A performance-based approach to designing the stimulus presentation paradigm for the P300-based BCI by exploiting coding theory

The P300-based brain-computer interface (BCI) speller relies on eliciting and detecting specific brain responses to target stimulus events, termed event-related potentials (ERPs). In a visual speller, ERPs are elicited when the user's desired character, i.e. the “target,” is flashed on a computer screen. The P300 speller is currently limited by its relatively slow typing speed due to the need for repetitive data measurements that are necessary to achieve reasonable signal-to-noise ratios. In addition, refractory effects limit the ability to elicit ERPs with every target stimulus event presentation. In this paper, we present a new method to design the stimulus presentation paradigm for the P300 speller by exploiting an information-theoretic approach to maximize the information content that is presented to the user while also mitigating refractory effects. We present results with real-time BCI use which demonstrate significant performance improvements with our performance-based paradigm compared to the conventional stimulus presentation paradigm.