Strong conceptual ability reduces the effect of lexical impairments on verb retrieval in aphasia

Verb-retrieval impairments are pervasive deficits that can negatively impact communicative function for individuals living with aphasia. Unfortunately, the neurocognitive basis of these deficits remains poorly understood. One open question is the degree to which verb-retrieval impairments might be rooted in lexical- versus conceptual-processing deficits. These deficits can be co-present and correlated in people with aphasia, but they have also been found to be dissociated in patients with a variety of acquired brain injuries. This study examined the degree to which conceptual versus lexical action-processing abilities are impaired and may contribute to verb-retrieval impairments in adults with chronic aphasia due to left-hemisphere stroke. The results indicate that conceptual action processing can be impaired in aphasia and may contribute to verb-retrieval impairments. Furthermore, relatively unimpaired conceptual processing can ameliorate the influence of lexical impairments on verb-retrieval impairments. These findings are consistent with models in which conceptual representations play a key role in language processing and may be leveraged to improve verb retrieval in adults with chronic aphasia.