A quantitative production analysis of picture description

Background: The Quantitative Production Analysis (QPA) (Berndt et al., 2000 Berndt, R. S., Wayland, S., Rochon, E., Saffran, E. and Schwartz, M. 2000. Quantitative production analysis: A training manual for the analysis of aphasic sentence production, Hove, , UK: Psychology Press. [Google Scholar]; Saffran et al., 1989 Saffran, E. M., Berndt, R. S. and Schwartz, M. F. 1989. The quantitative analysis of agrammatic production: Procedure and data.. Brain and Language, 37: 440–479. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) was developed to provide an objective means of characterising the grammaticality of spontaneous speech in aphasia. However, there is still no consensus as to the profile of performance, on this or any other measure, that identifies agrammatism. Aim: The aim of this study is to advance the effort to characterise agrammatic speech production, by examining the influence of aphasia severity and fluency on patterns of QPA scores obtained from a broad range of individuals with aphasia. The goal of this process is to identify the quantitative variables most predictive of agrammatism. Methods & Procedures: Spontaneous speech samples were elicited from non‐brain‐damaged (NBD) older subjects and a group of participants with aphasia unselected by diagnosis, and analysed using the QPA. Data from the NBD and aphasia groups were statistically compared and correlated with ratings of severity. Fluent and non‐fluent subjects within the group with aphasia were then compared. Last, the non‐fluent group was explored for evidence of agrammatism. Outcomes & Results: Many of the QPA's measures were found to reflect the severity of aphasia and/or the fluency of speech production, suggesting that results on these measures may not be indicative of agrammatism per se. In particular, measures of output productivity (the amount and efficiency of production) were largely determined by aphasia severity, and measures of lexical selection were related to the fluency of production. Profiles of the non‐fluent subjects also varied widely, reinforcing the dissociability of different grammatical functions. Conclusions: None of the QPA's measures could be interpreted to reflect agrammatism alone; in fact, many appeared to be reflective of aphasia severity or fluency. Diagnoses of agrammatism still depend on clinical judgement; however, this judgement is aided greatly by the array of objective quantitative information provided by the QPA.