The effect of AAC stimulation on the dorsolateral prefrontal cortex

Open Access
Lichtenwalner, Molly Ada
Area of Honors:
Communication Sciences and Disorders
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Krista M Wilkinson, Thesis Supervisor
  • Ingrid Maria Blood, Honors Advisor
  • AAC
  • dorsolateral
  • prefrontal
  • augmentative
  • communication
This study examined the effect of Augmentative and Alternative Communication on the dorsolateral prefrontal cortex (DLPFC). The question being researched was, “In what ways is the DLPFC involved in AAC display processing and access?” It was hypothesized that different conditions would elicit different levels of DLPFC activation, depending on the memory demands. To test this hypothesis, 18 right-handed adults without disabilities with a mean age range of 20 – 35 took part in this study. Participants were required to take part in a training session where they learned the location of half of the symbols used in the experiment. After the training sessions, participants were screened and asked to enter the fMRI magnet. During this session, DLPFC activation under the two experimental conditions was recorded and analyzed. Results showed that there was equal DLPFC stimulation across both conditions, but both showed higher levels of activation than when no task was being presented. This study was the first of its kind as no previous studies have shown or proved what happens to the DLPFC when it is tasked with using an AAC system. Future research might present participants with more difficult tasks, to determine if task difficulty makes a difference in the success of using or teaching an AAC system.