TY - JOUR A1 - Hameister, Inga A1 - Nickels, Lyndsey T1 - The cat in the tree - using picture descriptions to inform our understanding of conceptualisation in aphasia JF - Language, cognition and neuroscience N2 - Conceptualisation is the first step of speech production and describes the process by which we map our thoughts onto spoken language. Recent studies suggest that some people with language impairments have conceptualisation deficits manifested by information selection and sequencing difficulties. In this study, we examined conceptualisation in the complex picture descriptions of individuals with and without aphasia. We analysed the number and the order of main concepts (ideas produced by >= 60% of unimpaired speakers) and non-main concepts (e.g. irrelevant details). Half of the individuals with aphasia showed a reduced number of main concepts that could not be fully accounted for by their language production deficits. Moreover, individuals with aphasia produced both a larger amount of marginally relevant information, as well as having greater variability in the order of main concepts. Both findings provide support for the idea that conceptualisation deficits are a relatively common impairment in people with aphasia. KW - Aphasia KW - conceptualisation KW - discourse KW - concept analysis KW - macroplanning Y1 - 2018 U6 - https://doi.org/10.1080/23273798.2018.1497801 SN - 2327-3798 SN - 2327-3801 VL - 33 IS - 10 SP - 1296 EP - 1314 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Arantzeta, Miren A1 - Webster, Janet A1 - Laka, Itziar A1 - Martinez-Zabaleta, Maite A1 - Howard, David T1 - What happens when they think they are right? BT - Error awareness analysis of sentence comprehension deficits in aphasia JF - Aphasiology : an international, interdisciplinary journal N2 - Background: Comprehension of non-canonical sentences is frequently characterised by chance level performance in people with aphasia (PWA). Chance level performance has been interpreted as guessing, but online data does not support this rendering. It is still not clear whether the incorrect sentence processing is guided by the compensatory strategies that PWA might employ to overcome linguistic difficulties.Aims: We aim to study to what extent people with non-fluent aphasia are aware of their sentence comprehension deficits.Methods & Procedures: This study combined offline and online data to investigate the effect of word order and error-awareness on sentence comprehension in a group of PWA and non-brain damaged (NBD) participants. The offline tasks involved auditory sentence picture-matching immediately followed by a confidence rating (CR). Participants were asked to judge the perceived correctness of their previous answer. Online data consisted of eye-tracking.Outcomes & Results: Replicating previous findings, PWA had significantly worse comprehension of Theme-Agent order compared to Agent-Theme order sentences. Controls showed ceiling level sentence comprehension. CR was a poor predictor of response accuracy in PWA, but moderate-good in NBD. A total of 6.8% of judgements were classified as guessing by PWA. Post hoc gaze data analysis indicated that CR was a predictor of the fixation pattern during the presentation of the linguistic stimuli.Conclusions: Results suggest that PWA were mostly unaware of their sentence comprehension errors and did not consciously employ strategies to compensate for their difficulties. KW - Aphasia KW - sentence comprehension KW - error awareness KW - eye-tracking KW - anosognosia Y1 - 2018 U6 - https://doi.org/10.1080/02687038.2017.1423270 SN - 0268-7038 SN - 1464-5041 VL - 32 IS - 12 SP - 1418 EP - 1444 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Mätzig, Paul A1 - Vasishth, Shravan A1 - Engelmann, Felix A1 - Caplan, David A1 - Burchert, Frank T1 - A computational investigation of sources of variability in sentence comprehension difficulty in aphasia JF - Topics in cognitive science N2 - We present a computational evaluation of three hypotheses about sources of deficit in sentence comprehension in aphasia: slowed processing, intermittent deficiency, and resource reduction. The ACT-R based Lewis and Vasishth (2005) model is used to implement these three proposals. Slowed processing is implemented as slowed execution time of parse steps; intermittent deficiency as increased random noise in activation of elements in memory; and resource reduction as reduced spreading activation. As data, we considered subject vs. object relative sentences, presented in a self-paced listening modality to 56 individuals with aphasia (IWA) and 46 matched controls. The participants heard the sentences and carried out a picture verification task to decide on an interpretation of the sentence. These response accuracies are used to identify the best parameters (for each participant) that correspond to the three hypotheses mentioned above. We show that controls have more tightly clustered (less variable) parameter values than IWA; specifically, compared to controls, among IWA there are more individuals with slow parsing times, high noise, and low spreading activation. We find that (a) individual IWA show differential amounts of deficit along the three dimensions of slowed processing, intermittent deficiency, and resource reduction, (b) overall, there is evidence for all three sources of deficit playing a role, and (c) IWA have a more variable range of parameter values than controls. An important implication is that it may be meaningless to talk about sources of deficit with respect to an abstract verage IWA; the focus should be on the individual's differential degrees of deficit along different dimensions, and on understanding the causes of variability in deficit between participants. KW - Sentence comprehension KW - Aphasia KW - Computational modeling KW - Cue-based retrieval Y1 - 2018 U6 - https://doi.org/10.1111/tops.12323 SN - 1756-8757 SN - 1756-8765 VL - 10 IS - 1 SP - 161 EP - 174 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Zakarias, Lilla A1 - Salis, Christos A1 - Wartenburger, Isabell T1 - Transfer effects on spoken sentence comprehension and functional communication after working memory training in stroke aphasia JF - Journal of neurolinguistics : an international journal for the study of brain function in language behavior and experience N2 - Recent treatment protocols have been successful in improving working memory (WM) in individuals with aphasia. However, the evidence to date is small and the extent to which improvements in trained tasks of WM transfer to untrained memory tasks, spoken sentence comprehension, and functional communication is yet poorly understood. To address these issues, we conducted a multiple baseline study with three German-speaking individuals with chronic post stroke aphasia. Participants practised two computerised WM tasks (n-back with pictures and aback with spoken words) four times a week for a month, targeting two WM processes: updating WM representations and resolving interference. All participants showed improvement on at least one measure of spoken sentence comprehension and everyday memory activities. Two of them showed improvement also on measures of WM and functional communication. Our results suggest that WM can be improved through computerised training in chronic aphasia and this can transfer to spoken sentence comprehension and functional communication in some individuals. KW - Aphasia KW - Working memory KW - n-back training KW - Transfer KW - Sentence comprehension KW - Verbal communication Y1 - 2018 U6 - https://doi.org/10.1016/j.jneuroling.2017.12.002 SN - 0911-6044 VL - 48 SP - 47 EP - 63 PB - Elsevier CY - Oxford ER -