In the locust's lobula giant movement detector neural pathways, four categories of inhibition, i.e., global inhibition, self-inhibition, lateral inhibition, and feed-forward inhibition, have been functionally explored in the context of looming perception. However, their combined influence on shaping selectivity to looming motion remains unclear. Driven by recent physiological advancements, this paper offers new insights into the roles of these inhibitory mechanisms at multiple levels and scales in simulations, refining the specific selectivity for responding only to objects approaching the eyes while remaining unresponsive to other forms of movement. Within a feed-forward, multi-layer neural network framework, global inhibition, lateral inhibition, self-inhibition, and feed-forward inhibition are integrated. Global inhibition acts as an immediate feedback mechanism, normalising light intensities delivered by ommatidia, particularly addressing low-contrast looming. Self-inhibition, modelled numerically for the first time, suppresses translational motion. Lateral inhibition is formed by delayed local excitation spreading across a larger area. Notably, self-inhibition and lateral inhibition are sequential in time and are combined through feed-forward inhibition, which indicates the angular size subtended by moving objects. Together, these inhibitory processes attenuate motion-induced excitation at multiple levels and scales. This research suggests that self-inhibition may act earlier than lateral inhibition to rapidly reduce excitation in situ, thereby suppressing translational motion, and global inhibition can modulate excitation on a finer scale, enhancing selectivity in higher contrast range.

翻译：在蝗虫小叶巨运动检测器神经通路中，全局抑制、自抑制、侧抑制和前馈抑制这四类抑制机制已在逼近感知背景下得到功能性探索。然而，它们对塑造逼近运动选择性的综合影响尚不明确。基于近期生理学进展，本文通过多层级、多尺度的仿真研究，为这些抑制机制的作用提供了新见解，从而优化了仅对逼近眼睛的物体产生响应而对其他运动形式保持不响应的特异性选择机制。在前馈式多层神经网络框架中，我们整合了全局抑制、侧抑制、自抑制与前馈抑制。全局抑制作为即时反馈机制，可标准化小眼传递的光强，特别针对低对比度逼近刺激。首次通过数值建模的自抑制机制可有效抑制平移运动。侧抑制则由延迟的局部兴奋在更大范围内扩散形成。值得注意的是，自抑制与侧抑制在时间上呈序贯关系，并通过前馈抑制进行整合——该机制可表征运动物体的对角尺寸。这些抑制过程共同在多层级、多尺度上衰减运动诱导的兴奋。本研究表明：自抑制可能早于侧抑制发挥作用，通过快速原位降低兴奋来抑制平移运动；而全局抑制能在更精细尺度上调节兴奋，从而增强高对比度范围内的选择性。