Investigating the effects of stimulation duration for brain-computer interface

In this paper, the most effective stimulation durations for the purpose of brain-computer interface (BCI) with functional near-infrared spectroscopy (fNIRS) is investigated. To do so, this study investigates the influence of varying stimulation duration on the hemodynamic response (HR) signal in the primary visual cortex of the human brain. fNIRS is used for the measurement of HRs. For brain stimulation, a flickering checkerboard task is utilized, and the HR signals are acquired. Three different stimulation durations, i.e., 1, 3, and 5 secs were used in this study, and a total of 5 subjects participated in the experiment. From the results of the study, it is concluded that among the tested stimulation durations, the HR signal rises with the increase of the stimulation duration. Also, it was found that even the smallest stimulation duration, i.e., 1 sec, can generate a detectable activation in the visual cortex of the brain, which can well serve the purpose of BCI.