[Abstract Title]. - Society for Neuroscience

suppressed due to non-specific brain activation in association with the neck extensor muscle
activity.
Disclosures: K. Kunita , None; K. Fujiwara, None; M. Katayama, None; H. Watanabe,
None.
Poster
264. Eye Movements: Smooth Pursuit
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 264.1/DD18
Topic: D.06.d. Saccades and Pursuit
Support: National Science Foundation Graduate Fellowship
MH077970
HHMI
Title: Changes in single unit activity in the frontal eye fields (FEFSEM) during pursuit learning
Authors: *J. X. LI, S. G. LISBERGER;
UCSF, San Francisco, CA
Abstract: Repeated exposure to a consistent change in target motion allows the smooth pursuit
eye movement system to rapidly learn to emit an eye movement that predicts the time and
direction of change in target motion (Medina, et.al. 2005). To understand how the neural signals
for learning are represented and modified as they progress through the pursuit circuit, we
recorded from the smooth eye movement region of the frontal eye field (FEFSEM). The
FEFSEM is a motor cortex for pursuit that processes the visual motion input from area MT to
drive downstream structures. Pursuit neurons in the FEFSEM do not respond in a stereotyped
manner to pursuit. Rather, the coding of pursuit is distributed so that each neuron is most active
during specific epochs of the movement (Schoppik, et.al. 2008). This raises the possibility that a
neuron is selectively involved in learning at the time when it is most active.
We recorded from 55 single units in the macaque FEFSEM to explore how these neurons alter
their activity during pursuit learning. In these experiments, the target changed direction 250 ms
after the onset of target motion, and the direction of target change was chosen to match the
neuron's preferred direction. We found that the learning-related changes in responses varied
widely across neurons. The heterogeneity could not be explained by disparities in the magnitude
of the learned behavior, which remained fairly consistent from day to day. Instead, the amount of