Testing the interplay of structure and meaning in aphasic sentence production

Abstract

Background: Improving aphasic sentence production is a challenging endeavour, both for the speaker who must recover the linguistic skill and for the therapist who attempts to guide the process. Studies have demonstrated that treatment can often improve the sentence production ability of aphasic speakers, but with limited generalisation to new lexical content and untrained sentence structure. One factor that limits the outcome of production therapy may be the complexity of the relationship between the form and the meaning of a sentence. This is confounded by a limited array of diagnostic approaches for revealing what linguistic resources remain available to the aphasic speaker.

Aims: In this study we tested a new format for eliciting sentence production in aphasia. Our goal was to reveal whether or not individual aphasic speakers were sensitive to certain semantic and syntactic elements of sentences that are believed to influence the sentence production process.

Methods & Procedures: Using a modified sentence repetition format we explored the sentence production abilities of five fluent aphasic speakers under different conditions of lexical and/or structural manipulations. Lexical manipulations required substitution of a semantically related verb; structural manipulations required reordering of the post‐verbal arguments in different dative constructions (double object and prepositional) that express essentially the same message.

Outcomes & Results: Response patterns obtained from the five aphasic participants revealed individual patterns of skill and sensitivity based on residual language ability. The implications of these results are discussed with reference to the potential for revealing elements of normal production patterns in aphasic speech, and the assumption that such information is important for developing more effective therapy for individuals with aphasia.

Conclusions: Patterns of sentence production elicited in a modified sentence repetition task may reveal syntactic flexibility and residual syntactic knowledge in speakers with aphasia.

Keywords:

• Sentence production
• Verb retrieval
• Aphasia therapy
• Dative alternation
• Syntax.

The preparation of this paper, and the conduct of the research reported here, were supported by grant R01‐DC00262 from the National Institute on Deafness and Other Communication Disorders to the University of Maryland School of Medicine. We wish to thank the control participants in the experiment, and we express our gratitude to the individuals with aphasia who cheerfully supported our research effort with their dedicated participation. This work suppported by the University of Maryland General Clinical Research Center Grant MO1 RR 165000, General Clinical Research Centers Program, National Center for Research Resources (NCRR), NIH.

Notes

1. Phonemic and other cues were used when the speaker appeared unable to overcome a word retrieval block. These cues were used to assess the extent of additional knowledge that was not evident in the initial attempt at a response. Cues were used sparingly, and all data presented were collected before any cue was given.

2. Control data were collected for this and other studies in the same testing sessions. Since the primary purpose of the control testing was to assure that the task would successfully elicit the target structures, we included only a subset of conditions. Type 4 was not tested because it was expected to be the easiest condition (no verb change and production of the prepositional form of the dative).