Abstract

In spite of the fact that the computing architecture of the brain is massively parallel, our ability to process incoming sensory information in parallel is surprisingly limited. It is not possible, for example, to recognize within the same instant more than one or two objects in a crowded scene. Thus, much of the information impinging on the retina must be filtered out centrally, a process usually termed attention. To understand how this comes about, we have recorded from neurons in visual areas of monkey extrastriate cortex known to underlie object recognition. We have found that selective attention serves to remove irrelevant information from the receptive fields of extrastriate neurons and sharpen their selectivity for visual features such as orientation or color. These effects of attention may explain both why we have little awareness of unattended stimuli, and why our resolution of spatial location and visual features is improved inside the focus of attention. Our behavioral studies in monkeys suggest that attention controls visual processing via signals from the lateral pulvinar nucleus of the thalamus.

© 1989 Optical Society of America