RP-Department of Special Needs Education

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Browsing RP-Department of Special Needs Education by Author "Bastiaanse, Roelien"

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    Production and Comprehension of Reference of Time in Swahili–English Bilingual Agrammatic Speakers
    (Routlage, 2012-07-24) Abuom, Tom O; Bastiaanse, Roelien
    Background: Several studies on time reference show that monolingual agrammatic speakers have difficulty producing and/or comprehending verb forms referring to past events or actions. The PAst Discourse LInking Hypothesis (PADILIH) has been formulated to account for this phenomenon (Bastiaanse et al., 2011). In the current study on bilingual aphasia we examine whether time reference problems, especially reference to the past, extend to both languages of bilinguals with agrammatic aphasia. The two languages, Swahili and English, have different verb morphology for expressing reference of time. Aims: The current study tested the production and comprehension of reference of time through verb morphology in two languages of Swahili–English bilingual agrammatic speakers. Methods & Procedures: A total of 13 agrammatic speakers and 13 non-brain-damaged individuals were tested using an adaptation of the Test for Assessing Reference of Time (TART; Bastiaanse, Jonkers, & Thompson, 2008; Swahili version: Abuom & Bastiaanse, 2010). Reference to the past, present, and future conditions were examined through a sentence-completion and a picture–sentence-matching task. Outcomes & Results: While the non-brain-damaged participants performed at ceiling in both languages, the agrammatic individuals’ performance showed a selective deficit of reference to the past on both comprehension and production tasks. A similar pattern was observed in the two languages in spite of the structural differences. Conclusions: The PAst Discourse LInking Hypothesis (PADILIH) was supported by these results. Furthermore it has been revealed that time reference deficits extend to both tested languages of bilingual speakers with agrammatic aphasia regardless of the structure of languages mastered pre-morbidly. The implications of these findings for the theories of bilingual agrammatism are discussed.
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    Using Swahili and English to Test Explanations of Agrammatism
    (Psychology press, 2011-05-25) Abuom, Tom O; Obler, Loraine K; Bastiaanse, Roelien
    Background: This study is on time reference through verbs in two Swahili-English bilingual agrammatic speakers. Recent studies in several languages have shown that time reference through verb inflection, and more specifically through tense, is impaired in agrammatic speakers. Consequently, several theories have been proposed to account for this phenomenon. We explore three kinds of theories of agrammatism that are eligible to account for these data: (1) a deficit in Tense; (2) a deficit in Discourse Linking; (3) a Morphological-System deficit. Aims: The study investigated the patterns and degree of severity of time reference impairments in bilingual agrammatic speakers of Swahili and English. Production of past and future verb forms was examined in both languages to determine which of the explanations for verb inflection errors holds in bilingual agrammatic speakers. Methods & Procedures: A sentence completion test was developed in two languages to elicit sentence constructions that refer to the past and the future. This test was administered to two bilingual agrammatic speakers of Swahili and English and three age- and education-matched control participants. Outcomes & Results: The performance of the control participants on the two tests was perfect in both languages. Similarly, the two agrammatic speakers’ performance in Swahili as well as future tense in English was at ceiling. However, both agrammatic speakers had selective deficits in the production of English past tense. Conclusions: The discrepancy between the English and Swahili data cannot be explained by a syntactic or discourse linking theory. Only a morphological deficit in terms of number of possible candidates for a particular inflectional form fits with the data.