Selective attention is a mechanism used to sequentially select and process
salient subregions of the input space, while suppressing inputs arriving fr
om nonsalient regions. By processing small amounts of sensory information i
n a serial fashion, rather than attempting to process all the sensory data
in parallel, this mechanism overcomes the problem of flooding limited proce
ssing capacity systems with sensory inputs. It is found in many biological
systems and can be a useful engineering tool for developing artificial syst
ems that need to process in real-time sensory data. In this paper we presen
t a neuromorphic hardware model of a selective attention mechanism implemen
ted on a very large scale integration (VLSI) chip, using analog circuits. T
he chip makes use of a spike-based representation for receiving input signa
ls, transmitting output signals and for shifting the selection of the atten
ded input stimulus over time. It can be interfaced to neuromorphic sensors
and actuators, for implementing multichip selective attention systems. We d
escribe the characteristics of the circuits used in the architecture and pr
esent experimental data measured from the system.