ИСТИНА

In 17 healthy right-handed subjects P1 and P2 ERP components have been studied in GO/NO GO saccadic paradigm. Parameters and topography of these potentials depended on the saccade latency (LP). The subjects were divided into two groups: “slow” subjects (LP=287 ± 13 ms) and “fast” subjects (LP=193 ± 10 ms). In “fast” group Go P2 was corresponded to the spike potential and was excluded from analysis. In “slow” group Go P2 were enhanced compare to P1 and was not differ from Go P1 in ”fast” group. These potentials emerged in the time period 50 - 100 ms prior to saccade onset, and we suppose that they are a marker of saccade programming decision making stage. In all subjects No go P2 was enhanced compare to the No go P1. We also assume that No go P2 ERP reflects decision making process that does not depend on the stimuli significance. The nature of decision making (Go or No go) may be reflected in the opposite direction of P2 foci spreading along the fronto-parietal networks of saccadic control: «top-down» in the «Go» conditions and «bottom-up» in the «No go» conditions, as EEG mapping have been shown. In “slow” group the No go P1 was reduced compare to Go P1. Its peak was mostly located over the centro -parietal- areas of the right hemisphere that may suggest the reflection of inhibition influence on the early stages of sensory stimulus evaluation.