Analyzing Aphasia Diagnoses Through Patterns of Speech Errors and Neuropsychological Tests

Aphasia is an impairment of language, principally affecting the production and/or comprehension of speech. There are many different types, but this study focuses on the four most common ones: Broca’s, Wernicke’s, Anomic, and Conduction. The deficits attributed to aphasia can present themselves in such a wide range of combinations that today’s diagnostic categories seem too inadequate to encompass all possible outcomes. It is expected that a final diagnosis is based solely on the speech production and comprehension deficits presented in a battery of neuropsychological tests. As such, diagnosis of these disorders proves to be a challenging task. This is an archival study that explores the accuracy of the four previously mentioned aphasia diagnoses based on patient performance on a few neuropsychological tests. Using the patterns of speech errors and test scores, discriminate analysis will be used to create a prediction tool in order to see how accurately these scores match aphasia diagnoses. The cognitive psychological literature on decision making leads us to expect that a low percentage of original diagnoses will be correctly classified through the discriminate analysis. These findings would support the notion that these diagnoses do not depend solely on diagnostic tests or that the tests are inadequate on their own. The discussion will explore the reasons for these issues