A comparative study of pseudorandom sequences used in a c-VEP based BCI for online wheelchair control.
In this study, a c-VEP based BCI system was developed to run on three distinctive pseudorandom sequences, namely the m-code, the Gold-code, and the Barker-code. The Visual Evoked Potentials (VEPs) were provoked using these codes. In the online session, subjects controlled a LEGO®Mindstorms®robot around a fixed track. Choosing the optimal code proved a significant increase in accuracy (p<;0.00001) over the average performance. No single code proved significantly more accurate than the others (p=0.81), suggesting that the term "optimal code" is subject-dependent. However, the Gold-code was significantly faster than both alternatives (p=0.006, p=0.016). When choosing the optimal code for accuracy, no significant decrease in Time Per Identification (TPI) was found (p=0.67). Thus, when creating an online c-VEP based BCI system, it is recommended to use multiple random sequences for increased performance.
Jonas
J
Isaksen
Ali
A
Mohebbi
Sadasivan
S
Puthusserypady
D062207:Brain-Computer Interfaces; D004569:Electroencephalography; D005074:Evoked Potentials, Visual; D006801:Humans; D010775:Photic Stimulation; D014910:Wheelchairs