MRI-tDCS Stress and Future Thinking Study

Overview

This academic study investigates how MRI-compatible transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) influences stress regulation and episodic future thinking in healthy volunteers. Participants undergo one MRI session: combining stress induction, tDCS (real or sham), and functional and metabolic MRI measurements. The study aims to better understand how non-invasive brain stimulation affects the neurophysiological and psychological mechanisms involved in stress processing and future-oriented thinking.

The purpose of this study is to examine the modulatory effects of non-invasive brain stimulation on cognitive and emotional processes related to stress regulation and episodic future thinking (EFT). Healthy adult volunteers complete one MRI session. Participants were randomly assigned to active or sham stimulation. First, participants performed an fMRI-based baseline measurement of the EFT task. This task involves imagining specific future personal events in response to cue words presented on a screen and later verbally describing these imagined events outside the scanner. During the second part, participants complete the Montreal Imaging Stress Task (MIST) - a mental arithmetic paradigm with time pressure and negative feedback to induce acute stress. Immediately afterward, they receive MRI-compatible tDCS (active or sham) for 20 minutes while at rest. The active tDCS delivers 2 mA current through a 4×4 cm anode placed over the left DLPFC and a cathode over the contralateral orbitofrontal region. Sham stimulation follows the same setup with current ramping only at the onset and offset. Following stimulation, an ASL perfusion scan, MRS spectroscopy targeting the hippocampus, and a post-stimulation EFT fMRI task were conducted. Throughout the MRI scan, behavioral and psychometric data were collected, including questionnaires on rumination, personality, and mood, as well as physiological and biochemical measures such as salivary cortisol and heart rate variability (HRV). The primary goal is to assess whether active tDCS modulates the neural, endocrine, and behavioral correlates of stress and future-oriented cognition compared to sham stimulation.

Conditions

Interventions

Eligibility

Locations (1)

Outcomes