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标题：Laterality Mediates the Benefits of Neurostimulation on New Language Learning
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作者：A. Woolllams ; A. Woolllams ; I. McMillan 等
期刊名称：Procedia - Social and Behavioral Sciences
印刷版ISSN：1877-0428
出版年度：2013
卷号：94
页码：230-231
DOI：10.1016/j.sbspro.2013.09.114
语种：English
出版社：Elsevier
摘要：New word learning paradigms in healthy adults have become popular in recent times as this allowsconsideration of the mechanisms involved in relearning amongst aphasic patients with tightexperimental control (Breitenstein et al., 2007). Anodal transcranial Direct Current Stimulation(tDCS) has been used to facilitate the acquisition of novel labels for familiar items (Floel et al.,2008). To date, however, the impact of site and polarity of stimulation on new language learning inhealthy adults has yet to be explored. Current neural theories of speech processing suggest thatspeech production is a strongly left lateralised ability, whereas comprehension involves morebilateral processing (Hickok & Poeppel, 2007). These models make clear predictions for the impactof neurostimulation upon new word learning. When stimulating speech production areas, this shouldonly impact upon acquisition of novel object labels if applied to the left. In contrast, whenstimulating areas involved in speech comprehension, comparable effects should be observed whetherapplied to the left or right. These predictions were tested in the current study in two experiments.Firstly, anodal (positive), cathodal (negative), and sham (neutral) tDCS were applied a left or rightfrontal region corresponding to Broca’s area and its homologue, as this left hemisphere area has beenimplicated in speech production in stroke aphasia (Fridriksson et al., 2010). In line with predictions,acquisition of novel labels for known objects was enhanced only for left anodal frontal stimulation,and this generalised to a different view of the object and persisted a week later. Secondly, anodal,cathodal, and sham tDCS were applied to a left or right anterior temporal region. These areas areimplicated in speech comprehension given the deficits seen in this domain amongst semanticdementia patients, who are characterised by bilateral damage to the anterior temporal lobes (Ogar etal., 2011). Again in line with predictions, acquisition of novel labels for novel objects was enhancedby both left and right anodal anterior temporal stimulation up to a week later, although this effect didnot generalise to a different view. Taken together, these results clearly illustrate the task dependentlateralisation of the speech processing system, suggesting that careful consideration needs to begiven to both the site of stimulation and nature of the task in application of tDCS to treatment ofword finding difficulties in aphasic patients.Ref.