Analog VLSI Excitatory Feedback Circuits for Attentional Shifts and Tracking

Abstract: In this paper we present analog very large-scale integrated (VLSI) circuits that perform the selection process for attentive visual processing. These circuits use excitatory feedback in a winner-take-all computation to produce a hysteresis in the selection from one location to the next. We present several alternative forms of excitation that can be used to enhance surrounding regions of the presently attended location. Each form of excitation is discussed and experimental results from a one-dimensional array are presented. We also demonstrate the performance of these circuits within a system that receives optical inputs and outputs a single voltage that encodes the position of attention. The system demonstrates the potential use of these excitatory feedback circuits for electronic tracking of a stimulus within a noisy environment.