ERP Based Communication Device for Nonverbal Children on the Autism Spectrum 

Children with Autism Spectrum Disorders (ASD) exhibit varying levels of communication abilities. In this project, the investigator addressed the communication needs of the subset that: 1) lack expressive speech and language; 2) lack ability to operate a keyboard, pointing device, or other typical assistive interface; and 3) are assumed to have adequate cognition, literacy, and receptive language understanding. This research aimed to develop a communication system for such children. Resulting technology could benefit other children and adults with adequate cognition but limited communication options. The investigator developed an assistive communication facilitation device referred to as the RSVP Keyboard. It unites three technologies: 1) Rapid serial visual presentation (RSVP, with individually adjustable presentation rates) of letters/words/phrases; 2) a yes/no intent detection mechanism based on detecting evoked-response potentials (ERP) in the brain to determine which target letter or letters the child wants to convey; 3) a statistical language model based dynamic sequencing optimization procedure that computes which letter needs to be presented next to take advantage of regularities in language. The system operated by showing the sequence of candidate letters on the screen as well as previously typed text, such that words and phrases are formed naturally by adding selected letters. The first goal was to test the viability of the basic concept of facilitated communication through the RSVP Keyboard System. Upon demonstration of feasibility through neuroimaging and statistical analysis of brain responses to RSVP stimuli sequences, the investigator evaluated performances of typically developing children and nonverbal children with ASD in three interactive cognitive tasks.