A monolithic silicon nonlinear lateral inhibition model

Lateral inhibition is a term often used to describe a type of interaction between neural processing units that occupy the same processing layer. The interactions are characterized by processing unit activity tending to inhibit activity in neighbouring processing units. There is strong evidence to suggest that multiplicative lateral inhibition processes are active in the retinal neural layers. Moreover, these multiplicative lateral inhibition processes are responsible for many early vision processing functions such as edge enhancement and contrast enhancement. This paper describes a hardware model for a nonlinear lateral inhibition model. The model is based on a current shunting mechanism. The model was designed to be integrated onto a monolithic piece of silicon. The design is described and the expected features of the modulation transfer function are discussed. The device was fabricated in a 1.5 μm p-well, CMOS process