Speaking in ellipses: The effect of a compensatory style of speech on functional communication in chronic agrammatism

Abstract

This study investigated whether a Dutch and adapted version of Reduced Syntax Therapy (REST) could stimulate and automatise the production of ellipses in Dutch-speaking, chronically agrammatic speakers (N = 12). Ellipses are syntactic frames in which slots for grammatical morphology tend to be lacking (e.g., everybody inside). When elliptical style is applied on a regular basis, the linguistic impairment is circumvented, at least for the greater part. We therefore hypothesised that REST increases participants’ functional communication skills (i.e., communicative efficacy and efficiency). This is of relevance because not all chronically agrammatic speakers become skilled at employing ellipses independently. The results of the present study suggested that when elliptical style is applied regularly, chronically agrammatic speakers get their message across more efficiently when compared to error-strewn production of sentential style.

Keywords:

• Agrammatic speech
• Compensation therapy
• Speaking in ellipses
• Functional communication
• Between-subject variability.

We thank Walter Huber, Francesca Longoni, and Paul Conroy for their valuable and constructive comments on an earlier version of this paper. We would also like to thank Luise Springer and colleagues for allowing us to use the label Reduced Syntax Therapy in evaluating a Dutch and adapted version of this approach.

The study described in this article was supported by the rehabilitation centre of the Sint Maartenskliniek in Nijmegen and conducted in collaboration with the Donders Centre for Cognition as well as the Department of Linguistics of the Radboud University Nijmegen.

Notes

¹Springer et al. (2000) take the bilaterally represented protolanguage as a basis for explaining agrammatic symptoms, which consists of sequencing content words. Due to brain damage, the left hemispheric inhibition of the right hemisphere decreases. Consequently, right hemispheric protolanguage mechanisms may become operative again. This typically occurs only in the chronic phase. In arguing against this claim of Springer et al., Kolk (2002) raises two issues. First of all, the REST constructions are not only produced by chronically agrammatic speakers but also by healthy adults. This empirically refutes the claim that the left hemisphere inhibits the right hemispheric production of such constructions. What is more, even if the protolanguage theory could account for the occurrence of spontaneous recovery, it cannot explain “guided” recovery (i.e., recovery that is increased as the result of training, see Robertson & Murre, 1999). Treatment, especially if it aims at restoration, will strengthen the left hemispheric language functions rather than diminish it. Thus, restoration therapy should inhibit rather than facilitate right hemispheric protolanguage mechanisms.

²Five out of the 10 levels of the Dutch and adapted version of REST (Ruiter et al., 2003) train subject-predicate connections. Compared to isolated predicates, subject-predicate connections may be more difficult to produce, because the subject and predicate are not integrated in a single syntactic frame (De Roo, 1999). A subject NP is frequently added in producing the isolated predicate for a second time (e.g., “drinking coffee woman drinking coffee”). The fact that subject-predicates are more difficult to produce, may explain why they occur only infrequently in agrammatic speech. These connections are trained in REST because they allow speakers to express their messages less ambiguously.

³We do not claim that ellipses can be understood as easily as correctly and fluently produced sentences. From the listener's point of view, ellipses require more inferential work to compensate for the omitted elements. In discussing the effect of elliptical style on communication, we compare preventive to non-preventive style.

⁴In the study of Van den Berg and Kolk (1996), the two participants significantly increased the percentage of ellipses produced after a therapy that was very similar to REST. An increase of 16.3% caused the A-scale score of the Amsterdam-Nijmegen Everyday Language Test (ANELT; Blomert et al., 1995) to increase with 16 points. An increase of at least 7 points on this scale indicates a reliable change in verbal communication skill (Blomert, 1994). Since the data obtained by Van den Berg and Kolk indicated a clinically relevant increase in communicative efficacy, we estimated the effect size at 20%.

⁵The implicit assumption underlying the definition of the style of speech continuum is that every agrammatic speaker who does not demonstrate paragrammatism or non-fluencies is a preventive speaker, who employs elliptical constructions predominantly. As Table 2 demonstrates, to a large extent this is true. However, there is also a small percent of correct sentences. The large majority of these sentences, however, were simple sentences, and could therefore still be seen as the consequence of preventive adaptation. This is indicated by the observation that only 4 of the 17 fluent and full sentences that were produced by a few of our participants contained a subordinate clause.

⁶One reviewer remarked that the style of speech continuum cannot be considered a true continuum since 10 of the 12 participants (all except TW and WR) show outstandingly high values for corrective style of speech. However it is to be noted that the variation in the group as a whole was large enough to bring about significant correlations. Without TW and WR, the significance of these correlations did not change for the greater part. That is, with N = 10, all correlations between the style of speech continuum and the primary outcomes measures as well as the neuropsychological measures remained significant. The only exception is the correlation between the AESQ and the style of speech continuum, which failed to reach significance with N = 8 (ML and HK had missing data for the AESQ), r = −.083, p > .05. These correlations confirm our assumption that there is truly a continuum that underlies the stylistic differences within our group of agrammatic patients.

⁷Since two of the 12 participants (i.e., GJ and EL) were unable to complete the Stroop test and none of the remaining 10 participants produced response times that came within the range of healthy controls, the interference effect could not be established from the norm data of Schmand, Houx, and De Koning (2002).

⁸At T1, T2 as well as T3, all participants (N = 12) produced sufficient sample sizes in the HF and across conditions. Thus, these samples yielded reliable measures of language performance. However, since not all participants produced sufficient sample sizes in the AAT and PDT, the results obtained in these conditions have to be interpreted with caution (for details, see Ruiter, 2008).

To give an indication of the percentage of material excluded from analysis, we provide for each participant the percentage of clauses excluded across conditions (i.e., AAT, PDT, and HF) and across points in time at which the effect of REST was assessed (i.e., pre, post, and follow-up): GJ: 33.23%, EL: 13.46%, CP: 6.20%, AJ: 7.30%, ML: 10.48%, HK: 8.93%, RK: 12.35%, JP: 5.99%, PO: 28.55%, AH: 12.04%, TW: 14.15%, and WR: 14.12%. The weighted mean was 18.07%.

⁹Participants were also presented with the Amsterdam-Nijmegen Everyday Language Test (ANELT; Blomert, Koster, & Kean, 1995). However, the test scores could not be used due to an experimental error.

¹⁰There were no non-compliant participants. Secondly, we recall that none of the 12 participants produced significantly more well-formed sentences in the SOIT (all p values >.05). Thus, spontaneous recovery cannot explain possible improvements after therapy.

¹¹As indicated before, we do not make a categorical distinction between preventive and non-preventive speakers. Instead, we opt for a continuum. For reasons of convenience, however, we will use these labels as an alternative for the more preventive and the more non-preventive speakers.

¹²Correlating the neuropsychological factors with the outcome measures of grammatical output across conditions at T2 yielded the same trends. That is, the more agrammatic speakers accept ellipses and the more they are aware of their language difficulties, the larger the effect of REST on their grammatical output. Also in line with our predictions, the effects on grammatical output were larger in participants with good executive functioning. However, none of the correlations were significant, all p values >.05.