From mathematics to language: A novel intervention for sentence comprehension difficulties in aphasia

We report an intervention for severe and chronic sentence comprehension difficulties that used the intact resources of one symbolic system (mathematics) to scaffold impaired capacity in a second symbolic system (language). The study evaluated the outcome of therapy for participant SO. SO retained the ability to understand structural principles such as reversibility in mathematics. The therapy attempted to link this awareness to language expressions in order to enhance his understanding of canonical active sentences. The investigation employed a single case study design, with multiple-baselines. Behaviour was measured prior to intervention, immediately post-intervention, and following an eight week no-therapy maintenance period. A four component therapy programme lasting five weeks was implemented. Untreated control behaviours displayed only minor change following intervention. The intervention resulted in significant and stable improvement in treated behaviours with increased scores for sentence comprehension, including the comprehension of spoken and written reversible sentences. There was generalisation of gains to untreated sentences, and also to sentences which shared the verb, but not the noun phrases of the treated sentences.