Dante Smith¹, Cara Stepp², Frank Guenther³
¹BU GPN, ²Boston University, ³Boston University
Many proposed EEG-based brain-computer interfaces (BCIs) make use of visual stimuli to elicit steady-state visual evoked potentials (SSVEP). By focusing their visual attention to a flashing light of a specific frequency, a participant’s visual cortex activity entrains to that frequency. This oscillatory activity can be detected via EEG and translated to a computer input. However, such a control scheme can be ineffective if a user has no motor control over their eyes and cannot selectively attend to one of flashing stimuli using their peripheral vision (covert attention). Tactile-based methods, such as somatosensory stead-state evoked potentials (SSSEP), are a potentially attractive alternative in these scenarios. Attention to tactile stimulation does not require muscle activation in the way visual stimulation does. Here, we compare the neural signals elicited by covert attention to multiple visual stimuli and covert attention to multiple tactile stimuli in naïve BCI users, with the goal of evaluating the feasibility of event potential-based control of an EEG BCI. Although both SSSEP and SSVEP signals could be detected above chance levels, our initial results suggest that the signal-to-noise ratio if SSVEP signals is larger than that obtained using SSSEP.
Keywords: BCI, SSVEP, SSSEP, Attention, EEG