Effects of Transcranial Direct current Stimulation of Prefrontal Cortex on Risk-Taking Behavior.

AIM: Recent cognitive neuroscience researches show that noninvasive brain stimulation can modify a wide range of behaviors in healthy people. Such regulation effects on human behaviors provide new insights into the neurobiology of cognitive processes and establish causal brain-behavior relationships. Here, we aimed to examine the effects of transcranial electrical stimulation (TES) of prefrontal cortex on risk-taking. METHOD: We performed a systematic search on PubMed, Web of Science and Cochrane databases with appropriate keywords for original studies reporting the use of TES to modulate risk-taking behavior in healthy individuals. Then, in the meta-analysis phase, random-effects model was used to measure the pooled effect size. RESULTS: Twenty articles evaluated as eligible studies including 16 tDCS articles, two tACS articles, one tPCS article and one high-definition tDCS article. Meta-analysis showed a pooled estimated standardized effect size of -0.20 (CI:-0.39, -0.01) which indicates a small effect size for active tDCS over the DLPFC in comparison to sham stimulation (z = 2.31, P = 0.03) in terms of less risky behaviors. Subgroup analysis showed that there is no significant effect size for bilateral DLPFC stimulation (d = -0.01, CI:-0.28 to 0.26), but a significant near-medium effect size for unilateral DLPFC stimulation (d = -0.41, CI:-0.71 to -0.10). CONCLUSION: Our findings support a significant impact of neuroregulation of the DLPFC on risk-taking behavior in healthy individuals. Unilateral noninvasive electrical stimulation of the DLPFC can result in a conservative risk-averse response style, probably through modulating plasticity of the relevant brain networks including cortical and subcortical structures, as well as increasing subcortical dopaminergic activity. This article is protected by copyright. All rights reserved.