Syntactic cueing of spoken naming in jargon aphasia

Background: Debate surrounds the relationships between the systems involved in spoken word production, the activation governing production, and the role of syntax in production. Jargon aphasia provides an opportunity to investigate the relationship between syntax and phonology as it often involves retained syntax, alongside phonological deficits shown through neologistic output. Models of spoken word production differ in terms of their accounts of the processing relationships between these two levels of representation, and the degree to which syntax is activated and affects phonology.

Aims: We aimed to complete a single case study investigation of the impact of syntactic cues on spoken word production, and to compare data from this implicit task with data from an explicit syntax judgement task. The investigation aims to shed light on different theories of spoken word production, provide new evidence concerning the nature of the deficit in jargon aphasia, and identify potential intervention methods.

Methods & Procedures: The participant DP presented with transcortical sensory aphasia, with fluent neologistic output, a comprehension deficit, anomia, and preserved repetition. The investigations into DP’s noun syntax processing included syntactic cueing of naming, and a syntactic judgement task. The cueing task compared cued and uncued naming, where cues provided syntactic information relevant to count or mass noun targets. The judgement task investigated DP’s knowledge of potential determiner plus noun combinations.

Outcomes and results: Syntactic cues led to increased overall naming accuracy, increased numbers of nouns, more phonologically related errors, and fewer unrelated word errors. The cues had no effect on the proportion of lexical versus non-lexical responses, nor on rates of semantic errors. In contrast to the positive impact of cues, DP showed limited knowledge of the meanings of determiners via the explicit judgement task.

Conclusions: The evidence supports a spoken word production theory that has feedforward only activation from the syntactic to the semantic level, but allows interaction between syntactic and phonological representations. This account explains the lack of semantic errors, and the increase in phonologically related errors in the cued condition. DP’s difficulties completing the explicit judgement task provide more evidence of the need for online tasks which address language processing directly. New evidence of positive effects of syntactic cues on word retrieval informs future interventions for speakers with jargon aphasia.