Adaptive Motion Detectors Inspired By Insect Vision

Introduction Inventions such as miniature unmanned aerial vehicles would extend our capabilities in a variety of areas and are a major focus of active research. Before their promise can be reached, however, significant challenges in guidance and control, flight mechanisms, and energy storage must be overcome. Engineers and scientists are turning to animals, particularly insects, for inspiration about how evolution has solved these problems. Our group believes that understanding the visual system of the fly will provide solutions for building a small and efficient visual system suited for real-time flight control. We are therefore investigating the algorithms used in visual motion detection and course stabilization implemented in neural hardware by the fly and translating the concepts into software and analog, “neuromorphic” VLSI electronic implementations. The present work shows that flies implement an adaptive contrast gain control on visual signals before performing motion detection, resulting in neural responses that signal velocity largely independently of overall contrast in the visual input. Additionally, we describe a circuit that implements a proposed mechanism of adaptive contrast gain control based on our neurobiological findings.