<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>13</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bram Vandekerckhove</style></author><author><style face="normal" font="default" size="100%">Dominiek Sandra</style></author><author><style face="normal" font="default" size="100%">Walter Daelemans</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Impaired knowledge of adjective order constraints as overeager abstraction</style></title><secondary-title><style face="normal" font="default" size="100%">Talk given at the 10th Psycholinguistics in Flanders workshop (PIF2011), Antwerp, Belgium.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">adjectives</style></keyword><keyword><style  face="normal" font="default" size="100%">case-based reasoning</style></keyword><keyword><style  face="normal" font="default" size="100%">representation</style></keyword><keyword><style  face="normal" font="default" size="100%">semantics</style></keyword><keyword><style  face="normal" font="default" size="100%">symbolic computational modeling</style></keyword><keyword><style  face="normal" font="default" size="100%">syntax</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">25/06/2011</style></date></pub-dates></dates><abstract><style face="normal" font="default" size="100%">Kemmerer et al. (2009) reported patients with brain lesions who were selectively impaired in their knowledge of prenominal adjective order. They failed a test that required them to discriminate between preferred and dispreferred adjective orders (e.g., a big brown dog vs. a brown big dog) (Task 1), but passed an adjective similarity judgment task (e.g. whether the adjective good was more similar to bad or to tiny) (Task 3). They were also still able to discriminate between correct and incorrect orderings of adjectives in relation to other parts of speech (e.g., big field vs. field big) (Task 2).
In this study, we provide an explicit cognitive characterization of these patients as overeager abstractors. To simulate the performance of the patients, we varied the amount of smoothing, i.e., the number of nearest neighbors that was used for extrapolation, in a similarity-smoothed bigram word prediction model. Performance on Task 1 already started to break down when taking relatively few neighbors into account (&gt; 5). Performance on Task 2 was more robust to oversmoothing and only started to decrease when extrapolating from a much larger number of neighbors (&gt; 10,000). A Wilcoxon rank sum test showed that the mean rank of the per-item breakdown level was significantly higher for Task 2 (Mdn = 30,000) than for Task 1 (Mdn = 400), W = 281, p (one-tailed) = .002. At the same time, the model's accuracy on Task 3 (19 out of 25 items correct) showed that the model’s metric captured relevant semantic similarities between the adjectives.
According to the overeager abstraction hypothesis, the items for which the model starts to predict the wrong order at low levels of abstraction should also be the most difficult for the patients to get right. We tested this prediction in a mixed logit model.  We found a positive effect of this breakdown level on the probability that the impaired patients chose the correct adjective order, B = 0.12 (SE = 0.05), p = .007, and a negative interaction effect with group (impaired vs. unimpaired), B = -0.12 (SE = 0.06), p = .045.
Together, these findings provide strong support for our claim that the patients reported by Kemmerer et al. (2009) can be characterized as overeager abstractors.

References:
Kemmerer, D., Tranel, D., &amp; Zdanczyk, C. (2009). Knowledge of the semantic constraints on adjective order can be selectively impaired. Journal of Neurolinguistics, 22, 91–108.
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