Date of Award

2015-01-01

Degree Name

Master of Science

Department

Speech-Language Pathology

Advisor(s)

Patricia Lara

Abstract

The aim of this study is to investigate whether deficits in processing affect auditory and reading comprehension in the same manner. This study compared the behavioral and electrophysiologic performance of four individuals with aphasia and four participants with no brain damage responding to spoken and written sentence length commands using a modified version of the Revised Token Test (McNeil & Prescott, 1978). Electrophysiological responses were recorded from the scalp using event related potentials (ERP). The latency and amplitude of the N400 ERP component were measured and analyzed. Behavioral reaction times and correct responses were collected and examined. Performance differences between the two groups were compared, as were differences between the auditory and reading tasks within groups. Results show that participants with aphasia displayed a statistically significant difference in behavioral reaction times, displaying longer behavioral reaction times than persons with no brain damage. In addition, the participants with aphasia also demonstrated significantly longer behavioral reaction times responding to written sentence length commands than spoken sentence length commands. However, the individuals with no brain damage demonstrated behavioral performance patterns similar to those demonstrated by the individuals with aphasia. No statistically significant difference was found between the two groups for correct response rate, latency and amplitude of the N400 ERP component. The cortical activation patterns between the two groups differed for spoken sentence length commands but not for written spoken length commands. The individuals with no brain damage displayed similar localized activation in the frontal-central electrodes when responding to both spoken and written sentence length commands, while individuals with aphasia displayed highly dispersed pattern activation for the spoken sentence length commands. Notably, previous studies on individuals with no brain damage have reported similar findings to the ones observed in the individuals with aphasia in the current study. The results of this study suggest that sentence comprehension impairments in individuals with aphasia do not appear to be modality specific.

Language

en

Provenance

Received from ProQuest

File Size

75 pages

File Format

application/pdf

Rights Holder

Sha-Renae Alexander

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