High-definition tDCS alters impulsivity in a baseline-dependent manner.
In intertemporal choice (ITC), people discount future rewards in proportion to the time delay until reward receipt. Despite recent non-invasive brain stimulation studies suggesting a general causal link between dorsolateral prefrontal cortex (dlPFC) activity and ITC impulsivity, results regarding the functional specificity of dlPFC are mixed. We used high-definition transcranial direct current stimulation (HD-tDCS) to map changes in causal impulsivity through bi-directional modulation of left and right dlPFC during ITC. Model-free and model-based analyses demonstrated that anodal and cathodal stimulation of left dlPFC, but not right dlPFC, decreased and increased impulsivity, respectively. Critically, an individual differences analysis revealed that modulation of impulsivity was contingent on participants' baseline impulsivity. Overall, our results might reconcile the discrepancies in the existing literature and suggest a baseline-dependent role for left dlPFC during ITC.
School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China; Center for Brain and Cognitive Sciences, Peking University, Beijing 100871, China.
Bo
B
Shen
School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China.
Yunlu
Y
Yin
School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China.
Jiashu
J
Wang
School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China; Center for Brain and Cognitive Sciences, Peking University, Beijing 100871, China; Key Laboratory of Machine Perception (Ministry of Education), Peking University, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China.
Xiaolin
X
Zhou
Department of Psychology, Arizona State University, Tempe, AZ 85287, United States.
Samuel M
SM
McClure
School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China. Electronic address: li.jian@pku.edu.cn.
Jian
J
Li
D000328:Adult; D065786:Delay Discounting / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000502:physiology*; D008297:Male; D017397:Prefrontal Cortex / Q000502:physiology*; D065908:Transcranial Direct Current Stimulation / Q000379:methods*; D055815:Young Adult
Delay discounting; Dorsolateral prefrontal cortex; HD-tDCS; Intertemporal choice