Recruiting

Observational Study

Sponsor:

Yale University

Code:

NCT06934356

Conditions

Epilepsy

Eligibility Criteria

Sex: All

Age: 13+

Healthy Volunteers: Not accepted

Interventions

EEG

Eye Tracking

Behavioral task

fMRI

Study Details

Brief summary:

The study consists of prospective enrollment of healthy participants and patients with epilepsy, as well as analysis of an existing data set. Healthy participants will be studied with fMRI, eye metrics and behavioral testing at Yale. Patients will be studied with intracranial thalamic and cortical recording and stimulation, eye metrics and behavioral testing.

Conditions

Epilepsy

Study ID

NCT06934356

Start date

Oct 13, 2025

Status verified date

Aug, 2026

Completion date

Dec, 2030

Anticipated

Primary completion date

Dec, 2030

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 13+

Healthy Volunteers: Not accepted

A. The following are the inclusion/exclusion criteria for healthy participants age 18 years and up (Aim 1 and 2):

Inclusion: (1) normal vision with or without the use of corrective lenses; (2) normal hearing not needing an assistive hearing device.

Exclusion: (1) past history of diagnosis of a psychiatric or neurologic disease; (2) current psychiatric or neurologic disease; (3) requires hard contact lenses or glasses to maintain normal vision (prevents accurate pupil and eye gaze measurements); (4) pregnant or nonremovable ferrous metal objects inside or on the body (prevents MRI).

B. The following are the inclusion/exclusion criteria for epilepsy patients with thalamic electrodes age 13 years and up (Aim 3A):

Inclusion: (1) normal vision with or without the use of corrective lenses

Exclusion: (1) severe vision impairment even with correction preventing ability to see stimuli (prevents accurate pupil and eye gaze measurements); (2) unable to perform the perception task due to cognitive impairment. All participants must be capable of consenting for themselves.

C. The following are the inclusion/exclusion criteria for epilepsy patients with thalamic electrodes age 18 year and up (Aim 3B):

Inclusion: (1) normal vision with or without the use of corrective lenses; (2) A female subject must have a negative pregnancy test and if sexually active, must be using a reliable form of birth control for the duration of the trial, be surgically sterile, or be at least two years post-menopausal.

Exclusion: (1) severe vision impairment even with correction preventing ability to see stimuli (prevents accurate pupil and eye gaze measurements); (2) unable to perform the perception task due to cognitive impairment. All participants must be capable of consenting for themselves; (3) Pregnancy.

Study Design

Enrollment

202 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Intracranial Thalamic and Cortical Recording (Aim 3A)

Participants will perform the visual behavioral task with intracranial electroencephalogram (EEG) brain recordings carried out in parallel with surface EEG recordings. For Aim 3A, we will analyze thalamic event related potentials in perceived vs not perceived stimuli, classified as in perception of no report visual stimuli based on eye metrics.

experimental: Thalamic Stimulation (Aim 3B)

We will test participants during the Visual Report Paradigm, while recording from the intralaminar thalamus with simultaneous scalp EEG as in Aim 3A. Three thalamic stimulation conditions will be tested, randomized across trials: 1. No stimulation; 2. Stimulation Concurrent with visual stimuli; 3. Stimulation Delayed to 2s after visual stimuli. Stimulation will be a 100Hz train lasting 300ms, with biphasic square wave pulses 120μs per phase, current adjusted previously by clinicians to maximum tolerated level without side effects (typically \~3mA).

The electrical stimulation is being delivered for research purposes to understand the causal role of thalamus in regulating visual perception.

experimental: fMRI with report + no-report perception paradigms (Aims 1 and 2)

Participants will consist of healthy adults undergoing fMRI, eye metric and behavioral testing with report + no-report perception paradigms. This will include prospective data collection for the auditory paradigm, tactile paradigm, as well as analysis of an existing data set for the visual paradigm.

Interventions

EEG

Participants will have scalp EEG recorded with the international 10-20 system sampled at 256Hz using EEG amplifiers for purposes of surface event related potential analysis

Eye Tracking

An eye-tracking device may be used during the perceptual awareness task. Pupillary and gaze location measurements are recorded using either a ViewPoint\~VoltagePro.EyeLink 1000 Plus system, or Argus Science ETVision system. If using the ViewPoint\~VoltagePro system or the Argus Science ETVision system, participants will be asked to wear an eye tracker during the perceptual awareness task (similar to wearing sunglasses). If using the EyeLink 1000 Plus system, participants may be asked to place their head inside of a padded head-chin rest to stabilize head position

Behavioral task

For the visual perceptual awareness task, the participant will be presented with barely perceptible visual stimuli. After a variable delay, the participant will be asked to report perception of each stimulus and identify its location.

fMRI

Visual, auditory or tactile behavioral task will be performed during fMRI at the Yale MR Center. The subject will be asked to lie still in a 3T magnet scanner for up to 15-minute blocks. Each subject will have a sagittal T1-weighted localizer scan (3 minutes) and axial-oblique T1-weighted images (3 min). Multiple 5-15-minute imaging runs will be repeated up to 10 times. The subjects' responses will be recorded by a computer that is linked to the button box. The stimuli will be presented in blocks of 5 to 15 minutes throughout the MR imaging sequences.

Primary outcome measure

  • Subcortical event-related signals [ Time Frame: Immediately after the intervention ]
  • Perceptual Sensitivity [ Time Frame: Immediately after the intervention ]
  • Activity changes [ Time Frame: Immediately after the intervention ]
  • Functional connectivity [ Time Frame: Immediately after the intervention ]

Central Contacts and Locations

Central contacts

Hal Blumenfeld, MD, PHD

(203) 785-3865Hal.blumenfeld@yale.edu

Kristine Dacosta

kristine.dacosta@yale.edu

Locations

Yale School of Medicine

Recruiting

New Haven, Connecticut, United States, 06520

Contacts

Francois Stockart

francois.stockart@yale.edu

Principal Investigator:

Hal Blumenfeld, MD, PhD

University of Kansas Medical Center

Recruiting

Kansas City, Kansas, United States, 66160

Contacts

Laura Crabtree

lcrabtree2@kumc.edu

Principal Investigator:

Utku Uysal, MD, MS

Massachusetts General Hospital

Recruiting

Boston, Massachusetts, United States, 02114

Contacts

Erin Kaye Donahue, PhD

ekdonahue@mgh.harvard.edu

Principal Investigator:

Mark Richardson, MD, PhD

Mayo Clinic

Recruiting

Rochester, Minnesota, United States, 55901

Contacts

Ana Sanchez

sanchez.ana2@mayo.edu

Principal Investigator:

Jamie Van Gompel, MD

Dartmouth Hitchcock Medical Center

Recruiting

Lebanon, New Hampshire, United States, 03756

Contacts

Anastasia Kanishcheva, MPH

anastasia.kanishcheva@hitchcock.org

Principal Investigator:

Barbara Jobst, MD

Vanderbilt University Medical Center

Recruiting

Nashville, Tennessee, United States, 37235

Contacts

Kayla James

kayla.s.james@vumc.org

Ella Provancher

ella.provancher@vumc.org

Principal Investigator:

Dario Englot, MD, PhD

Baylor College of Medicine

Recruiting

Houston, Texas, United States, 77030

Contacts

Victoria Gates

victoria.gates@bcm.edu

Principal Investigator:

Sameer Anil Sheth, MD, PhD

More Information

Sponsor

Yale University

Last update posted

Aug 10, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Yale University on 2026-08-10.