Lingraphica co-founder and chief scientist, Dr. Richard Steele, summarizes an article from research teams in Pittsburgh on word recognition skills in people with and without aphasia. Read on for the details.
Research teams from the Pittsburgh VA Medical Center and the University of Pittsburgh conducted a study of word recognition skills in persons with and without aphasia. The study evaluated the ability of persons with aphasia—both those with and without hearing loss—to complete a commonly-used word recognition test requiring a verbal response, the Northwestern University Auditory Test No. 6 (NU-6). The goal was to assess the usefulness of such tools for the audiological assessment of persons with aphasia.
Four groups were studied and compared: a) persons with aphasia and normal hearing [n = 25]; b) persons with aphasia and impaired hearing [n = 8]; c) persons with no brain injury and normal hearing [n = 30]; and d) persons with no brain injury but impaired hearing [n = 42]. The assessment task was to repeat words as heard or, where verbal responses were unworkable, to respond by pointing to pictures of named items. Error patterns were assessed to judge also influences of phonotactic probabilities and phonological neighborhood densities.
All participants with no brain injury and most of the participants with aphasia (72.6%) were able to complete the entire assessment. Analysis of responses reveals that the two groups with normal hearing scored significantly higher than the two groups with hearing loss, but that within those groupings, persons without brain injury did not score significantly higher that the persons with aphasia. This suggests that impaired hearing was the dominant factor contributing to erroneous responses on these tasks, the presence or absence of aphasia playing a secondary role. However, in the persons with aphasia, what did appear to influence error rates were the phonological neighborhood densities of test items, though not phonotactic probabilities.
Because a large majority of persons with aphasia were able to complete the assessment, and because the scores of persons with aphasia who completed the assessment did not differ significantly from the scores of persons without aphasia who completed it, the authors conclude that the use of assessment instruments, like the NU-6 for audiological screenings of persons with aphasia, is a workable option, particularly where patients are able to repeat single words. For a minority of persons with brain injury, though, alternative tests may be required.
For further reading: Zhang, M., Pratt, S.R., Doyle, P.J., McNeil, M.R., Durrant, J.D., Roxberg, J., & Ortmann, A. 2017. Audiological Assessment of Word Recognition Skills in Persons with Aphasia. American Journal of Audiology.