Population coding of saccadic eye movements by neurons in the superior colliculus

Nature. 1988 Mar 24;332(6162):357-60. doi: 10.1038/332357a0.


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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Eye Movements* / drug effects
  • Lidocaine / pharmacology
  • Macaca mulatta
  • Models, Neurological*
  • Neurons / drug effects
  • Neurons / physiology*
  • Saccades* / drug effects
  • Superior Colliculi / physiology*


  • Lidocaine