title: Diminishing risk-taking behavior by modulating activity in the prefrontal cortex: a direct current stimulation study.
abstract: Studies have shown increased risk taking in healthy individuals after low-frequency repetitive transcranial magnetic stimulation, known to transiently suppress cortical excitability, over the right dorsolateral prefrontal cortex (DLPFC). It appears, therefore, plausible that differential modulation of DLPFC activity, increasing the right while decreasing the left, might lead to decreased risk taking, which could hold clinical relevance as excessively risky decision making is observed in clinical populations leading to deleterious consequences. The goal of the present study was to investigate whether risk-taking behaviors could be decreased using concurrent anodal transcranial direct current stimulation (tDCS) of the right DLPFC, which allows upregulation of brain activity, with cathodal tDCS of the left DLPCF, which downregulates activity. Thirty-six healthy volunteers performed the risk task while they received either anodal over the right with cathodal over the left DLPFC, anodal over the left with cathodal over the right DLPFC, or sham stimulation. We hypothesized that right anodal/left cathodal would decrease risk-taking behavior compared with left anodal/right cathodal or sham stimulation. As predicted, during right anodal/left cathodal stimulation over the DLPFC, participants chose more often the safe prospect compared with the other groups. Moreover, these participants appeared to be insensitive to the reward associated with the prospects. These findings support the notion that the interhemispheric balance of activity across the DLPFCs is critical in decision-making behaviors. Most importantly, the observed suppression of risky behaviors suggests that populations with boundless risk-taking behaviors leading to negative real-life consequences, such as individuals with addiction, might benefit from such neuromodulation-based approaches.
authors.affiliation: Berenson-Allen Center for Noninvasive Brain Stimulation, Harvard Medical School, Boston, Massachusetts 02215, USA.
authors.forename: Shirley
authors.initials: S
authors.lastname: Fecteau
authors.forename: Daria
authors.initials: D
authors.lastname: Knoch
authors.forename: Felipe
authors.initials: F
authors.lastname: Fregni
authors.forename: Natasha
authors.initials: N
authors.lastname: Sultani
authors.forename: Paulo
authors.initials: P
authors.lastname: Boggio
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pascual-Leone
mesh_terms: D000328:Adult; D001519:Behavior / Q000502:physiology*; D003337:Corpus Callosum / Q000502:physiology; D003657:Decision Making / Q000502:physiology; D004558:Electric Stimulation / Q000009:adverse effects; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007600:Judgment / Q000502:physiology*; D008297:Male; D001523:Mental Disorders / Q000503:physiopathology; D009433:Neural Inhibition / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology*; D012201:Reward; D012309:Risk-Taking