title: Does bimodal stimulus presentation increase ERP components usable in BCIs?
abstract: Event-related potential (ERP)-based brain-computer interfaces (BCIs) employ differences in brain responses to attended and ignored stimuli. Typically, visual stimuli are used. Tactile stimuli have recently been suggested as a gaze-independent alternative. Bimodal stimuli could evoke additional brain activity due to multisensory integration which may be of use in BCIs. We investigated the effect of visual-tactile stimulus presentation on the chain of ERP components, BCI performance (classification accuracies and bitrates) and participants' task performance (counting of targets). Ten participants were instructed to navigate a visual display by attending (spatially) to targets in sequences of either visual, tactile or visual-tactile stimuli. We observe that attending to visual-tactile (compared to either visual or tactile) stimuli results in an enhanced early ERP component (N1). This bimodal N1 may enhance BCI performance, as suggested by a nonsignificant positive trend in offline classification accuracies. A late ERP component (P300) is reduced when attending to visual-tactile compared to visual stimuli, which is consistent with the nonsignificant negative trend of participants' task performance. We discuss these findings in the light of affected spatial attention at high-level compared to low-level stimulus processing. Furthermore, we evaluate bimodal BCIs from a practical perspective and for future applications.
authors: TNO, PO Box 23, 3769DE Soesterberg, the Netherlands. Utrecht University, Utrecht, the Netherlands. M.E.Thurlings@uu.nl
authors: Marieke E
authors: ME
authors: Thurlings
authors: Anne-Marie
authors: AM
authors: Brouwer
authors: Jan B F
authors: JB
authors: Van Erp
authors: Benjamin
authors: B
authors: Blankertz
authors: Peter J
authors: PJ
authors: Werkhoven
mesh_terms: D000328:Adult; D062207:Brain-Computer Interfaces; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods*; D011597:Psychomotor Performance / Q000502:physiology*; D014110:Touch / Q000502:physiology*; D055815:Young Adult