Electrical Stimulation of Broca's Area Enhances Implicit Learning of an Artificial Grammar
Electrical Stimulation of Broca's Area Enhances Implicit Learning of an Artificial Grammar
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DOI：
10.1162/jocn.2009.21385
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发表时间：
2010-11-01
影响因子：
3.2
通讯作者：
Floeel, Agnes
中科院分区：
文献类型：
--
作者：
de Vries, Meinou H.;Barth, Andre C. R.;Floeel, Agnes
人工语法学习构成了在自然环境中习得语法知识的成熟模式。以前的神经成像研究表明，Broca区(左侧BA 44/45)类似地被自然句法处理和人工语法学习激活。本研究旨在通过经颅直流电刺激(Tdcs)研究Broca区与人工语法学习之间的因果关系。38名健康受试者参加了受试者间设计，在获得人工语法的过程中，在Broca‘s区进行阳极tdcs(20min，1 mA)或假刺激。习得阶段的表现表现为一项工作记忆任务，在不同组之间具有可比性。在随后的分类任务中，检测句法违规，特别是那些没有表面相似性线索的分类任务，在阳极tDC之后显著提高，导致总体上更好的表现。在一项对照实验中，10名受试者在一个与人工语法学习无关的区域接受了负极tdcs，进一步支持了这些效应对布罗卡区的特异性。我们的结论是，布罗卡的领域特别涉及基于规则的知识，在这里，提高了检测句法违规的能力。这一结果不能用tdcs在习得阶段更好的工作记忆表现来解释。这是第一个研究表明tdcs可以促进语法知识的获得，这是对失语症康复的潜在兴趣的发现。
Artificial grammar learning constitutes a well-established model for the acquisition of grammatical knowledge in a natural setting. Previous neuroimaging studies demonstrated that Broca's area (left BA 44/45) is similarly activated by natural syntactic processing and artificial grammar learning. The current study was conducted to investigate the causal relationship between Broca's area and learning of an artificial grammar by means of transcranial direct current stimulation (tDCS). Thirty-eight healthy subjects participated in a between-subject design, with either anodal tDCS (20 min, 1 mA) or sham stimulation, over Broca's area during the acquisition of an artificial grammar. Performance during the acquisition phase, presented as a working memory task, was comparable between groups. In the subsequent classification task, detecting syntactic violations, and specifically, those where no cues to superficial similarity were available, improved significantly after anodal tDCS, resulting in an overall better performance. A control experiment where 10 subjects received anodal tDCS over an area unrelated to artificial grammar learning further supported the specificity of these effects to Broca's area. We conclude that Broca's area is specifically involved in rule-based knowledge, and here, in an improved ability to detect syntactic violations. The results cannot be explained by better tDCS-induced working memory performance during the acquisition phase. This is the first study that demonstrates that tDCS may facilitate acquisition of grammatical knowledge, a finding of potential interest for rehabilitation of aphasia.