Brains Response to Symbols in Typically Developing Children
Thigpen, Lauren D
Area of Honors:
Communication Sciences and Disorders
Bachelor of Arts
Dr. Krista M Wilkinson, Thesis Supervisor Dr. Ingrid Maria Blood, Honors Advisor
AAC N400 ERP Symbols
Purpose: Individuals who have communicative disorders rely on Augmentative and alternative communication (AAC) to interact with others. Many aided AAC devices use symbol sets as a way to express the English language. The iconic nature of symbols in opposition to the arbitrary nature of words has sparked interest among scientists. This study is designed to measure brainwaves to see if AAC symbols elicit the same response as spoken words.
Methods: Event Related Potentials (ERPs) were recorded and reported for 12 school-aged children. The N400, an index of semantic word processing, and N300, an index of semantic picture processing, were examined when participants were presented with a symbol and spoken word simultaneously.
Results: An increasing N400 effect was found with greatest disparity between congruent and incongruent trials in the 450ms-550ms epoch in the left parietal lobe.
Conclusions: The presence of an N400 indicates that the brain responds to symbols as it does spoken words. The later effect signifies that semantic processing is developmental.