Paper presented at the Science of Aphasia Conference, 2009

Mar 22, '10 7:12 AM for everyone

The comprehension of time reference in agrammatic aphasia: A comparison of languages with Tense and languages with

Aspectual adverbs

Harwintha Y. Anjarningsih, Elif Bamyaci, Chien-Ju Hsu, Roelien Bastiaanse

Center for Language and Cognition Groningen

Introduction

In Indo-European languages, verb inflections specify, among other things, the time-frame in which the event takes place (past, present, future) and both production and comprehension of these verb inflections are difficult for agrammatic speakers. These problems are not restricted to finite verbs as participles are impaired as well. Past verb forms are affected more than present (for Dutch production: Bastiaanse, 2008; Dutch comprehension: Jonkers and de Bruin, in press) and future (for Turkish Yarbay-Duman and Bastiaanse, 2009) verb forms.

The present cross-linguistic study seeks to investigate and compare comprehension of time reference by three groups of speakers with agrammatic aphasia: a Turkish, a Chinese, and an Indonesian group. Of interest is that these three languages have different grammatical systems in expressing time reference. Turkish, a language that uses verb inflections to refer to time (Tense and Aspect), and Chinese and Indonesian, two languages that use aspectual adverbs to refer to past, present, and future. In Turkish, time reference, both Tense and Aspect, is denoted by inflectional suffixes on finite verbs (see example 1).

(1)        adam                            mektup             okuyor            okudu              okuyacak.

            the man                        a letter              [is reading]       read                 [will read]

In Chinese, time reference is denoted by aspectual adverbs. The verbs in Chinese are not inflected (see example 2.)

(2)        zhe ge ren                     zai du               du le    yao du             yi fong sin

            the man                        [is reading]       read     [will read]         a letter

The third language, Indonesian, shows time reference by lexical adverbs (3) or free-standing aspectual adverbs (4). Lexical adverbs are sentential adverbs that in the current study are put at the beginning of sentences. Aspectual adverbs are a part of the Verb Phrase and always come before the verbs that are only inflected for transitivity. Verbs in Indonesian are not inflected for tense, agreement, and mood.

(3) baru saja   sekarang         sebentar lagi               dia        membaca          sebuah surat

     [just now]    now                  [in a moment]               he/she   read                 a letter

(4) laki-laki itu  sudah              sedang                        akan      membaca        sebuah surat

     man   the                  [past]               [present]           [future]  read                a letter 

Aim

The current study compares the comprehension of past, present, and future markers. The questions were:

(1) is comprehension of grammatical time-reference is impaired in agrammatic aphasia?

(2) is time-reference through aspectual adverbs (in Chinese and Indonesian) equally impaired as time-reference through verb inflection (in Turkish)?

(3) there is a difference between reference to past, present, and future as found earlier for production?

(4) is there a difference between comprehension time reference through lexical adverbs and aspectual adverbs (in Indonesian)?

Methods

The comprehension task of the Test for Assessment of Reference of Time (TART: Bastiaanse, Jonkers & Thompson, unpubl.) was used. This test is presently used for 15 languages, including the three languages of this study. Photographs of 20 transitive verbs representing (1) actual performance of the action (present), the completed action (past), and the intention to perform the action (future) were used. The patients were presented with two pictures of the same verb in two time frames and had to match one of them to a spoken sentence. Pictures with targets referring to the past are never presented on the same page with pictures referring to the future because both pictures show “no-action”, which and has been proven to be difficult to differentiate for normal, healthy subjects. For example, the patients were presented with two pictures, the first of which depicts “The man is eating an apple” and the second “The man will eat an apple”. The experimenter asked the patients to point to “The man is eating an apple” and they had to indicate their choice. For Chinese and Turkish, 9 agrammatic patients and 10 healthy control subjects were examined with the test. For Indonesian, data collection is still in progress, therefore we will here only discuss the Chinese and Turkish data.

           

Results

The control subjects scored at ceiling in both languages and their data will be ignored in further analysis. The results of the agrammatic patients are shown in Figure 1.

                                   

Figure 1: Results of the Turkish and Chinese agrammatic patients on the test for comprehension of grammatical time reference (number of correct answers, max. = 20).

T-tests were used to analyse the data. Overall performance of the Turkish and Chinese agrammatic patients on the test was similar (t(16)=-0.074, p=0.94). In both languages, performance on ‘present’ was significantly better than on both ‘past’ (Turkish: t(8)=-2.713; p=0.029; Chinese: t(8)=5.813, p=0.001) and ‘future’ (Turkish: t(8)=3.591, p=0.010; Chinese: t(8)=2.475, p=0.041). ‘Past’ and ‘future’ were not significantly different in both languages, although there is a tendency for past to be more difficult than future in Chinese (Turkish: t(8)=-0.845, p=0.424; Chinese: t(8)=-2.224; p=0.06).

Discussion

The results show that (1) comprehension of grammatical morphemes for time-reference in agrammatic aphasia is impaired; (2) independent on whether this is done through inflection or aspectual adverbs; (3) comprehension of reference to present is better preserved than to past and future. To answer the 4^th research question, the data from Indonesian will be used.

These findings pair with the findings for agrammatic production, that showed that reference to the present is relatively well-preserved. This suggests that there is a central problem in agrammatic aphasia to encode semantic information on time-reference into grammatical morphemes and the other way around, particular information that refers to the past and to the future, at least in comprehension.

If this is indeed what is happening in processing of time reference by agrammatic patients, the same patterns of findings are expected to be found in Indonesian. 

 References

Bastiaanse, R. (2008) Production of verbs in base position by Dutch agrammatic speakers: Inflection versus finiteness. Journal of Neurolinguistics, 21, 104-119.

Jonkers, R. & Bruin, A. de (in press) Tense processing in Broca’s and Wernicke’s aphasia. Aphasiology.

Yarbay Duman, T. & Bastiaanse, R. (2009). Time Reference Through Verb Inflection in Turkish Agrammatic Aphasia. Brain and Language, 108, 30-39.