The Positive Components of the Evoked Response to Visual Stimuli in the Saccadic “Go/NoGo” Paradigm in Humans

Resumo

To analyze the mechanisms of voluntary control of oculomotor behavior, including the inhibition processes, we studied the parameters and topography of the positive components of the event-related potential (ERP) to visual stimuli of various signal values in the saccadic “Go/NoGo” paradigm in 19 healthy right-handed subjects. The data we obtained suggest a different functional significance of the positive ERP components depending on the individual magnitude of the latent period (LP) of the saccadic response to the starting stimuli (Go). In the group of fast subjects (LP = 193 ± 10 ms), the Go-P100, Go-P200, and Go-P300 components may reflect the processes of decision-making, response initiation, and behavior monitoring, respectively; in slow subjects (LP = 277 ± 11 ms) they may reflect the processes of stimulus evaluation, decision-making, and response initiation. Regardless of the group of subjects, the NoGo-P100 component reflects the stage of evaluation of the inhibitory stimulus; the NoGo-P200 component reflects the stage of decision-making and saccade inhibition and the NoGo-P300 component reflects the stage of monitoring and analyzing the results of behavior.