Аннотация:In Farwell-Donchin (P300) BCI, attention acts as a factor mediating operator's control over a computer. However, attention can be captured by various distractors. In
some context, a command may be unwanted or even dangerous (e.g., deleting an important file). Is it easy for a user to prevent triggering such commands occasionally?
Moreover, can the expected loss associated with a command make it act as an emotional distractor, so that the attention will preferably trigger this command? 11 normal
subjects were trained to use BCI (3x3 matrix with simple pictorial symbols) with ~0.7-0.8 accuracy, and then played a game: correct "entering" the target symbol gave one
point; entering the symbol which was the previous trial's target (PTT, or "dangerous symbol") led to 5 point loss in "dangerous" condition (DC, 21-42 trials) but did not
change the score in control condition (CC, same n of trials); other errors did not change the score. In each trial the target position was adjacent to the target position of the
previous trial. All but one subject at least once entered a PTT in the DC. Mean number of entering PTT was 2.0 in DC and 1.1 in CC; the difference was not significant
(p=0.16). Among the cases of high number of PTT in DC were a student who had an exam 15 min after the experiment, and a person who felt herself especially nervous
during a block where she made all such errors. Though we cannot be certain yet that harmful commands may indeed be activated preferably, it is clear that blocking their
random activation may be not a simple task for a BCI user.