TY  - JOUR
A1  - Pregla, Dorothea
A1  - Lissón Hernández, Paula J.
A1  - Vasishth, Shravan
A1  - Burchert, Frank
A1  - Stadie, Nicole
T1  - Variability in sentence comprehension in aphasia in German
JF  - Brain & language : a journal of the neurobiology of language
N2  - An important aspect of aphasia is the observation of behavioral variability between and within individual participants. Our study addresses variability in sentence comprehension in German, by testing 21 individuals with aphasia and a control group and involving (a) several constructions (declarative sentences, relative clauses and control structures with an overt pronoun or PRO), (b) three response tasks (object manipulation, sentence-picture matching with/without self-paced listening), and (c) two test phases (to investigate test-retest performance). With this systematic, large-scale study we gained insights into variability in sentence comprehension. We found that the size of syntactic effects varied both in aphasia and in control participants. Whereas variability in control participants led to systematic changes, variability in individuals with aphasia was unsystematic across test phases or response tasks. The persistent occurrence of canonicity and interference effects across response tasks and test phases, however, shows that the performance is systematically influenced by syntactic complexity.
KW  - Aphasia
KW  - Sentence Comprehension
KW  - Variability
KW  - Test-retest reliability
KW  - Task demands
KW  - Canonicity and interference effects
KW  - Object manipulation
KW  - Sentence-picture matching
KW  - Self-paced listening
KW  - Adaptation
Y1  - 2021
U6  - https://doi.org/10.1016/j.bl.2021.105008
SN  - 0093-934X
SN  - 1090-2155
VL  - 222
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Patil, Umesh
A1  - Hanne, Sandra
A1  - Burchert, Frank
A1  - De Bleser, Ria
A1  - Vasishth, Shravan
T1  - A Computational Evaluation of Sentence Processing Deficits in Aphasia
JF  - Cognitive science : a multidisciplinary journal of anthropology, artificial intelligence, education, linguistics, neuroscience, philosophy, psychology ; journal of the Cognitive Science Society
N2  - Individuals with agrammatic Broca's aphasia experience difficulty when processing reversible non-canonical sentences. Different accounts have been proposed to explain this phenomenon. The Trace Deletion account (Grodzinsky, 1995, 2000, 2006) attributes this deficit to an impairment in syntactic representations, whereas others (e.g., Caplan, Waters, Dede, Michaud, & Reddy, 2007; Haarmann, Just, & Carpenter, 1997) propose that the underlying structural representations are unimpaired, but sentence comprehension is affected by processing deficits, such as slow lexical activation, reduction in memory resources, slowed processing and/or intermittent deficiency, among others. We test the claims of two processing accounts, slowed processing and intermittent deficiency, and two versions of the Trace Deletion Hypothesis (TDH), in a computational framework for sentence processing (Lewis & Vasishth, 2005) implemented in ACT-R (Anderson, Byrne, Douglass, Lebiere, & Qin, 2004). The assumption of slowed processing is operationalized as slow procedural memory, so that each processing action is performed slower than normal, and intermittent deficiency as extra noise in the procedural memory, so that the parsing steps are more noisy than normal. We operationalize the TDH as an absence of trace information in the parse tree. To test the predictions of the models implementing these theories, we use the data from a German sentence—picture matching study reported in Hanne, Sekerina, Vasishth, Burchert, and De Bleser (2011). The data consist of offline (sentence-picture matching accuracies and response times) and online (eye fixation proportions) measures. From among the models considered, the model assuming that both slowed processing and intermittent deficiency are present emerges as the best model of sentence processing difficulty in aphasia. The modeling of individual differences suggests that, if we assume that patients have both slowed processing and intermittent deficiency, they have them in differing degrees.
KW  - Aphasia
KW  - Non-canonical sentences
KW  - Sentence-picture matching
KW  - Eye movements
KW  - Computational modeling
KW  - Cognitive architecture
KW  - Individual differences
Y1  - 2016
U6  - https://doi.org/10.1111/cogs.12250
SN  - 0364-0213
SN  - 1551-6709
VL  - 40
SP  - 5
EP  - 50
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -