Subcortical Arousal in Perceptual Awareness

Conditions

• Epilepsy

Eligibility Criteria

Sex

ALL

Age

13 Years - N/A

Healthy Volunteers

Not accepted

Interventions

• EEG — DEVICE
  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 — DEVICE
  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 — DEVICE
  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 — DIAGNOSTIC_TEST
  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.

Study Details

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.

Key Dates

Start date

Oct 13, 2025

Status verified

Jun 2026

Primary completion

Dec 31, 2030

Completion

Dec 31, 2030

Study Design

Enrollment

202 participants (estimated)

Allocation

NON_RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

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.

Primary Outcome Measure

Subcortical event-related signals [ Time Frame: Immediately after the intervention ]

Central Contacts

• Hal Blumenfeld, MD, PHD
  (203) 785-3865
  [email protected]
• Kristine Dacosta
  [email protected]

Locations (8)

Find similar trials in New Haven, CT

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