Clinical trial NCT06975800: Effects of Social Feedback on Intracranial EEG
Official title: Effects of Social Feedback on Intracranial EEG
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Social Influence
Epilepsy
Lead sponsor: Trustees of Dartmouth College
Sponsor class: OTHER
First posted: 2025-05-16
Enrollment: 24
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Patients will watch videos of several doctors. Doctor videos will be presented that increase or decrease expected negative affect (the intervention) in a within-person crossover design.

Patients will then perform a doctor rating task (reporting on their impressions of warmth, competence, and similar traits associated with care competency).

Trial blocks consist of a brief video of one of the 8 doctors previously rated by the participant. The doctor will explain what to expect on the upcoming Multimodal Negative Affect Task (MNAT) trials, followed by 4 task trials (fear or math, see Protection of Human Subjects for additional MNAT information). Video cues will include 4 threat-suggestion and 4 safety-suggestion videos for each doctor (8 doctors X 2 low/high threat cues X 3 repetitions x 4 trials per block, 144 total trials).
Primary purpose: BASIC_SCIENCE

Brief summary: This study aims to assess the impact of social influence on direct neural recordings in human patients undergoing surgical treatment of epilepsy. 24 patients recruited from the Epilepsy Center at Dartmouth Health Medical Center (DHMC) will undergo electrode implantation throughout the brain to localize epileptogenic zones. Patients will be asked to rate their provider's warmth, competence, and other, similar traits associated with care-competency. They will then complete the picture-induced fear and math portions of the multimodal negative affect task (MNAT) during which iEEG is recorded.

Detailed description: This study aims to assess the impact of social influence on direct neural recordings in human patients undergoing surgical treatment of epilepsy. A total of 24 patients, ranging in age from 18 to 65 years, will be recruited from the Epilepsy Center at Dartmouth Health Medical Center (DHMC), which serves a catchment area of approximately 2.5 million people in Northern New England. Patients eligible for intracranial electroencephalography (iEEG) are determined by a clinical-based multidisciplinary board, with 10-20 iEEG studies performed annually in the Epilepsy Monitoring Unit.

Each patient will undergo electrode implantation throughout the brain to localize epileptogenic zones, with 12-20 electrode leads implanted, each containing 8-18 channels. This results in a total of 150 to 220 channels of continuous electrophysiological data per patient. The iEEG signals will be recorded using a Natus clinical system, and precise timing synchronization will be ensured between the iEEG recordings and the experimental paradigm presentation.

The protocol will involve a single one-hour session for each patient. Patients will participate in a doctor rating task, where they provide impressions of warmth, competence, and other qualities related to the doctors presented in the experiment. Additionally, patients will perform a simplified version of the Multimodal Negative Affect Task (MNAT) used in Experiment 2, with the omission of pain stimuli to increase patient acceptability and reduce time and fatigue burden. Trial blocks will consist of brief videos of the doctors explaining what to expect in the upcoming trials, followed by four task trials involving fear or math stimuli from the MNAT task. Each doctor will have four threat-suggestion videos and four safety-suggestion videos, resulting in a total of 144 trials (8 doctors X 2 low/high threat cues X 3 repetitions x 4 trials per block).

The analysis of the neural data will involve time-frequency decomposition of local field potentials (LFPs) to examine broadband gamma-frequency power (40-200 Hz) locked to cue and stimulus onset time. Effects of cues (high vs. low-expectancy), self-reported fear or effort within each cue condition, and their interaction on broadband gamma signals will be assessed for each electrode contact. A focus will be placed on affect-encoding electrodes showing relationships with fear and/or effort within conditions. Proportions of affect-encoding electrodes and other contacts demonstrating social influence effects will be quantified. The analysis will also explore assimilation and contrast effects with cue-predicted values, investigating whether social information influences the neural correlates of affective experience.

To ensure appropriate sample size, it is anticipated that 10-15 eligible patients will participate each year during the project period. Biological sex differences and age will be controlled for in all analyses, and hypotheses will be tested while considering these factors. The study aims to provide valuable insights into the effects of social influence on neural activity, expanding our understanding of the mechanisms underlying placebo effects and affective experiences.

Eligibility criteria: Inclusion Criteria:

* Patients must be between 18-65 years of age.
* Patients must have a diagnosis of refractory epilepsy undergoing intracranial EEG recording for clinical purposes.
* Patients with a legal guardian will be considered for participation if they are interested and, in the judgment of the research team, they are capable of performing the cognitive tasks required of the study. In those instances, the patient and their legal guardian will both participate in the informed consent process, with the legal guardian signing the consent form.

Exclusion Criteria:

* Patient has additional neurological condition (such as stroke or dementia) or a psychiatric condition (such as active psychosis or suicidal ideation) and are deemed inappropriate for the study.
* Patients are not able to provide informed consent for any reason (e.g. encephalopathic, experiencing a seizure).

Primary outcomes:
measure: Negative affect ratings
timeFrame: Ratings are made 3 to 10 seconds after experiencing each stimulus presented during task performance.
measure: Cognitive effort ratings
timeFrame: Ratings are made 3 to 10 seconds after experiencing each stimulus presented during task performance.
Secondary outcomes:
measure: Intracranial neural responses to math problems and aversive fear-related images in the amygdala
timeFrame: Continuous recording during task performance, duration 1 hour
Other outcomes:
Locations:
city: Lebanon
country: United States
facility: Dartmouth Hitchcock Medical Center
state: New Hampshire
Study officials:
References: