A Computational Evaluation of Two Models of Retrieval Processes in Sentence Processing in Aphasia

Can sentence comprehension impairments in aphasia be explained by difficulties arising from dependency completion processes in parsing? Two distinct models of dependency completion difficulty are investigated, the Lewis and Vasishth (2005) activation-based model and the direct-access model (DA; McElree, 2000). These models' predictive performance is compared using data from individuals with aphasia (IWAs) and control participants. The data are from a self-paced listening task involving subject and object relative clauses. The relative predictive performance of the models is evaluated using k-fold cross-validation. For both IWAs and controls, the activation-based model furnishes a somewhat better quantitative fit to the data than the DA. Model comparisons using Bayes factors show that, assuming an activation-based model, intermittent deficiencies may be the best explanation for the cause of impairments in IWAs, although slowed syntax and lexical delayed access may also play a role. This is the first computational evaluation of different models of dependency completion using data from impaired and unimpaired individuals. This evaluation develops a systematic approach that can be used to quantitatively compare the predictions of competing models of language processing.     

Enhancing mental health and well-being outcomes for psychotherapy and counselling through idiographic analysis: A four-quadrant approach

Mental health and well-being outcomes in psychotherapy and counselling have largely been studied through the use of standardised nomothetic measurement. A key limitation is that nomothetic measurement and current statistical analyses do not necessarily capture the outcomes of the complicated and individual psychotherapy processes. There is an increased interest in the use of idiographic patient-reported outcome measures (I-PROMs), which are uniquely useful because they may explore areas of importance that are unexplored by nomothetic outcome measures. We argue that to optimise the value of I-PROMs, it is necessary to consider their contribution alongside standardised nomothetic measures. However, there are important considerations with respect to whether or not I-PROMs from different clients, or indeed from the same client, can be meaningfully explored at a team/service level, and alongside standardised nomothetic outcomes. We provide worked examples on real client data to show that delineating four quadrants of analysis is important to explore the breadth of information: (a) individual progress on single items, (b) individual progress by aggregated scores, (c) team/service-level progress by goal item/theme and (d) team/service-level progress by aggregated scores.