Abstracts Computer Science

SSVEP-based BCI performance in children

by Jessica L Mullins

The first contribution of this thesis is to show that children (9-11 years old) can achieve good performance when using a Brain-Computer Interface (BCI) based on the steady-state visually evoked potential (SSVEP). In our study, ten children (mean 9.9 years old) used an SSVEP-based BCI with a mean accuracy rate of 85.6% and a task completion rate of 97.5%. In contrast, a prior study of children (mean 9.8 years old) using an SSVEP-based BCI reported mean accuracy rates of between 50%-76% (depending on stimulation frequency) and a task completion rate of 59%. The second contribution of this thesis is to provide evidence that factors such as motivation or distraction may influence performance by children using SSVEP-based BCI more than the choice of stimulation frequency. Frequencies used by both our study (6-10Hz) and the prior study (7-11Hz) were similar. In contrast, our study asked children to play a computer game in a quiet environment, while the prior study asked children to perform text entry in a noisy environment. The game, which we developed and used for the first time in our study, is ``Brain Storm'  – it allows a single player to pretend to be a farmer protecting crops from malicious lightning clouds using the power of his or her brain. All participants in our study were asked both to complete a target selection task and to play the game. Our results show participants perform better when playing the game (88.6% accuracy rate) than when completing the target selection task (82.5% accuracy rate). Performance in both conditions was better than reported in the prior study (approximately 50% accuracy rate with the 7-11Hz frequency range). Advisors/Committee Members: Bretl, Timothy W. (advisor).