A "Core Skills" Approach to the Assessment of Acquired Language Disorders: Exploration and Cross-Validation

The majority of diagnostic assessments of aphasia—an acquired language disorder that commonly occurs after stroke or brain injury—are based upon the classical model of language. A major limitation of these diagnostic assessments is that they are based upon a very simple neuroanatomical model of language function. In the decades since the classical model, cognitive theories of language function have developed considerably, which provides a much richer framework for the assessment of acquired language disorders. On the basis of this framework, Faulkner, Wilshire, Parker, and Cunningham (2015) developed the Brief Language Assessment for Surgical Tumours (BLAST) for the assessment of language function in brain tumour patients, based upon the notion that language can be decomposed into core cognitive skills. In the current thesis, we evaluate the efficacy of the BLAST in individuals with chronic post-stroke aphasia, cross-validate the core cognitive skills identified by the BLAST with independent measures argued to index the same theoretical construct, and evaluate whether an individual’s linguistic profile on the BLAST is predictive of performance on a more naturalistic sentence production task. The results from the current research can be divided into three primary findings. First, we found that the BLAST could be administered to individuals with post-stroke aphasia, and that the linguistic profiles provided by the BLAST extend far beyond the predictions derived from neural localization and classical diagnostic assessments. Second, we found support for the validity of five of the core cognitive skills. Third, we found some support for the notion that performance on the BLAST may be predictive of performance on a more naturalistic sentence production task. In short, the current findings suggest that the BLAST holds potential as a clinical tool for the assessment of language function in a range of different neurological populations.