[Dependence N200 and P300 ERPs in P300-based brain-computer interface on the variations of voluntary attention]

Hypothesis about dependence P300 and N200 potentials evoked by flashes of rows and columns of the stimulation matrix on type of the task and voluntary attention was evaluated. We tested three types of the task: 1) just look at target symbol; 2) look at the target symbol, count its flashes and report the amount of flashes after finishing the task; 3) type target symbol in P300-based brain-computer interface (BCI). In 17 subjects research we showed that maximum amplitudes of P300 and N200 ERPs was occurred in the second type of the task ("look at and count flashes"). Also in this type of task we observed most of all cases statistically reliable difference between target and nontarget P300 and N200 ERPs. Lowest amplitudes of ERPs and number of cases of statistically reliable differences between target and nontarget were showed in the first type of the task ("just look at the symbol"). So we assume that succesful working in P300-based BCI doesn't need the maximum amplitudes of the relevent ERPs but most depend on spatiotemporal complex of these potentials.