Modulating task-outcome value to mitigate real-world procrastination via noninvasive brain stimulation.

Procrastination is a prevalent behavioral problem associated with individual health and societal productivity. A leading model posits that procrastination reflects an imbalance between task aversiveness and the pursuit of positive task outcomes, yet this theoretical framework has neither been validated in real-world settings nor effectively applied to guide interventions. To address this gap, we conducted a double-blind, randomized, sham-controlled trial. Adults with chronic procrastination received seven sessions of high-definition transcranial direct current stimulation (HD-tDCS) to the left dorsolateral prefrontal cortex (DLPFC). Using the intensive experience sampling method, we assessed the effect of anodal HD-tDCS on real-world procrastination behavior at offline after-effect (2-day interval) and long-term after-effect (6-month follow-up). This neuromodulation produced a lasting reduction in real-world procrastination, with effects sustained at a 6-month follow-up. The mediation analysis indicated that increased outcome value, but not reduced task aversiveness, statistically accounted for variation in behavioral improvement. These findings are consistent with the hypothesis that enhancing DLPFC function may reduce procrastination by selectively amplifying the valuation of future rewards, not by reducing negative feelings about the task, which also suggests a targeted, theory-informed avenue for future behavioral interventions.