Communicative performance in aphasia — the effect of syntactic processing skills

Abstract

ABSTRACT There has been much debate as to the nature of the relationship between language processing skills and communicative success in aphasia (see, for example, Hermann et al., 1989, Feyereisen, 1991). This paper reports a preliminary analysis of data from a wider project which aims to explore this relationship. The study has been designed to compare language processing abilities with an overall measure of aphasia serverity (from the Boston Diagnostic Aphasia Examination (Goodglass & Kaplan, 1983) and performance on a collaborative communication task, the ‘Map Task’ (Brown et al. 1984) which allows the quantification of communicative skills. Data will be presented from a subset of eight subjects involved in the wider study (N=16). These individuals (aged between 31–71 years) all became aphasic following cerebrovascular accident (CVA) between 3–13 years ago. The focus of this paper will be the relationship of sentence processing skills with communicative competence. Discussion of the data from subject BA will examine differences between an individual's syntactic potential (structures gathered via elicitation) and those structures deployed through choice in a particular situation. The sentence processing potential of the eight subjects reported here was assessed by use of the South Tyneside Assessment of Syntactic Structure (STASS) (Armstrong & Ainley, 1991). The ‘Map Task’ (Brown et al., 1984) provided a measure of communicative success. Contrary to the conclusions of previous studies (for example, Penn, 1988) analysis of the group data suggests that communicative competence is related to syntactic processing skills. Subjects able to manipulate three‐ and four‐element causal structures seemed to achieve greater communicative success on the ‘Map Task’ (Brown et al., 1984). However, there was wide inter‐subject variation. This will be illustrated by data from one subject, BA, whose syntactic output on the ‘Map Task’ was analysed by use of the Language Assessment Remediation and Screening Procedure (LARSP) (Crystal, Fletcher & Garman, 1976). The elicited syntax of BA revealed a reliance on single‐ and two‐element clause structures, but communicative competence was good. Analysis of syntax from the ‘Map Task’ (Brown et al., 1984) dialogue revealed expansion of one‐/two‐element clauses to three‐ or four‐element clauses via the use of ‘chains’ of adverbials. Examples of these include conversational ‘padding’, such as ‘actually’, ‘maybe’ and directional instructions, such as ‘here’, ‘north’ and ‘back’. Analysis also revealed use of prosody to establish links between elements. The accuracy BA displayed in conveying directions and distances was also found to be very important to his communicative competence on this task. Thus, although group results indicate that relatively spared syntax is indicative of communicative success, individual case study material points also to the importance of the interaction of syntax with other levels of linguistic processing. Subject BA illustrates how retained lexical and discourse skills can compensate for severe syntactic impairment to achieve communicative success.