Papers by Tuba Yarbay Duman
Journal of Speech Language and Hearing Research, 2015
This study investigated the comprehension of counterfactual conditionals in monolingual Turkish c... more This study investigated the comprehension of counterfactual conditionals in monolingual Turkish children with specific language impairment (SLI) and typically developing (TD) children. Comprehending counterfactuals requires a well-developed cognitive system (Beck, Riggs, & Gorniak, 2009). Children with SLI have impaired cognitive functioning (Im Bolter, Johnston, & Pascaul-Leone, 2006) and this impacts on their ability to comprehend counterfactuals. The sample consisted of 13 children with SLI who were matched on age and nonverbal IQ with 13 TD children (mean age 6;9 [years; months] for both groups). Each group completed a sentence comprehension and repetition task with three sentence conditions: nonconditional, factual and counterfactual. Nonconditionals do not have if-embedding whereas factual and counterfactual conditionals are morphosyntactically equivalent if-clauses, but only the latter is cognitively complex. Conditionals were more difficult to comprehend than nonconditionals for both groups. Counterfactuals were more difficult to comprehend than the morphosyntactically equivalent factual counterparts for the SLI group. There was no discrepancy between the groups for repetition of counterfactuals and factuals. Children with SLI have difficulty processing counterfactuals due to morphosyntactic complexity (if-embedding) and the cognitive processes involved in comprehending counterfactuals. This indicates that cognitive complexity adds to sentence comprehension deficits in SLI.
Journal of Neurolinguistics, 2011
Talks by Tuba Yarbay Duman
Groningen University Press
The production and comprehension of finite verbs that are inflected for tense and aspect can be c... more The production and comprehension of finite verbs that are inflected for tense and aspect can be compromised in several language-impaired populations. In Broca’s aphasia, difficulty with tense and aspect is often regarded as a deficiency with past time reference (Yarbay Duman, 2009; Yarbay Duman et. al., 2011; Bastiaanse et. al., 2011).
Although time-reference is mostly expressed through tense, it also highly interacts with aspect and modality in many languages. While tense presumes the concept of a temporal axis along which events are ordered with anteriority-posteriority relations with respect to a time-point, aspectual morphology informs about semantic distinctions regarding temporal characteristics like progression or completion of events (Aksu-Koc, 2006). Completion, for example, coincides with past tense since an event regarded as completed is, in general, anterior to the moment of speech or to some other point in time. Epistemic modality (the degree of certainty the speaker has with respect to her proposition) determines grammatical morphology used for Tense and Aspect. For example, the speaker uses simple past tense with perfect aspect to indicate certainty that an event has happened. Linguistic information on Tense, Aspect and Modality in a sentence needs to be integrated to indicate time-reference of an event since time reference is a semantic characteristic of a verb complex as a whole.
Yarbay Duman et al. (2011) proposed the Integration Problem Hypothesis (IPH), stating that past time reference is more difficult than non-past time reference for agrammatic speakers because interpreting the temporal information in aspect / modality is more difficult for agrammatic speakers when there is certainty of past i.e. certainty that an event has happened or completed. However, the IPH also predicts that integrating semantic information about aspect and morphosyntactic information about tense will be difficult for agrammatic speakers. Dragoy and Bastiaanse (2013) presented evidence from a Russian study supporting this hypothesis: in Broca’s aphasia, prototypical reference to the non-past (present imperfect and future imperfect) was better preserved than reference to the past (past imperfect). This non-past time advantage, however, disappeared for non-prototypical future perfect when a perfective Russian verb was used to refer to a future time.
Although studies in Broca’s aphasia report that problems with tense and aspect extend beyond a pure morphosyntactic impairment, tense-related problems in SLI have primarily been characterized as a result of incomplete or optional feature specification of tense features within the functional category T/Infl (e.g., omission of finiteness markings and insensitivity to tense omissions in English) (Rice & Wexler 1996). Leonard and Deevy (2010) argued that aspect is not intact in children with SLI as these children have problems understanding completeness cues in past tense contexts compared to the present tense contexts. Our present study investigates whether tense in Turkish children with SLI is impaired as a functional category T/Infl or whether tense-related difficulties are by-products of an integration problem (such as that observed in Broca’s aphasia).
In typical development, children initially use aspect to mark tense before passing through four stages to acquire the tense/aspect/modality system of Turkish (Aksu-Koc, 2006): (1) differentiating static and ongoing events; (2) using –DI and –IYOR to comment on COMPLETED versus ONGOING events within the boundaries of the immediate present; (3) use of modal functions: –DI marks for certainty that an event has happened and a past non-past distinction is made (includes future) and (4) all tense/aspect/modality inflections are used to place events in time and to add perspective.
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Papers by Tuba Yarbay Duman
Talks by Tuba Yarbay Duman
Although time-reference is mostly expressed through tense, it also highly interacts with aspect and modality in many languages. While tense presumes the concept of a temporal axis along which events are ordered with anteriority-posteriority relations with respect to a time-point, aspectual morphology informs about semantic distinctions regarding temporal characteristics like progression or completion of events (Aksu-Koc, 2006). Completion, for example, coincides with past tense since an event regarded as completed is, in general, anterior to the moment of speech or to some other point in time. Epistemic modality (the degree of certainty the speaker has with respect to her proposition) determines grammatical morphology used for Tense and Aspect. For example, the speaker uses simple past tense with perfect aspect to indicate certainty that an event has happened. Linguistic information on Tense, Aspect and Modality in a sentence needs to be integrated to indicate time-reference of an event since time reference is a semantic characteristic of a verb complex as a whole.
Yarbay Duman et al. (2011) proposed the Integration Problem Hypothesis (IPH), stating that past time reference is more difficult than non-past time reference for agrammatic speakers because interpreting the temporal information in aspect / modality is more difficult for agrammatic speakers when there is certainty of past i.e. certainty that an event has happened or completed. However, the IPH also predicts that integrating semantic information about aspect and morphosyntactic information about tense will be difficult for agrammatic speakers. Dragoy and Bastiaanse (2013) presented evidence from a Russian study supporting this hypothesis: in Broca’s aphasia, prototypical reference to the non-past (present imperfect and future imperfect) was better preserved than reference to the past (past imperfect). This non-past time advantage, however, disappeared for non-prototypical future perfect when a perfective Russian verb was used to refer to a future time.
Although studies in Broca’s aphasia report that problems with tense and aspect extend beyond a pure morphosyntactic impairment, tense-related problems in SLI have primarily been characterized as a result of incomplete or optional feature specification of tense features within the functional category T/Infl (e.g., omission of finiteness markings and insensitivity to tense omissions in English) (Rice & Wexler 1996). Leonard and Deevy (2010) argued that aspect is not intact in children with SLI as these children have problems understanding completeness cues in past tense contexts compared to the present tense contexts. Our present study investigates whether tense in Turkish children with SLI is impaired as a functional category T/Infl or whether tense-related difficulties are by-products of an integration problem (such as that observed in Broca’s aphasia).
In typical development, children initially use aspect to mark tense before passing through four stages to acquire the tense/aspect/modality system of Turkish (Aksu-Koc, 2006): (1) differentiating static and ongoing events; (2) using –DI and –IYOR to comment on COMPLETED versus ONGOING events within the boundaries of the immediate present; (3) use of modal functions: –DI marks for certainty that an event has happened and a past non-past distinction is made (includes future) and (4) all tense/aspect/modality inflections are used to place events in time and to add perspective.
Although time-reference is mostly expressed through tense, it also highly interacts with aspect and modality in many languages. While tense presumes the concept of a temporal axis along which events are ordered with anteriority-posteriority relations with respect to a time-point, aspectual morphology informs about semantic distinctions regarding temporal characteristics like progression or completion of events (Aksu-Koc, 2006). Completion, for example, coincides with past tense since an event regarded as completed is, in general, anterior to the moment of speech or to some other point in time. Epistemic modality (the degree of certainty the speaker has with respect to her proposition) determines grammatical morphology used for Tense and Aspect. For example, the speaker uses simple past tense with perfect aspect to indicate certainty that an event has happened. Linguistic information on Tense, Aspect and Modality in a sentence needs to be integrated to indicate time-reference of an event since time reference is a semantic characteristic of a verb complex as a whole.
Yarbay Duman et al. (2011) proposed the Integration Problem Hypothesis (IPH), stating that past time reference is more difficult than non-past time reference for agrammatic speakers because interpreting the temporal information in aspect / modality is more difficult for agrammatic speakers when there is certainty of past i.e. certainty that an event has happened or completed. However, the IPH also predicts that integrating semantic information about aspect and morphosyntactic information about tense will be difficult for agrammatic speakers. Dragoy and Bastiaanse (2013) presented evidence from a Russian study supporting this hypothesis: in Broca’s aphasia, prototypical reference to the non-past (present imperfect and future imperfect) was better preserved than reference to the past (past imperfect). This non-past time advantage, however, disappeared for non-prototypical future perfect when a perfective Russian verb was used to refer to a future time.
Although studies in Broca’s aphasia report that problems with tense and aspect extend beyond a pure morphosyntactic impairment, tense-related problems in SLI have primarily been characterized as a result of incomplete or optional feature specification of tense features within the functional category T/Infl (e.g., omission of finiteness markings and insensitivity to tense omissions in English) (Rice & Wexler 1996). Leonard and Deevy (2010) argued that aspect is not intact in children with SLI as these children have problems understanding completeness cues in past tense contexts compared to the present tense contexts. Our present study investigates whether tense in Turkish children with SLI is impaired as a functional category T/Infl or whether tense-related difficulties are by-products of an integration problem (such as that observed in Broca’s aphasia).
In typical development, children initially use aspect to mark tense before passing through four stages to acquire the tense/aspect/modality system of Turkish (Aksu-Koc, 2006): (1) differentiating static and ongoing events; (2) using –DI and –IYOR to comment on COMPLETED versus ONGOING events within the boundaries of the immediate present; (3) use of modal functions: –DI marks for certainty that an event has happened and a past non-past distinction is made (includes future) and (4) all tense/aspect/modality inflections are used to place events in time and to add perspective.