The proposed experiments are novel and innovative studies of the neural basis of saccadic target section. The experiments combine McPeek's doctoral work on saccades and attention in visaul search with recordings from collicular neurons in an attempt to determine the role of these neurons in target selection. The experiments rely on a priming method in which saccadic latencies are found to reduce over consecutive trials with the same target color. Changing the target color produces either an increase in latency or sometimes an unusual saccadic pattern in which a saccade directed toward the old color is interrupted and a new, correct saccade initiated after only a 20 msec pause. The candidate proposes to monitor collicular activity during the task and find out the extent to which neural activity corresponds to the location of attended distractors vs. the actual saccadic target. Prior investigators have examined questions of this sort but with simpler and more restrictive behavioral tasks. The proposal would seem to be an improvement over this prior work because the latencies and trajectories of saccades provide behavioral evidence of attention to the distractors. Thus, a more precise dissociation of saccade- and attention-related activity becomes possible.
| Keller, E L; McPeek, R M; Salz, T (2000) Evidence against direct connections to PPRF EBNs from SC in the monkey. J Neurophysiol 84:1303-13 |
