Investigating language processing in stroke-affected brains: a pilot study on the key role of stimulus design to capture interface domains

Stroke represents one of the leading causes of acquired cognitive and communicative impairments, limiting the ability to use language appropriately and profoundly impacting quality of life and social participation. Post-stroke aphasia offers a crucial pathway for the understanding of the neuropsychological correlates of language processing and, despite advances in acute stroke management, linguistic deficits continue to represent a significant challenge for rehabilitation and long-term care. Additionally, one of the major challenges in investigating post-stroke language deficits lies in the marked variability across patients. In this pilot study, we investigated whether stimulus design may enhance the detection of linguistic processing deficits in stroke-affected individuals, targeting lexical class distinctions and morphosyntax/lexical semantics interface-level processing. Results from twelve Italian-speaking patients with unilateral stroke (6 left-hemisphere, 6 right-hemisphere) revealed differential effects of lesion lateralisation and lexical class on task performance. Task accuracy was shaped by individual and lesion-related factors, revealing task-specific dissociations between left- and right-hemisphere patients. These findings underscore the value of using targeted linguistic stimuli to detect subtle deficits that may go undetected by standard screening tools, contributing to a more comprehensive understanding of post-stroke aphasia.