Phonological cueing of word finding in aphasia: Insights from simulations of immediate and treatment effects

Background: Difficulties with word finding occasionally occur in all speakers and commonly in all aphasia types. An understanding of these difficulties and their treatment-induced improvement is of fundamental scientific and clinical importance. Phonological cueing yields immediate and treatment effects in behavioural and neural measures. Disagreement exists about the locus of the cueing effects in aphasia and whether the effects arise from the same neurocognitive mechanisms as phonological effects in picture naming by healthy speakers. Aims: Computer simulations were conducted to expand our understanding of immediate and treatment effects on word finding in behavioural and neural measures and to examine whether a unified account of the phonological effects in health and disease is possible. Methods & Procedure: Picture naming performance of the WEAVER computer model, which accounts for immediate phonological effects in healthy speakers, was assessed in simulations of immediate and treatment effects of phonological cueing in poststroke aphasia. The model assumes (1) a phonological encoding locus of the cueing effects, (2) a cohort mechanism in cue perception, and (3) activation of lexical and sublexical phonological levels by the cues. Outcomes & Results: The model successfully simulated the empirically observed effects in behavioural naming performance and neural measures. Conclusions: The simulations provide a proof of concept for the idea that immediate and treatment effects of phonological cueing in aphasia arise from the same neurocognitive mechanisms as immediate phonological effects in healthy speakers. This expands our understanding of word finding, associated difficulties, and their improvement by therapy