German Language Adaptation of the NAVS (NAVS-G) and of the NAT (NAT-G): Testing Grammar in Aphasia

Abstract

Grammar provides the framework for understanding and producing language. In aphasia, an acquired language disorder, grammatical deficits are diversified and widespread. However, the few assessments for testing grammar in the German language do not consider current linguistic, psycholinguistic, and functional imaging data, which have been shown to be crucial for effective treatment. This study developed German language versions of the Northwestern Assessment of Verbs and Sentences (NAVS-G) and the Northwestern Anagram Test (NAT-G) to examine comprehension and production of verbs, controlling for the number and optionality of verb arguments, and sentences with increasing syntactic complexity. The NAVS-G and NAT-G were tested in 27 healthy participants, 15 right hemispheric stroke patients without aphasia, and 15 stroke patients with mild to residual aphasia. Participants without aphasia showed near-perfect performance, with the exception of (object) relative sentences, where accuracy was associated with educational level. In each patient with aphasia, deficits in more than one subtest were observed. The within and between population-groups logistic mixed regression analyses identified significant impairments in processing syntactic complexity at the verb and sentence levels. These findings indicate that the NAVS-G and NAT-G have potential for testing grammatical competence in (German) stroke patients.

Editorial: New Perspectives and Methodologies in the Diagnosis and Rehabilitation of Aphasia

“…Ditges and colleagues’ article, “German Language Adaptation of the NAVS (NAVS-G) and of the NAT (NAT-G): Testing Grammar in Aphasia” [ 2 ], focuses on the development of the Northwestern Assessment of Verbs and Sentences (NAVS-G) and the Northwestern Anagram Test (NAT-G), two novel and flexible test batteries for testing syntactic complexity (including verb production, processing of simple and complex sentences) in native German-speaking left-hemisphere stroke patients. To investigate the effects of verb argument structure complexity and the canonicity of sentences, NAVS-G and NAT-G were administered to 27 healthy subjects, 15 right-hemispheric stroke patients without aphasia and 15 left-hemispheric stroke patients with mild aphasia; also taken into consideration were the patients’ demographic variables (age and educational level) and stroke-related factors (such as lesion location, size, etiology, and stroke severity).…”