The superior colliculus and eye movement control.

Saccade metrics are largely determined by command signals generated in the superior colliculus. Recent work has improved our knowledge of the highly complex axonal trees that disseminate these signals. It has also demonstrated that electrical stimulation of the superior colliculus evokes slow (drifts) as well as fast (saccades) eye movements and has provided detailed quantitative descriptions of their metrical properties. New biologically influenced models of the superior colliculus provide a detailed and realistic account of the discharge of tectal pre-saccadic neurons, the properties of evoked saccades and the ability of subjects to execute correct saccades in a variety of circumstances.