Boston Diagnostic Aphasia Examination
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The Boston Diagnostic Aphasia Examination or BDAE is a neuropsychological battery used to evaluate adults suspected of having aphasia, and is currently in its third edition. It was created by Harold Goodglass and Edith Kaplan. The BDAE evaluates language skills based on perceptual modalities (auditory, visual, and gestural), processing functions (comprehension, analysis, problem-solving), and response modalities (writing, articulation, and manipulation). Administration time ranges from 35 to 45 minutes. Many other tests are sometimes used by neurologists and speech language pathologists on a case-by-case basis, and other comprehensive tests exist like the Western Aphasia Battery.
The Boston Diagnostic Aphasia Examination is a comprehensive, multifactorial battery designed to evaluate a broad range of language impairments that often arise as a consequence of organic brain dysfunction. The Examination is designed to go beyond simple functional definitions of aphasia into the components of language dysfunctions (symptoms) that have been shown to underlie the various aphasic syndromes. Thus, this test evaluates various perceptual modalities (e.g., auditory, visual, and gestural), processing functions (e.g., comprehension, analysis, problem-solving), and response modalities (e.g., writing, articulation, and manipulation). This approach allows for the neuropsychological analysis and measurement of language-related skills and abilities from both ideographic and nomothetic bases, as well as a comprehensive approach to the symptom configurations that relate to neuropathologic conditions.
The manual provides clear statements and rules for scoring protocols.
Reliability of the subtests was studied by selecting protocols of 34 patients with a degree of severity of aphasia ranging from slight to severe. Kuder-Richardson reliability coefficients for subtests ranged from .68 to .98, with about two-thirds of the coefficients reported ranging from .90 upwards. Since test-retest reliability is difficult if not impossible to attain with patients suffering from aphasic symptoms, the current reliability coefficients demonstrate very good internal consistency in terms of what the items within the subtests are measuring.
Validity: A discriminant analysis comparing "unambiguous exemplars of a single syndrome" was carried out. Thus, unambiguous cases of Broca’s aphasia, Wernicke’s aphasia, conduction aphasia, and anomic aphasia were selected. Ten variables were selected on the assumption of providing the most useful data. From these, five variables were selected for the discriminant analysis (body part identification, repetition of high probability sentences, verbal paraphasias, articulatory agility rating, and automated sentence rating). This classification yielded no misclassifications.
Standardization of the revised Boston Diagnostic Aphasia Examination is based on a normative sample of 242 patients with aphasic symptoms tested at the Boston VA Medical Center between 1976-1982. It is important to consider that this sample includes only male, presumably English-speaking patients and is thus highly selected.
- Lezak, Muriel D.; Howieson, Diane B.; Bigler, Erin D.; Tranel, Daniel (2012). Neuropsychological Assessment (Fifth ed.). Oxford: Oxford University Press. ISBN 978-0-19-539552-5. Retrieved 17 June 2014. Lay summary – Journal of the International Neuropsychological Society (17 June 2014).
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