Human Cerebral Cortex Initiation Potentials Preceding Memory-Guided Saccades
Differences in the parameters of memory-guided saccades and saccades to visual stimuli were demonstrated. Increases in the latent periods of memory-guided saccades as compared with saccades to visual stimuli provided evidence of slowing of saccade programming based on the extraction of information from working memory. Differently directed lateral differences were seen in the latent periods and durations of saccades to visual targets and memory-guided saccades, reflecting the leading role of the left hemisphere in the programming of saccades to visual stimuli and the right hemisphere in the programming of memory- guided saccades. Comparison of parameters of the temporospatial dynamics of initiation potentials P-1 and N-1, which develop in the last 100 msec of the latent periods of saccades, suggest that there are different mechanisms for the final step of programming saccades to visual stimuli and memory-guided saccades. Decreases in the latent period of the P-1 and N-1 peak potentials before memory-guided saccades may be evidence showing acceleration of the initiation processes for memory-guided saccades as compared with visually evoked saccades. This provides grounds for suggesting that the slowing of the programming of memory-guided saccades occurs at steps preceding saccade initiation.