Background: Understanding the mechanisms behind exerting self-control may reveal why health behaviors are resistant to change. Activity in the right inferior frontal gyrus (rIFG) plays a role in self-control processes and may be modulated using transcranial direct current stimulation (tDCS).
Objective: In this early phase behavioral research study, we investigated whether anodal stimulation over the rIFG with cathodal stimulation over the left IFG (versus sham) reduced chocolate consumption.
Methods: Twenty-three healthy females (ages 18-35) completed two tDCS sessions (2.0 mA vs. sham; order counterbalanced) in a within-subject, double-blind, randomized design with a 4-week washout. Participants were self-reported "chocolate cravers" and restrained eaters. Self-report assessments on disinhibited eating were completed at intake. Delay discounting and inhibitory control were assessed at the remaining visits. During stimulation, participants completed an inhibitory control training task (chocolate go/no-go task) and were randomized to the chocolate no-go condition (inhibit all responses to chocolate cues) or the control condition (inhibit responses to chocolate cues on half the trials). Following stimulation, participants completed a 15-min chocolate "taste test" with chocolate rating forms. Afterwards, staff measured the remaining chocolate to determine total consumption.
Results: Contrary to our hypotheses, active tDCS significantly increased chocolate consumption vs. sham (mean = 43.2 vs. 32.2, p=0.005) in both task conditions, but had no effect on chocolate ratings (ps > 0.05). Higher delay discounting and self-reported disinhibited eating predicted greater consumption (ps < 0.05).
Conclusions: The results suggest widespread activation of the prefrontal cortex may reduce the ability to resist chocolate. Our data highlights important methodological considerations for conducting tDCS studies to target health behaviors.
Keywords: Brain stimulation; Chocolate; Food intake; Inferior frontal gyrus; Inhibitory control.
Copyright © 2018. Published by Elsevier Ltd.