Electrical stimulation of brocas area enhances implicit learning of an artificial grammar

de Vries, M. H., Barth, A. R., Maiworm, S., Knecht, S., Zwitserlood, P., & Flöel, A. (2010). Electrical stimulation of brocas area enhances implicit learning of an artificial grammar. Journal of Cognitive Neuroscience, 22(11), 2427-2436. Retrieved November 13, 2011, from Academic Search Premier.

The purpose of this study was to investigate the relationship between learning artificial grammar through transcranial direct current stimulation (tDCS) and Broca’s area.  In previous studies Brocaʼs area had been found to be involved in artificial grammar learning through fMRI experiments and TMS experiments.  More specifically, Brocaʼs area has been implicated in rule-based knowledge and also in syntactic violation detection. Rule-based knowledge or discriminating items based on structural similarities, has been shown in several neuroimaging studies that sought to determine the role of Brocaʼs area in artificial grammar learning.  In this study, during the acquisition of artificial grammar, Brocaʼs area was stimulated. Forty-four participants were recruited for the study. Transcranial direct current stimulation (tDCS), has been shown to increase cortical excitability and plasticity and has been also shown to alter motor learning. While an artificial language was being acquired, some participants were given the tDCS while the others were given sham stimulation. The participants were given a working memory task in order to demonstrate their performance during the acquisition phase. The performances of the groups were then compared. A classification task was then performed in which syntactic violations were detected. After tDCS , there was significant improvement in the areas where no cues to superficial similarity were present. This in turn resulted in better performance. It was also found that in an area unrelated to learning artificial grammar, the effects of tDCS on Broca’s area was supported also. Within this study, it was concluded that Broca’s area improves the particpants’ ability to detect syntactic violations.