High‐definition transcranial direct current stimulation (HD‐tDCS) of left dorsolateral prefrontal cortex affects performance in Balloon Analogue Risk Task (BART)

Abstract

BackgroundStudies on risk preferences have long been of great concern and have examined the neural basis underlying risk‐based decision making. However, studies using conventional transcranial direct current stimulation (tDCS) revealed that bilateral stimulation could change risk propensity with limited evidence of precisely focalized unilateral high‐definition transcranial direct current stimulation (HD‐tDCS). The aim of this experiment was to investigate the effect of HD‐tDCS focalizing the left dorsal lateral prefrontal cortex (DLPFC) on risk‐taking behavior during the Balloon Analogue Risk Task (BART).MethodsThis study was designed as a between‐subject, single‐blind, sham‐controlled experiment. University students were randomly assigned to three groups: the anodal group (F3 anode, AF3, F1, F5, FC3 returned), the cathodal group (F3 cathodal, AF3, F1, F5, FC3 returned) and the sham group. Subsequently, 1.5‐mA 20‐min HD‐tDCS was applied during the BART, and the Positive Affect and Negative Affect Scale (PANAS), the Sensation Seeking Scale‐5 (SSS‐5), and the Behavioral Inhibition System and Behavioral Approach System scale (BIS/BAS) were measured as control variables.ResultsThe cathodal group earned less total money than the sham group, and no significant difference was observed between the anodal group and the sham group.ConclusionsThese results showed that, to some extent, focalized unilateral cathodal HD‐tDCS on left DLPFC could change performance during risky tasks and diminish risky decision making. Further studies are needed to investigate the dose effect and electrode distribution of HD‐tDCS during risky tasks and examine synchronous brain activity to show the neural basis.

Effects of transcranial direct current stimulation of prefrontal cortex on risk‐taking behavior

“…The random effect metaanalysis of eight synthetic trials revealed a significant ES supporting DLPFC electrical neuromodulation noninvasively, compared to sham TES in terms of reduction of risky behaviors and risk-taking propensity. Based on results of the subgroup analysis, the effect of tDCS is 19 Cheng and Lee (2016) 17 Russo et al (2017) 24 Russo et al (2017) 24 Russo et al (2017) 24 Guo et al (2018) 34 Nejati et al (2018) 23 Gilmore et al In other words, bilateral stimulation over the DLPFC showed no significant ES, whereas the unilateral DLPFC stimulation significantly affected risk-taking behavior. In fact, this type of stimulation results in lower scores of adjusted values (BART) and, therefore, a conservative risk-averse response style compared to sham tDCS.…”

“…49,50 These diverse results have also been reported in brain stimulation studies. Therefore, although it is difficult to conclude from these different results, both sides of the DLPFC appear to be involved, but not in a same way, in risk-taking behavior depending on the task and modality Cheng and Lee (2016) 17 Russo et al (2017) 24 Russo et al (2017) 24 Russo et al (2017) 24 Gilmore et al (2018) 20 Guo et al (2018) 34 Nejati et al (2018) 23Subtotal (I-squared = 0.0%, P = 0.643) Heterogeneity between groups: P = 0.275 Overall (I-squared = 80.6%, P = 0.000) Subtotal (I-squared = 89.6%, P = 0.000) Fig.3 Pooled estimate of standardized mean difference (SMD) for transcranial direct current stimulation effects on risk-taking behaviors after sub-grouping by unilateral or bilateral protocols, without those two outlier studies specified in Figure 2. CI, confidence interval.…”

“…Finally, 70 records were excluded during the full-text screening and data extraction, and 20 articles were evaluated as eligible studies: including 16 articles on tDCS, [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] two on tACS, 31, 32 one on tPCS, 33 and one on highdefinition tDCS. 34 One of these articles was open label 15 and the remaining 19 were randomized controlled trials. Among these 19 controlled trials, three used a within-subject design and the remaining 16 used a between-subject design.…”

“…Most included studies applied a single-session stimulation of 13-20 min when participants completed the BART. The effects of this short-lasting anodal and cathodal tDCS administration are primarily limited to changes in resting membrane Cheng and Lee (2016) 17 Russo et al (2017) 24 Russo et al (2017) 24 Russo et al (2017) 24 Guo et al (2018) 34 Gilmore et al (2018) 20 Nejati et al Pooled estimate of standardized mean difference (SMD) for transcranial direct current stimulation effects on risk-taking behaviors after sub-grouping by unilateral or bilateral protocols, without the outlier study in the bilateral subgroup. According to the results of publication bias analyses, the overall result obtained here was considered as the main overall result.…”

fMRI Informed Montage Selection for Transcranial Electrical Stimulation: Frontoparietal Synchronization for Drug Cue Reactivity

“…To find an appropriate location in the parietal lobe, in the first step, frontal regions were targeted. Typical high definition (HD) electrode set-ups utilize a 4x1 ring configuration were simulated, where four return electrodes over AF3, F1, F5, and FC3 surrounded the centered electrode over F3 [42,43]. After electrode placement, EFs were calculated based on the finite element method (FEM) using SimNIBS 3.2 software with a total current strength of 2 mA in the anode and 0.5 mA in each return electrode [44].…”