[Abstract Title]. - Society for Neuroscience

predictable or unpredictable (Keith et al. Soc. Neurosci. Abst. 2007). Here, we reexamined the
ability of primates to update saccade targets across SP movements, specifically testing the
hypothesis that if animals are cued when and where SP will end, memory guided saccades will
have lower latency and increased accuracy. To date, a complete behavioral data set has been
obtained from 2-D search coil recordings in one rhesus monkey. The monkey was trained to 1)
fixate a home fixation point 10º from the center in either direction along one of the 4 cardinal
and oblique lines, and 2) then a memory target was flashed at a right angle (in either direction)
from this line, also 10º from centre. 3) Following the memory flash, the fixation target began to
move at 14º/s through the centre position and the animal was required to pursue the target until it
extinguished. 4) At that point the animal had to saccade toward the memory target to obtain a
reward. This created a total combination of 16 general SP-saccade direction pairs. In the un-cued
condition, the pursuit target unpredictably traversed 1-30º before extinguishing, making the exact
direction of the required saccade unpredictable. In the cued condition (a fixation cross instead of
a dot) the SP target always traversed 20º, so in principle saccade direction was predictable.
During initial training only, the SP end point was shown along with the cue to re-enforce this
association. Blocks of cued and un-cued were used in training whereas all testing paradigms
were randomly interleaved. The animal learned to perform all aspects of the spatial updating task
with general accuracy (we required a 6º degree window for the final saccade target), but made
idiosyncratic direction-dependent errors. Comparing between 20º SP runs (368 trials in total) we
found a statistically lower saccade latency (p