@article{HanneSekerinaVasishthetal.2011, author = {Hanne, Sandra and Sekerina, Irina A. and Vasishth, Shravan and Burchert, Frank and De Bleser, Ria}, title = {Chance in agrammatic sentence comprehension what does it really mean? Evidence from eye movements of German agrammatic aphasic patients}, series = {Aphasiology : an international, interdisciplinary journal}, volume = {25}, journal = {Aphasiology : an international, interdisciplinary journal}, number = {2}, publisher = {Wiley}, address = {Hove}, issn = {0268-7038}, doi = {10.1080/02687038.2010.489256}, pages = {221 -- 244}, year = {2011}, abstract = {Background: In addition to the canonical subject-verb-object (SVO) word order, German also allows for non-canonical order (OVS), and the case-marking system supports thematic role interpretation. Previous eye-tracking studies (Kamide et al., 2003; Knoeferle, 2007) have shown that unambiguous case information in non-canonical sentences is processed incrementally. For individuals with agrammatic aphasia, comprehension of non-canonical sentences is at chance level (Burchert et al., 2003). The trace deletion hypothesis (Grodzinsky 1995, 2000) claims that this is due to structural impairments in syntactic representations, which force the individual with aphasia (IWA) to apply a guessing strategy. However, recent studies investigating online sentence processing in aphasia (Caplan et al., 2007; Dickey et al., 2007) found that divergences exist in IWAs' sentence-processing routines depending on whether they comprehended non-canonical sentences correctly or not, pointing rather to a processing deficit explanation. Aims: The aim of the current study was to investigate agrammatic IWAs' online and offline sentence comprehension simultaneously in order to reveal what online sentence-processing strategies they rely on and how these differ from controls' processing routines. We further asked whether IWAs' offline chance performance for non-canonical sentences does indeed result from guessing. Methods Procedures: We used the visual-world paradigm and measured eye movements (as an index of online sentence processing) of controls (N = 8) and individuals with aphasia (N = 7) during a sentence-picture matching task. Additional offline measures were accuracy and reaction times. Outcomes Results: While the offline accuracy results corresponded to the pattern predicted by the TDH, IWAs' eye movements revealed systematic differences depending on the response accuracy. Conclusions: These findings constitute evidence against attributing IWAs' chance performance for non-canonical structures to mere guessing. Instead, our results support processing deficit explanations and characterise the agrammatic parser as deterministic and inefficient: it is slowed down, affected by intermittent deficiencies in performing syntactic operations, and fails to compute reanalysis even when one is detected.}, language = {en} } @article{KadyamusumaDeBleserMayer2011, author = {Kadyamusuma, McLoddy R. and De Bleser, Ria and Mayer, J{\"o}rg}, title = {Perceptual discrimination of Shona lexical tones and low-pass filtered speech by left and right hemisphere damaged patients}, series = {Aphasiology : an international, interdisciplinary journal}, volume = {25}, journal = {Aphasiology : an international, interdisciplinary journal}, number = {5}, publisher = {Wiley}, address = {Hove}, issn = {0268-7038}, doi = {10.1080/02687038.2010.540336}, pages = {576 -- 592}, year = {2011}, abstract = {Background: While the role of the right hemisphere (RH) in prosodic processing is prominent, research on the perception of lexical tones has shown that left hemisphere damaged (LHD) patients are more impaired than right hemisphere damaged (RHD) patients. Dichotic listening and imaging studies with healthy speakers of tone languages demonstrate that at least at the phonemic and lexical level, prosody is processed in the left hemisphere (LH) when the variations in pitch are phonemically distinctive. There is no report available yet on the perceptual discrimination of a Bantu language in patients after unilateral brain damage. Aims: We addressed the question of how well Shona aphasic patients and right hemisphere damaged patients perceive pitch contrasts in Shona lexical words and also in their homologous low-pass filtered counterparts. We also sought to discover the validity of the current hypotheses on hemispheric lateralisation particularly the hypothesis on hemispheric lateralisation based on language function to account for the Shona data. Methods Procedures: A total of 7 LHD and 7 RHD patients and 14 healthy controls participated in two discrimination tasks that examined perception of lexical tone in (a) bisyllabic Shona words and (b) low-pass filtered stimuli. In both tasks the participants were tasked with judging the pitch as the same or different in 120 bisyllabic words and 120 low-pass filtered stimuli. Outcomes Results: The results demonstrated that the tonal discrimination of the LHD group was more reduced in comparison to the RHD group and control participants. However, the performance of the RHD patients was not error free relative to the control participants, although significantly better than the LHD patients in both tasks. Conclusions: At least for the phonemic and lexical levels, brain damage to the dominant hemisphere results in lexical tone impairment for LHD patients, and cognitive load processing results in a subdued but good performance for RHD patients. The LH is therefore dominant for processing tone when it is lexically distinctive.}, language = {en} } @article{KadyamusumaDeBleserMayer2011, author = {Kadyamusuma, McLoddy R. and De Bleser, Ria and Mayer, J{\"o}rg}, title = {Lexical tone disruption in Shona after brain damage}, series = {Aphasiology : an international, interdisciplinary journal}, volume = {25}, journal = {Aphasiology : an international, interdisciplinary journal}, number = {10}, publisher = {Wiley}, address = {Hove}, issn = {0268-7038}, doi = {10.1080/02687038.2011.590966}, pages = {1239 -- 1260}, year = {2011}, abstract = {Background: The issue of production and perception of lexical tone in patients with brain lesions has been investigated mainly through East Asian languages and Norwegian. The present study investigated the lateralisation of lexical tone in Shona, a Bantu language. Van Lancker (1980) proposed a continuum scale of the levels of functional pitch in the speech signal. According to the functional lateralisation account (FLH), the left hemisphere (LH) is associated with highly structured pitch contrasts, such as phonological tone, whereas the right hemisphere (RH) is specialised for the least structured pitch functions cueing emotional and personal information. The extant data show that the ability to produce and identify lexical tone is frequently more impaired as a result of lesions to the LH than RH lesions. Aims: The present investigation focused on the lateralisation of lexical tone in Shona speakers. The study sought to validate if the scale of hemispheric lateralisation as proposed by Van Lancker (1980) is also valid for Shona, a Bantu language. Methods \& Procedures: We examined five LH damaged (LHD) patients and five RH (RHD) damaged patients using a confrontational picture-naming task and a lexical tone identification task of Shona lexical tone. The first experiment investigated the ability of LHD patients and RHD patients to identify Shona lexical tone in 60 disyllabic minimal pairs. The second experiment examined the ability of Shona brain-damaged patients to produce lexical tone using a confrontational picture-naming task with 120 lexical items. Outcomes \& Results: We observed a dissociation in the performance of both the LHD and RHD patients in the two tasks. Both groups were impaired in the tone identification task relative to the non-brain-damaged controls. However, RHD patients performed significantly better than the LHD patients in the tone identification task. On the other hand, both LHD and RHD groups were equally impaired in the tone production task in comparison to the controls. Conclusions: The discrepancy in the production and perception of Shona lexical tone for this group of brain-damaged patients shows that, although the two modes are related, they do not always get disrupted at the same level after brain damage. The results from the tone identification task suggest to a certain extent that the FLH is also valid for Shona. In order to account for all the data there is need to carefully consider alternative accounts like the acoustic cue hypothesis (Van Lancker \& Sidtis, 1992).}, language = {en} } @article{TsegayeDeBleserIribarren2011, author = {Tsegaye, Mulugeta Tarekegne and De Bleser, Ria and Iribarren, Carolina}, title = {The effect of literacy on oral language processing implications for aphasia tests}, series = {Clinical linguistics \& phonetics}, volume = {25}, journal = {Clinical linguistics \& phonetics}, number = {6-7}, publisher = {Taylor \& Francis Group}, address = {London}, issn = {0269-9206}, doi = {10.3109/02699206.2011.567348}, pages = {628 -- 639}, year = {2011}, abstract = {Most studies investigating the impact of literacy on oral language processing have shown that literacy provides phonological awareness skills in the processing of oral language. The implications of these results on aphasia tests could be significant and pose questions on the adequacy of such tools for testing non-literate individuals. Aiming at examining the impact of literacy on oral language processing and its implication on aphasia tests, this study tested 12 non-literate and 12 literate individuals with a modified Amharic version of the Bilingual Aphasia Test (Paradis and Amberber, 1991, Bilingual Aphasia Test. Amharic version. Hillsdale, NJ: Lawrence Erlbaum.). The problems of phonological awareness skills in oral language processing in non-literates are substantiated. In addition, compared with literate participants, non-literate individuals demonstrated difficulties in the word/sentence-picture matching tasks. This study has also revealed that the Amharic version of the Bilingual Aphasia Test may be viable for testing Amharic-speaking non-literate individuals with aphasia when modifications are incorporated.}, language = {en} }