Visual Indexes in Spatial Vision and Imagery
Zenon W. Pylyshyn · 1998
Abstract It is a truism that the visual system does some things in parallel and some things serially. The eye moves in rapid saccades several times each second. The centre of the fovea is the centre of our gaze and provides a focus of attention. In addition, attention can also move independently of eye movements. Many people (e.g., Posner, 1980) have shown that a region of most efficient processing can be scanned across the visual field at about 100 degrees/ second when the eye is fixated (published estimates run from 30 to 250 deg/ sec). Much research has been done on this “covert attention movement.” The assumption has generally been made that such focal attention is confined to a contiguous region, possibly expandable in size, that must be scanned over the display from place to place.