Deciphering the mechanisms of phonological therapy in jargon aphasia

Background: Severe word production difficulties remain one of the most challenging clinical symptoms to treat in individuals with jargon aphasia. Clinically, it is important to determine why some individuals with jargon aphasia improve following therapy when others do not. We report a therapy study with AM, an individual with severe neologistic jargon aphasia, and provide a subsequent comparison to previous cases, with the purpose of informing both our theoretical and clinical understanding of jargon aphasia. Aims: This research aimed to investigate AM’s locus of word production deficit and determine the effectiveness of Phonological Component Analysis (PCA) therapy, a phonological cueing therapy, in the re-learning and generalization of naming responses for words. In addition, AM’s performance in therapy, linguistic profile, and ability to engage with therapy/cues were compared in a retrospective analysis with the background linguistic and therapy data of two other individuals with jargon aphasia (P9, Leonard et al., 2008; FF, Bose, 2013), who responded differentially to PCA. This was undertake to explore possible prognostic indicators of phonological therapy for jargon aphasia. Methods and Procedures: A battery of linguistic and neuropsychological tests was used to identify AM’s word production deficit. A single-subject multiple probe design across behaviours was employed to evaluate the effects of PCA therapy on the re-learning and generalization of naming responses. In the retrospective analysis of AM, P9 and FF, we compared differences and similarities in performance on various linguistic tasks, the ability to engage in therapy (i.e., ability to generate and utilize the cues), as well as to retain and maintain cues. Outcomes and Results: AM’s locus of deficit was identified in the mapping between semantics and phonology. PCA was found to be effective in improving naming in two of the three treated word lists during the treatment phase; however, these gains were not maintained. Generalization to untreated picture names was not observed. Findings from the retrospective analysis illustrated that oral reading skills, ability to segment phonological information from words and active engagement with provided cues are likely prerequisites for obtaining robust and long-term gains. Conclusions and Implications: We demonstrated that phonological therapy could be beneficial for the remediation of naming abilities at least in the re-learning phase; however, maintenance and generalization of these gains were limited. This research helps to elucidate the considerations and evaluations necessary for the appropriateness of phonological therapy and candidacy of individuals with jargon aphasia for this treatment approach