PT  - JOURNAL ARTICLE
AU  - Lynne Kiorpes
AU  - Pamela J. Walton
AU  - Lawrence P. O’Keefe
AU  - J. Anthony Movshon
AU  - Stephen G. Lisberger
TI  - Effects of Early-Onset Artificial Strabismus on Pursuit Eye Movements and on Neuronal Responses in Area MT of Macaque Monkeys
AID  - 10.1523/JNEUROSCI.16-20-06537.1996
DP  - 1996 Oct 15
TA  - The Journal of Neuroscience
PG  - 6537--6553
VI  - 16
IP  - 20
4099  - http://www.jneurosci.org/content/16/20/6537.short
4100  - http://www.jneurosci.org/content/16/20/6537.full
SO  - J. Neurosci.1996 Oct 15; 16
AB  - In humans, esotropia of early onset is associated with a profound asymmetry in smooth pursuit eye movements. When viewing is monocular, targets are tracked well only when they are moving nasally with respect to the viewing eye. To determine whether this pursuit abnormality reflects an anomaly in cortical visual motion processing, we recorded eye movements and cortical neural responses in nonamblyopic monkeys made strabismic by surgery at the age of 10–60 d. Eye movement recordings revealed the same asymmetry in the monkeys’ pursuit eye movements as in humans with early-onset esotropia. With monocular viewing, pursuit was much stronger for nasalward motion than for temporalward motion, especially for targets presented in the nasal visual field. However, for targets presented during ongoing pursuit, temporalward and nasalward image motion was equally effective inmodulating eye movement. Single-unit recordings made from the same monkeys, under anesthesia, revealed that MT neurons were rarely driven binocularly, but otherwise had normal response properties. Most were directionally selective, and their direction preferences were uniformly distributed. Our neurophysiological and oculomotor measurements both suggest that the pursuit defect in these monkeys is not due to altered cortical visual motion processing. Rather, the asymmetry in pursuit may be a consequence of imbalances in the two eyes’ inputs to the “downstream” areas responsible for the initiation of pursuit.