Vocabulary relearning in semantic dementia: Positive and negative consequences of increasing variability in the learning experience

NEUROPSYCHOLOGIA

卷:76

Article

Hoffman, Paul^1,2  Clarke, Natasha³  Jones, Roy W.³  Noonan, Krist A.³ 

[1] Univ Manchester, NARU, Manchester M13 9PL, Lancs, England

[2] Univ Edinburgh, Dept Psychol, CCACE, Edinburgh EH8 9JZ, Midlothian, Scotland

[3] Res Inst Care Older People RICE, Bath, Avon, England

关键词: Semantic dementia;    Anomia therapy;    Word relearning;    Generalisation;    Conceptual knowledge;   

DOI  :  10.1016/j.neuropsychologia.2015.01.015

来源: Elsevier

【 摘 要 】

Anomia therapy typically aims to improve patients' communication ability through targeted practice in naming a set of particular items. For such interventions to be of maximum benefit, the use of trained (or relearned) vocabulary must generalise from the therapy setting into novel situations. We investigated relearning in three patients with semantic dementia, a condition that has been associated with poor generalisation of relearned vocabulary. We tested two manipulations designed to improve generalisation of relearned words by introducing greater variation into the learning experience. In the first study, we found that trained items were retained more successfully when they were presented in a variety of different sequences during learning. In the second study, we found that training items using a range of different pictured exemplars improved the patients' ability to generalise words to novel instances of the same object. However, in one patient this came at the cost of inappropriate over-generalisations, in which trained words were incorrectly used to name semantically or visually similar objects. We propose that more variable learning experiences benefit patients because they shift responsibility for learning away from the inflexible hippocampal learning system and towards the semantic system. The success of this approach therefore depends critically on the integrity of the semantic representations of the items being trained. Patients with naming impairments in the context of relatively mild comprehension deficits are most likely to benefit from this approach, while avoiding the negative consequences of over-generalisation. (C) 2015 The Authors. Published by Elsevier Ltd.

【 授权许可】

Free