The relationship between reaction time and response variability and somatosensory No-go potentials.

We investigated the relationship between reaction time (RT) and response variability and somatosensory Go/No-go potentials. Event-related potentials following electrical stimulation of the second (Go stimulus) or fifth (No-go stimulus) digit of the left hand were recorded from 16 subjects, and Go and No-go stimuli were presented at an even probability. The subjects were instructed to respond to the Go stimuli by pushing a button with their right thumb. We analyzed the correlation between RT and the N140 and P300 components, and between the standard deviation (SD) of RT and the N140 and P300. Neither the amplitude nor latency of the No-go-N140 (N140 evoked by No-go stimuli) or the Go-N140 (N140 evoked by Go stimuli) related significantly with RT and the SD of RT. There was a significant negative correlation between RT and the amplitude of the No-go-P300 (P300 evoked by No-go stimuli) at Fz and C3, indicating that subjects with a shorter RT had a No-go-P300 of larger amplitude. The latency of the Go-P300 (P300 evoked by Go stimuli) at Pz and C3 showed a significant correlation with RT. The SD of RT was significantly correlated with the amplitudes of the No-go-P300 at C3 and Go-P300 at Pz and C4, and the latency of the No-go-P300 at Cz and Go-P300 at Fz, Cz, Pz, C3, and C4. Our results suggest that response speed and variability for the Go stimulus in Go/No-go paradigms affect No-go-related neural activity for the No-go stimulus.