Improving an SSVEP-Based BCI Speller for Pediatric Use

A brain computer interface (BCI) is a novel technology that creates direct communication between brain activity and an external device, such as a computer, to aid people with physical disabilities. Numerous electroencephalographic (EEG) based BCI speller applications have been designed and successfully tested on adults. Yet, few BCI studies have included pediatric users, and no EEG based BCI spellers for children have been reported. BCI speller applications could be useful for children with complex communication disorders to acquire literacy skills, and share their thoughts and feelings without requiring physical movements. In a pilot study, initial use of a developmentally-appropriate speller-storybook interface that relied on steady-state visual evoked potentials (SSVEPs) by two pediatric users with quadriplegic cerebral palsy showed limited speller reliability. The present study seeks to improve this BCI speller-storybook reliability by improving stimulus timing, ease of access, and by adding auditory feedback. Overall, results are expected to improve the reliability of the BCI speller-storybook by increasing selection accuracy, and integrating a multisensory spelling strategy. Preliminary results indicate there is no significant difference in selection time between visual and auditory-visual conditions. Additionally, preliminary results using a video analysis code showed relatively accurate stimulus timing across the 7.5hz, 10hz, and 12hz boxes.  Future work will involve examining the EEG features, including those related to working memory, in relation to the updated speller-storybook interface reliability for pediatric users with complex communication disorders.