title: Population coding of saccadic eye movements by neurons in the superior colliculus.
abstract: The deeper layers of the superior colliculus are involved in the initiation and execution of saccadic (high velocity) eye movements. A large population of coarsely tuned collicular neurons is active before each saccade. The mechanisms by which the signals that precisely control the direction and amplitude of a saccade are extracted from the activity of the population are unknown. It has been assumed that the exact trajectory of a saccade is determined by the activity of the entire population and that information is not extracted from only the most active cells in the population at a subsequent stage of neural processing. The trajectory of a saccade could be based on vector summation of the movement tendencies provided by each member of the population of active neurons or be determined by a weighted average of the vector contributions of each neuron in the active population. Here we present the results of experiments in which a small subset of the active population was reversibly deactivated with lidocaine. These results are consistent with the predictions of the latter population-averaging hypothesis and support the general idea that the direction, amplitude and velocity of saccadic eye movements are based on the responses of the entire population of cells active before a saccadic eye movement.
authors.affiliation: Department of Physiology and Biophysics, University of Alabama, Birmingham 35294.
authors.forename: C
authors.initials: C
authors.lastname: Lee
authors.forename: W H
authors.initials: WH
authors.lastname: Rohrer
authors.forename: D L
authors.initials: DL
authors.lastname: Sparks
mesh_terms: D000818:Animals; D005133:Eye Movements / Q000187:drug effects; D008012:Lidocaine / Q000494:pharmacology; D008253:Macaca mulatta; D008959:Models, Neurological; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D012438:Saccades / Q000187:drug effects; D013477:Superior Colliculi / Q000502:physiology*
chemical_list: D008012:Lidocaine