Neural Mechanisms of Interpersonal Expectations on Negative Affect Using Transcranial Temporal Interference Stimulation

What this Trial Is About

Researchers are studying whether a non-invasive brain stimulation method called transcranial temporal interference stimulation (tTIS) can reduce negative feelings, and how expectations shaped by care providers affect these results. The study aims to find out if active tTIS works better than sham (inactive) tTIS, and if positive treatment expectations improve the effects compared to negative ones. This research involves healthy adults aged 18 to 55 and uses a randomized, triple-blind design to explore these questions. The study has two experiments with different designs. Experiment 1 involves 30 participants who each complete four sessions combining active or sham tTIS with positive or negative placebo messaging. Active tTIS delivers specific electrical signals targeting the brain for 20 minutes, while sham tTIS mimics the procedure without effective stimulation. Experiment 2 includes 160 participants divided into patients and doctors; patients undergo two sessions with sham tTIS paired with either a social placebo intervention or no intervention, while doctors are trained to provide placebo messaging and monitor patient responses. Sessions are spaced at least 48 hours apart. Participants complete tasks that assess negative affect before and after each session, including cognitive effort, fear, and pain ratings. Physiological data such as heart rate, skin conductance, and others are recorded during the sessions. Additional assessments include MRI scans and behavioral measures. The study tracks changes in negative affect and physiological responses over approximately one month, with safety and tolerability monitored throughout.

Neural Mechanisms of Interpersonal Expectations on Negative Affect