NCT07528378

Manipulating Social Percepts During fMRI

Manipulating Social Percepts With Real-Time fMRI

• Status: Not Yet Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 10 (estimated)
• Sponsor: Trustees of Dartmouth College · Academic / Other
• Sex: All
• Age: 18 Years – 35 Years
• Healthy volunteers: Accepted

Summary

This study will investigate the use of real-time fMRI to change how participants perceive social information.

Detailed description

The investigators have previously established stable individual differences in how people accumulate evidence for the presence and nature of a social interaction in visual displays, termed "social tuning curves". Taking individuals with deeply characterized neural and behavioral social tuning curves, this protocol will covertly manipulate percepts in two ways using real-time fMRI: 1) brain-state-triggered trials to bias participants toward a given percept based on their pre-stimulus brain state, and 2) implicit neurofeedback prior to and during stimulus exposure to teach participants to control their brain activity in social-perceptual circuits. These experiments will directly test causal relationships between activity at different levels of the cortical hierarchy and an individual's ultimate percept of a given social stimulus.

Conditions

• Healthy Volunteers

Interventions

Type	Name	Description
OTHER	Real-time fMRI: Brain-state- triggered trials	During each fMRI session, we will monitor subjects' brain activity in real time and use univariate and/or multivariate activity patterns to trigger trial presentation. For each individual, we will select three regions: one key region early in the cortical hierarchy (e.g., MT), one key region late in the cortical hierarchy (e.g., anterior temporal), and one control region that does not show strong tuning to social information (e.g., primary auditory). These regions will be functionally defined for each individual using data from their characterization sessions. Subjects will report percepts behaviorally after each trial. For each region for each individual, we will then test the correlation between pre-stimulus activity and the likelihood of reporting certain percepts across trials.
OTHER	Real-time fMRI: Covert neurofeedback	Neurofeedback is a type of biofeedback that uses real-time displays of brain activity in an attempt to teach subjects to self-regulate their brain function. Here we will use implicit neurofeedback, meaning that subjects will see a feedback signal, but will not be told what that feedback signal represents (i.e., which brain region) or what the expected effects of learning to control that brain region might be. This type of neurofeedback is less prone to suggestibility and other confounding effects. Each of the two scan sessions dedicated to this intervention will be split into four equal blocks in a 2x2 design with region (early or late) and direction of modulation (up or down). Subjects will see a continuous feedback signal representing the region and direction, and will be asked to try to modulate the signal using any strategy that occurs to them.

Timeline

• Start date: 2026-09-01
• Primary completion: 2027-05-01
• Completion: 2027-05-01
• First posted: 2026-04-14
• Last updated: 2026-04-14