Effects of Orbitofrontal Cortex tDCS on Cognitive Control in Individuals With Obesity: A Randomized Sham-Controlled Trial.

OBJECTIVE

Neurocognitive traits can drive obesity-related eating behaviors. The orbitofrontal cortex (OFC) integrates reward and sensory information to guide food-related decision-making. Here, we build on prior data in individuals without obesity demonstrating that transcranial direct current stimulation (tDCS) of the OFC improves cognitive impulse control to test the effect of OFC tDCS in individuals with obesity.

METHODS

We use a single-blind, randomized, sham-controlled study among 60 adults with obesity to test whether either active (n = 30) or sham (n = 30) anodal tDCS targeting the left OFC specifically improves cognitive control using the Food and Word-Color Stroop tasks, the Iowa Gambling Task, and the Stop Signal Task.

RESULTS

Across all cognitive outcomes, active stimulation did not differ from sham. However, moderation analyses revealed that higher baseline food addiction symptoms were associated with poorer performance with tDCS on the high-calorie Food Stroop condition, whereas lower impulsivity, lower emotional eating, and higher cognitive restraint were associated with improved post-stimulation performance on the low-calorie Food Stroop condition.

CONCLUSIONS

Unlike what has been reported in lean individuals, a single session of OFC-targeted tDCS is insufficient to modify cognitive control in individuals with obesity. However, the cognitive effects of a single session of OFC stimulation depend on individual neurocognitive characteristics in obesity.

TRIAL REGISTRATION: ClinicalTrials.gov NCT04218383.