Realization of an Artificial Visual Nervous System using an Integrated Optoelectronic Device Array

TLDR

Human behavior relies on complex sensory processing, and sensory adaptation filters irrelevant stimuli, motivating neuromorphic systems that emulate organ‑level functions. The study demonstrates a dynamic, real‑time photoadaptation process in an artificial photoreceptor to enable sensory adaptation in spiking neural networks. The device uses a neurotransistor to convert filtered light signals and adaptation signals into a range of postsynaptic states that vary with environmental conditions. The circuits successfully emulate biological sensory adaptation, adjust sensitivity to light intensity, and show promise for advancing neuromorphic device technology.

Abstract

Human behavior (e.g., the response to any incoming information) has very complex forms and is based on the response to consecutive external stimuli entering varied sensory receptors. Sensory adaptation is an elementary form of the sensory nervous system known to filter out irrelevant information for efficient information transfer from consecutive stimuli. As bioinspired neuromorphic electronic system is developed, the functionality of organs shall be emulated at a higher level than the cell. Because it is important for electronic devices to possess sensory adaptation in spiking neural networks, the authors demonstrate a dynamic, real-time, photoadaptation process to optical irradiation when repeated light stimuli are presented to the artificial photoreceptor. The filtered electrical signal generated by the light and the adapting signal produces a specific range of postsynaptic states through the neurotransistor, demonstrating changes in the response according to the environment, as normally perceived by the human brain. This successfully demonstrates plausible biological sensory adaptation. Further, the ability of this circuit design to accommodate changes in the intensity of bright or dark light by adjusting the sensitivity of the artificial photoreceptor is demonstrated. Thus, the proposed artificial photoreceptor circuits have the potential to advance neuromorphic device technology by providing sensory adaptation capabilities.