Lingraphica Co-founder and Chief Scientist, Dr. Richard Steele, summarizes the findings of a study from Cincinnati, OH and Birmingham, AL regarding behavioral and neurophysiological changes in persons with chronic aphasia following training and use of a high-tech AAC device with speech output.
The research had three goals, namely: (i) to study diminution of overall impairment and accompanying improvements in story retelling following intervention, (ii) to explore and characterize changes in accompanying brain activation, and (iii) to compare outcomes in a high-technology intervention group vs. usual care group.
Twelve persons with aphasia (PWA) from a single left cerebrovascular accident (> 12 months) comprised the participant pool, six randomized to the high-technology group and six to a usual care group. For the former, researchers created two personally relevant stories each using visual scene displays on a DynaVox Vmax™; for the usual-care group, participants received treatment based on Schuell’s stimulation approach. Intervention occupied 12 clinical hours over four weeks. Outcome data were gathered from: (i) administration of standardized assessments instruments; (ii) taping of stories being retold, for discourse analysis, and (iii) for f-MRI analysis, data capture from participants in scanners who were shown a noun and asked to produce an associated verb in thought (covert), to produce an associated verb in speech (overt), and to say the name of the noun aloud.
Both the high-technology group and usual care group showed improvements following intervention, but group comparisons showed the former trended towards greater effect size in standardized assessments and higher activity counts in discourse analysis of their story retelling. In both groups, analysis of fMRI activation patterns revealed a trend towards increased left hemisphere activity lateralization during the language-engaging activities, while cortical areas associated with visual processing appeared to show increased engagement in the high-technology AAC group.
The work complements existing research into outcome benefits from AAC intervention in chronic aphasia by characterizing discourse changes and cerebral activation patterns that accompany improvements in standardized assessments. The findings extend perspectives and suggest topics for future research.
For further reading: A. Dietz, J. Vannest, T. Maloney, M. Altaye, S. Holland & J. P. Szaflarski, 2018. The feasibility of improving discourse in people with aphasia through AAC: clinical and functional MRI correlates. Aphasiology.