Task-specific effects of tDCS-induced cortical excitability changes on cognitive and motor sequence set shifting performance

• Published in: PloS one Vol. 6; no. 9; p. e24140
• Main Authors: Leite, Jorge, Carvalho, Sandra, Fregni, Felipe, Gonçalves, Óscar F
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01-09-2011; Public Library of Science (PLoS)
• Subjects: Analysis; Artificial neural networks; Biology; Cognition - physiology; Cognitive ability; Cognitive tasks; Cortex (motor); Direct current; Dopamine; Electric Stimulation; Electrical stimulation of the brain; ESB; Excitability; Filtration; Humans; Laboratories; Medicine; Motor Cortex - physiology; Motor task performance; Neural networks; Prefrontal cortex; Prefrontal Cortex - physiology; Reaction Time - physiology; Social and Behavioral Sciences; Stimulation; Task analysis; Task Performance and Analysis; Tomography; Transcranial magnetic stimulation
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0024140

In this study, we tested the effects of transcranial Direct Current Stimulation (tDCS) on two set shifting tasks. Set shifting ability is defined as the capacity to switch between mental sets or actions and requires the activation of a distributed neural network. Thirty healthy subjects (fifteen per site) received anodal, cathodal and sham stimulation of the dorsolateral prefrontal cortex (DLPFC) or the primary motor cortex (M1). We measured set shifting in both cognitive and motor tasks. The results show that both anodal and cathodal single session tDCS can modulate cognitive and motor tasks. However, an interaction was found between task and type of stimulation as anodal tDCS of DLPFC and M1 was found to increase performance in the cognitive task, while cathodal tDCS of DLPFC and M1 had the opposite effect on the motor task. Additionally, tDCS effects seem to be most evident on the speed of changing sets, rather than on reducing the number of errors or increasing the efficacy of irrelevant set filtering.