The sentence production test for aphasia

Abstract

Background: Researchers and clinicians have long known that in aphasia, the ability to produce connected speech is poorly predicted by tests of single-word production. Connected speech is most commonly assessed using rating scales, in which the examiner rates the speech on various fluency-related and grammatical well-formedness measures. However, with this method, interrater and test–retest reliability can be poor, and since the intended utterance is not known, accuracy and appropriate of the speech content is difficult to measure.

Aims: The aim of the present study was to develop and investigate the validity and usefulness of a new, freely accessible sentence production test (SPT) based on simple pictured event description.

Methods & Procedures: The SPT involves describing simple pictured events. The test pictures represent a range of sentence constructions and lexical items, which elicited high response agreement in healthy controls. The simple automatised scoring procedure generates both general and specific accuracy measures. This article describes the test construction and norming procedure and reports test data from 24 participants with aphasia.

Outcomes & Results: Interrater reliability for the scoring protocol was excellent. The overall sentence score was found to measure unique variance not accounted for by single-picture naming. It was unrelated to fluency measures such as speech rate. Specific scores, such as the closed-class score, measure partially overlapping, but qualitatively distinct constructs from other speech assessments.

Conclusions: The SPT is quick to administer, easy to score and can be used even when a person’s speech is very limited. It provides a range of measures of sentence production that may prove informative for both clinical and research purposes.

Keywords:

• Aphasia
• Sentence production
• Assessment

The authors would like to thank Richard Moore for creating the beautiful pictures used in our test materials (for further information, see http://www.artbyrichardmoore.com). Thanks also to Dr Nadine Martin from the Temple University School of Speech and Hearing Sciences, for allowing us to include test data for participants FS, XX, DD, EC and TB. Thanks also to Alana Oakly for her help with the interrater reliability analysis. Finally, we are grateful for all those who helped to collect test data for us, particularly Christina Cameron Jones and Corinne Bareham, who tested and transcribed data for many participants on our behalf. The first and third authors were supported in part during this work by a grant from the Marsden fund of New Zealand [VUW0505; C Wilshire Principal Investigator]. The second author’s work was supported by a Victoria University of Wellington PhD Scholarship (2002–2005) and a Victoria University Doctoral Completion Scholarship (2005–2006).

Notes

¹ A further five pictures were included in the original test to elicit subject–object relative sentences. These were subsequently excluded from the analysis, as they failed to reliably elicit the target construction.

² The six pictures depicting prepositional constructions (e.g., The mouse is under the pumpkin) elicited relatively high response agreement during our initial norming procedure. However, the decision was made not to include these items in the final test, because they yielded extremely low response agreement in a pilot study involving a number of participants with aphasia.

³ Patient NW, who correctly produced only 21% of all scoreable elements, was excluded from this analysis.