[Abstract Title]. - Society for Neuroscience

Disclosures: A. Tavassoli, None; D.L. Ringach , None.
Poster
264. Eye Movements: Smooth Pursuit
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 264.14/DD31
Topic: D.06.d. Saccades and Pursuit
Support: conte center P50 MH077970
HHMI
Title: Single trial learning in smooth pursuit eye movements
Authors: Y. YANG 1 , *S. G. LISBERGER 2 ;
1 Dept. of physiology, HHMI, Keck Ctr. Integrative Neuroscience, UCSF, San Francisco, CA;
2 Dept Physiol, Univ. California Sch. Med., San Francisco, CA
Abstract: Motor skills improve with repeated attempts at the same task. To analyze the dynamic
neural basis of learning, however, we have developed a new approach to study the effect of
instructional stimuli in one behavioral trial on neural responses in the subsequent trial.
Experiments consisted of a sequence of instructional trials where the target always started by
moving in one direction and then, after 250 ms, added an instructional component of motion in
the orthogonal direction. When the starting motion was rightward, the direction of the second,
instructional motion varied randomly to be upward or downward. We then asked how the
direction of the instructional motion on each of 10 previous trials affected the learned eye
movement in a given trial. We found that the most recent trial had a large impact on the learned
eye movement in any given trial, with rapidly decreasing weight given to each earlier trial. In
addition, to the large and rapid learning induced by a single trial, we found a slower, learning
when the same instructional motion was presented repeatedly. Because of the large amount of
single trial learning in pursuit, the results might reflect anticipation rather than learning. To test
this possibility, we presented cues that lasted 50, 150, or 250 ms and consisted of target motion
to the right. As before, the instructional target motion started to move upward or downward 250
ms after the start of the cue. The 250 ms duration cue provided the same target motion used to
demonstrate single trial learning; the shorter cues provided the same information about the time
of the instructional target motion, but engaged pursuit less effectively. If single trial learning
were due to anticipation, then the amount of single trial learning should be independent of cue
duration. If single trial learning represented pursuit motor learning, then we would expect more
learning for longer duration cues. This is what we found. We conclude that a single instructional