Sentence comprehension in monolingual and bilingual aphasia: Evidence from behavioral and eye-tracking methods

Aphasia is a language disorder, which is a consequence of acquired brain injury. People with agrammatic aphasia (PWA) have restricted language production, characterized by short and telegraphic sentences. Many PWA have also difficulties understanding some sentences, such as ‘the girl has been chased by the boy’ in English. This sentence is difficult for two reasons. Firstly, it is semantically reversible as ‘boy’ and ‘girl’ can both be the Agent of the action of chasing. Secondly, it is a passive sentence, which does not adhere to the most common word order of the language. It is important to investigate sentence comprehension deficits in PWA speakers of languages that differ in terms of their word order variability.

The current project focuses on sentence comprehension in PWA and unimpaired speakers of a highly inflected and free word order language, (Basque), and/or a less inflected and flexible word order language, (Spanish). It includes a series of studies on bilingual and monolingual speakers in order to consider a) how language-specific properties influence sentence comprehension; b) cross-linguistic transferability of sentence parsing mechanisms in bilingual speakers; c) potential bilingual advantage in sentence comprehension abilities due to enhancement of executive functions, and d) Error awareness in sentence comprehension. It combines behavioral (response accuracy and reaction time) and eye-tracking methods.

The results suggest that a) Word order is a universal characteristic of sentence comprehension deficits in at least some PWA; b) Bilingual speakers do not transfer their abilities to process sentences from the most inflected languages (i.e., Basque) to the less inflected language (i.e., Spanish); c) Bilingual PWA do not show an advantage over monolingual PWA; d) PWA are unaware of their sentence comprehension deficits.