Pronoun processing in post-stroke aphasia: a meta-analytic review of individual data

Pronouns constitute a heterogeneous class of linguistic elements, allowing for expression of referential relationships. Pronouns have an important place in daily communication which speakers and listeners rely heavily on for. Aphasia literature has evidenced that pronoun processing is impaired in people with aphasia (PWA), although explanations underpinning pronoun impairments are mixed. To address this, through a systematic literature review, we identified 42 studies which examined pronoun processing (both production and comprehension) in 474 PWA across 16 different languages. An initial meta-analysis was conducted on the overall data with all PWA and pronoun conditions with an outcome measure indicating whether or not pronoun processing is individually impaired in PWA. Further meta-analytic models were built to compare certain conditions of particular interest (e.g. reflexives vs object pronouns, object vs subject wh-pronouns) in an attempt to further disentangle the explanations behind their difficulty in use. Outputs from our meta-analysis suggest that: (i) a form of pronoun impairment is consistently present in aphasia regardless of aphasia type, fluency or language spoken; (ii) pronoun variables show selectivity in their impairment, for instance, reflexives are better preserved over object pronouns, and the subject-advantage in who-pronouns is language-selective; and (iii) other important linguistic variables that largely predict pronoun impairments include aspects like argument position of subject/object phrases, case marking, cliticization, and the presence of relative clause constructions. These outputs are discussed in relation to neurolinguistic hypotheses that predict pronoun impairments in aphasia.