ABSTRACT

Introduction There is too much potentially useful sensory data available for any biological or man-made computational system to acquire and process all at one time, especially in vision. Visual search and attention represent strategies used by biological systems to come to grips with this very difficult problem. In visual search, information is gathered using a series of eye movements to centre the fovea at selected points of interest. At each fixation the image is encoded in the retina at variable resolution and transmitted to the primary visual cortex (visual area 1 or VI), via the lateral geniculate nucleus (LGN) (Van Essen and Anderson, 1990). A very complex process then begins in VI dealing with questions such as how much of the new image data, in what form, and where it is to be delivered in the brain for detailed processing. These are the elements of visual attention.