Neural Noise- Anodal tDCS over right ventrolateral prefrontal cortex enhances rational decision-making in a controlled study.1
- The result suggests targeted cognitive enhancement via tDCS in decision-making circuits.1 1
Weekly enrichment (2026-07-20)
- The study (Scientific Reports, 2025) tested whether anodal tDCS over the right ventrolateral prefrontal cortex (rVLPFC, mapped to the F8 site of the 10–20 EEG system) increases “rational,” self-interested choices in the ultimatum game; 61 first-year psychology students at Bar-Ilan University participated (78% women, mean age 22.5, SD 1.73), randomly assigned to anodal (n=30) or sham (n=31).2
- Stimulation delivered a constant 1.5 mA for 20 minutes via a battery-driven NeuroConn/Eldith stimulator, using a small 3×3 cm anode (9 cm², current density 0.166 mA/cm²) over rVLPFC and a larger 5×7 cm reference cathode (35 cm², 0.04 mA/cm²) over the contralateral supraorbital area; the ROAST MATLAB toolbox modeled current flow on a realistic head model.2
- Sham used a 30 s ramp-up to 1.5 mA, a brief 30 s of stimulation, then a 30 s ramp-down — an established blinding technique that reproduces scalp sensation without lasting cortical excitability change.2
- Anodal stimulation raised acceptance of unfair offers to 72.2% versus 61.3% under sham (p=.044), moving behavior closer to the standard economic (self-interest) model.2
- Well-documented control effects were replicated: acceptance fell as offers became more unfair, F(4,236)=92.52, p<.001, ηp²=0.61, and computer offers were accepted more than human-partner offers, F(1,59)=14.59, p<.001, ηp²=0.20.2
- The effect was behaviorally specific: it appeared when participants played for their own payoff but was absent when they decided on behalf of another random individual, and did not depend on whether the offer came from a human or a computer.2
- Sample size was fixed a priori by a power analysis (MorePower 6.0): a meta-analytic effect of ηp²=0.10 yielded 99% power at α=0.05 with 60 participants, the target the authors recruited to.2
- The authors interpret the rVLPFC as a cognitive-control/emotion-regulation hub and contrast it with the right dorsolateral PFC (rDLPFC), whose anodal stimulation instead decreases acceptance of unfair offers, implying complementary lateral-prefrontal roles in arbitrating self-interest versus fairness.23
- Related prefrontal-tDCS work shows neuromodulation can shift economic decision biases more broadly — excitatory (1.5 mA) stimulation of the ventromedial PFC reduced gambling/framing biases via improved feedback learning — supporting tDCS as a tool for probing and nudging decision circuits.4
- Note: the manifest source (ScienceDirect / Brain Stimulation) could not be fetched, so this enrichment draws device and protocol details from the closely matching primary report in Scientific Reports and its preprint (fallback sources).12