Investigation of habitual characteristics of visual GO-nogo taskusing event-related potentials

In cognitive electrophysiology, the Go-NoGo paradigm which includes both Go stimulus requiring response and NoGo stimulus requiring no response is an experimental design used to observe both response activation and response inhibition processes in the brain. In studies, Go-NoGo paradigms that mostly include Go and NoGo stimuli with frequencies of 0.5 are used, although in some studies, the frequency of Go and NoGo stimuli can vary between 0.2 and 0.8. In this study, we aimed to investigate the effects of application periods and frequencies of Go and NoGo stimuli on the habituation of Go and NoGo responses using an equiprobable visual Go-NoGo paradigm. Event-related potentials (ERPs) were recorded using the visual Go-NoGo paradigm via 12 electrodes from 20 healthy male volunteers aged 19 to 23 years. While the frequencies of Go stimuli in the paradigm were 0.33, 0.67, 0.33 and 0.67 consecutively in the quarter periods of the paradigm, the frequencies of the No-Go stimuli varied as follows 0.67, 0.33, 0.67 and 0.33 in the same periods. The frequencies of the Go and No-Go stimuli in the first and last half of the paradigm and the frequencies of the Go and No-Go stimuli in the overall paradigm were equal to each other (0.5/0.5). Go and NoGo stimuli were presented in a pseudo-random order. Visual stimuli were presented in a pseudo-random series with inter-stimulus intervals (ISI) of 1.5 s. The amplitude and latency of the Go and NoGo responses in both the first and last half of the task in the paradigm and each frequency period were measured and then analyzed by ANOVA for repeated measurements. Our statistical analysis results showed that both Go-P3 and NoGo-P3 potential amplitudes were significantly lower in the last half of the task compared to the first half of the task at all electrode sites (p=0.018 and p=0.031, respectively). Also, it was determined that the Go-P3 potential amplitudes were lower in the periods when the Go stimuli frequency was high, while the NoGo-P3 potential amplitudes were lower in the periods when the NoGo stimuli frequency was high (p=0.003 and p=0.007, respectively). Our results indicated that both Go-P3 and NoGo-P3 potentials were habituated at all recorded electrode sites. In electrophysiological studies using the visual Go-NoGo paradigm, it should be taken into account that both Go-P3 and NoGo-P3 potentials and motor responses will be habituated even if the duration of the paradigm is short. We can say that the differences in local frequencies are important as well as the total frequencies of the stimuli in the Go-NoGo paradigm.