提取神经元共感拼凑背景的时空运动模式。开发第二个子网络是为了捕捉小目标运动信息,并整合第一个子网络的瞬时空反馈信号,以抑制背景假积极因素。实验结果表明,在区分从复杂的动态环境中移动的小目标时,拟议的时空反馈系统比现有方法更具竞争力。