Effect of the combination of different numbers of flickering frequencies in an SSVEP-BCI for healthy volunteers and stroke patients

The steady-state visually evoked potential (SSVEP) is a particular response of the brain observed as an oscillating wave induced by repetitive visual stimulation. This paper focuses on the use of this paradigm for the construction of a brain-computer interface (BCI) system using different numbers of visual stimuli in different frequencies. The responses were analyzed for healthy subjects and stroke patients and show that a suitable choice of stimulation frequencies can be of paramount importance insofar as the system performance is concerned.