Transcranial direct current stimulation (tDCS) over the orbitofrontal cortex reduces delay discounting

Abstract

Delay discounting (DD) is a quantifiable psychological phenomenon that regulates decision-making. Nevertheless, the neural substrates of DD and its relationship with other cognitive domains are not well understood. The orbitofrontal cortex (OFC) is a potential candidate for supporting the expression of DD, but due to its wide involvement in several psychological functions and neural networks, its central role remains elusive. In this study, healthy subjects underwent transcranial direct current stimulation (tDCS) while performing an intertemporal choice task for the quantification of DD and a working memory task. To selectively engage the OFC, two electrode configurations have been tested, namely, anodal Fp1–cathodal Fp2 and cathodal Fp1–anodal Fp2. Our results show that stimulation of the OFC reduces DD, independently from electrode configuration. In addition, no relationship was found between DD measures and either working memory performance or baseline impulsivity assessed through established tests. Our work will direct future investigations aimed at unveiling the specific neural mechanisms underlying the involvement of the OFC in DD, and at testing the efficacy of OFC tDCS in reducing DD in psychological conditions where this phenomenon has been strongly implicated, such as addiction and eating disorders.

Neural correlates of metacognition: Disentangling the brain circuits underlying prospective and retrospective second‐order judgments through noninvasive brain stimulation

“…Starting from our results, future investigations could also focus on assessing the role of metacognition in influencing other cognitive functions. In this research framework, delay discounting, that is, an element underlying decision‐making (Moro, Saccenti, Ferro, et al., 2023), represents a perfect candidate given the possibility of testing such process either invasively in rodents via open‐source behavioral apparatus (Moro, Saccenti, Seccia, et al., 2023) or noninvasively among humans through tDCS (Moro, Saccenti, Vergallito, et al., 2023). Further investigations are therefore needed to fill these gaps and elucidate the phenomenon of thinking about thinking.…”

Novel Approaches for the Treatment of Post-Traumatic Stress Disorder: A Systematic Review of Non-Invasive Brain Stimulation Interventions and Insights from Clinical Trials

“…Further research could also explore whether NIBS-induced effects on PTSD also concern the higher-order cognitive processes of traumatized patients and if an eventual improvement correlates with PTSD symptoms’ severity. Among higher-order cognitive functions, delay discounting might represent a strategic candidate [ 130 ] since it is a transdiagnostic marker sensible to NIBS intervention that can be assessed through intertemporal choice tasks in both human subjects and animal models [ 131 , 132 ]. Another prompt for further investigations involves latent profile analysis [ 133 ], which would be a useful tool for identifying subgroups of patients with PTSD on which an integrated treatment could be suggested a priori or also turn out to be more effective in terms of symptoms’ mitigation.…”

White matter-based brain network topological properties associated with individual impulsivity

“…Cold EFs, on the other hand, involve purely cognitive information processing (e.g., response inhibition and working memory) and are mainly associated with the lateral prefrontal cortex including dorsolateral prefrontal cortex (DLPFC) and ventrolateral prefrontal cortex 89 , 90 . In the present study, the DLPFC and OFC, which are involved in the DD 91 , 92 , were not included in the hubs identified through GTA. Considering that the present study used the structural connectivity network, the hub would be an area with many direct connections (i.e., fibers) between brain regions.…”

“…Many previous studies have investigated the effect of neuromodulation on impulsivity by TMS and tDCS 37 , 93 . Especially, the vast majority of neuromodulation studies in DD have targeted the DLPFC, OFC, ventromedial prefrontal cortex, and temporoparietal junction, but the results of these studies are inconsistent (e.g., either increases or decreases in DD 37 , 92 ). The regions (the left SFGmed and right precentral gyrus) identified in the present study may be proposed as potential targets for neuromodulation of impulsivity.…”