Dr. Krista Wilkinson presented a talk entitled “N400” Brain Responses Are Evoked by Semantic Content in Photographs: Implications for Visual Scene Displays used for Augmentative and Alternative Communication , on April 30, 2012, at the Penn State Social, Life, and Engineering Sciences Imaging Center (SLEIC).
Visual Scene Displays or VSDs are a method of organizing AAC systems by embedding concepts into hotspots within a photograph of a scene. The study Krista discussed employed electroencephalography (EEG) to help better understand whether the brain relates to the linguistic content intended by VSDs as symbolic. The presence of a particular pattern of brainwave activity, called the N400 response, was consistently detected when there was a ‘semantic mismatch’ between the VSD image presented and a message in words paired with it. If both the image and the words matched (conveyed the same message), the N400 response was not present on the EEG. Accordingly, this suggests that VSDs can share the same functions as the types of symbols used traditionally.
This reports on data in a paper currently under review, co-authored by Allyson Stutzman, Andrea Seisler, and Janice Light.