Effects of Feedback Latency on P300-based Brain-computer Interface
This addresses a gap in understanding feedback effects for P300-based BCIs, which could improve usability for users with motor impairments, though it is incremental as it builds on prior BCI research.
The study investigated whether feedback improves performance in P300-based brain-computer interface (BCI) spelling tasks, finding that feedback significantly enhanced performance when provided in short intervals (e.g., 4-6 flashes per row/column) and increased discrimination between target and nontarget EEG patterns.
Feedback has been shown to affect performance when using a Brain-Computer Interface (BCI) based on sensorimotor rhythms. In contrast, little is known about the influence of feedback on P300-based BCIs. There is still an open question whether feedback affects the regulation of P300 and consequently the operation of P300-based BCIs. In this paper, for the first time, the influence of feedback on the P300-based BCI speller task is systematically assessed. For this purpose, 24 healthy participants performed the classic P300-based BCI speller task, while only half of them received feedback. Importantly, the number of flashes per letter was reduced on a regular basis in order to increase the frequency of providing feedback. Experimental results showed that feedback could significantly improve the P300-based BCI speller performance, if it was provided in short time intervals (e.g. in sequences as short as 4 to 6 flashes per row/column). Moreover, our offline analysis showed that providing feedback remarkably enhanced the relevant ERP patterns and attenuated the irrelevant ERP patterns, such that the discrimination between target and nontarget EEG trials increased.