Abstract: DESCRIPTION (provided by applicant):
Smooth pursuit is a voluntary eye movement that is used to view objects as they move. Although physiologists have studied many aspects of voluntary saccade control, most work on the neural control of pursuit has treated this system as if it responds reflexively to retinal-image motion.

The pursuit system of primates is a sophisticated ocular movement system that has evolved to allow it to predict when and where an object will move, and to decide whether or not to pursue that object. The focus of the current grant period is to understand how the cortical eye fields cooperate to control voluntary smooth pursuit eye movements.

Aims are to: 1. Compare the strength of predictive and retinal-image signals used by the cortical eye fields to execute a pursuit eye movement 2. Determine how the cortical eye fields interact to cancel a pursuit movement. 3. Determine how the decision is made to execute or cancel a pursuit movement.

The results of these experiments should contribute to our knowledge of how the cortex moves the eyes to effectively view moving objects in the natural scene. The results of this work should provide basic data to facilitate diagnosis and treatment of disorders of vision such as strabismus and amblyopia, and to develop prosthetic devices to aid people who suffer from these disorders.

Thesaurus Terms: neural information processing, smooth pursuit eye movement, visual cortex computer program /software, neuron, neuroregulation, oculomotor nuclei, visual field, visual stimulus
Macaca mulatta, behavior test, computer data analysis, electrophysiology, electrostimulus, microelectrode, single cell analysis, vision test

Institution: SMITH-KETTLEWELL EYE RESEARCH INSTITUTE
SAN FRANCISCO, CA 94115
Fiscal Year: 2006
Department:
Project Start: 01-MAR-1997
Project End: 31-AUG-2008
ICD: NATIONAL EYE INSTITUTE
IRG: VISB

J Neurophysiol 94: 1385-1391, 2005. First published May 11, 2005; doi:10.1152/jn.00109.2005 0022-3077/05 $8.00

Trajectory Interpretation by Supplementary Eye Field Neurons During Ocular Baseball

Yong-Guk Kim¹,², Jeremy B. Badler¹ and Stephen J. Heinen<sup>1

1</sup>The Smith-Kettlewell Eye Research Institute, San Francisco, California; and ²School of Computer Engineering, Sejong University, Seoul, Korea

Submitted 31 January 2005; accepted in final form 19 April 2005

METHODS

Two male rhesus monkeys (Macaca mulatta; referred to as GU and SA) weighing between 5 and 7 kg were used in the study. All procedures were approved by the Institutional Animal Care and Use Committee and were in compliance with the guidelines set forth in the United States Public Health Service Guide for the Care and Use of Laboratory Animals.

Monkeys had scleral coils, head restraint devices, and recording chambers implanted previously (Missal and Heinen 2001 ). Chambers were both located 24 mm anterior (Horsley-Clark coordinates), centered on the midline for GU and 5 mm right of the midline for SA.

Monkeys were seated in a primate chair with head fixed 40 cm from a tangent screen in a dimly lit room. The baseball target was a 0.5° bluish-white spot of light (luminance = 2 cd/m2) projected by an oscilloscope onto the screen (luminance = 0.05 cd/m2). The fixation point was a 0.5° red spot generated by a projection LED. The strike zone was a clearly visible 12°-wide white square, displayed in the center of the screen with a slide projector for the entire trial.