Consequences of Prefrontal Brain Stimulation on Impulsivity – a Simultaneous tDCS-fMRI Study

Brain stimulation, vol. 14, pp. 1690

Abstract

Abstract Impulsivity is a hallmark of several psychiatric disorders, contributes to the likelihood of initial substance use, and is a strong predictor of relapse rates among patients with substance use disorder. In a previous study, a transcranial direct current stimulation (tDCS) protocol to improve response inhibition in a group of highly impulsive tobacco users and highly impulsive alcohol-dependent patients was established. Both groups showed increased response inhibition following anodal tDCS over the right dorsolateral prefrontal cortex (DLPFC), whereas no effects were seen in healthy controls. However, it remained unclear whether tobacco consumption (present also in alcohol-dependent patients) or impulsivity traits affected stimulation outcome. Further, it is not known whether behavioral changes were accompanied by changes in neural activity. Using a simultaneous high definition-tDCS-fMRI approach, the present project aims to identify neural correlates associated with improved response inhibition following anodal stimulation of the right DLPFC. Additionally, the project is designed to delineate the effects of trait impulsivity and nicotine intake on stimulation success by including groups of non-smoking healthy participants and chronic tobacco users with varying impulsivity traits. The experiment is designed in a double-blind, placebo-controlled manner and pre-registered at the german register for clinical studies. Participants are randomly allocated to either active or sham stimulation. Impulsivity is measured with the german version of the UPPS Impulsive behavior scale. An analysis of the behavioral data revealed an interaction of active tDCS with one of the UPPS subscales (urgency) on response inhibition. Interestingly, these effects were mainly driven by smoking individuals, pointing towards possible influences of tobacco and impulsivity on stimulation success. Keywords: HD-tDCS, Response Inhibition, MRI, Impulsivity

Authors 3

1. Dario Müller Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University Medical Faculty, Aachen, Germany

2. Carmen Weidler Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University Medical Faculty, Aachen, Germany

3. Ute Habel Aachen

   RWTH Aachen University · Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   Institute of Neuroscience and Medicine: JARA-Institute Brain Structure Function Relationship (INM 10), Research Center Jülich, Germany

   RWTH Aachen University Medical Faculty, Aachen, Germany