During active vision, the eyes continually scan the visual
environment using saccadic scanning movements. This target article
presents an information processing model for the control of these
movements, with some close parallels to established physiological
processes in the oculomotor system. Two separate pathways are concerned
with the spatial and the temporal programming of the movement. In the
temporal pathway there is spatially distributed coding and the saccade
target is selected from a “salience map.” Both pathways
descend through a hierarchy of levels, the lower ones operating
automatically. Visual onsets have automatic access to the eye control
system via the lower levels. Various centres in each pathway are
interconnected via reciprocal inhibition. The model accounts for a
number of well-established phenomena in target-elicited saccades: the
gap effect, express saccades, the remote distractor effect, and the
global effect. High-level control of the pathways in tasks such as
visual search and reading is discussed; it operates through spatial
selection and search selection, which generally combine in an automated
way. The model is examined in relation to data from patients with
unilateral neglect.