About this trial
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.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
None
Disqualifiers
None
Trial design
Parallel
Treatments tested in this trial
EEG
DeviceParticipants 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
DeviceAn 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
DeviceFor 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 testVisual, 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.
Treatment groups
Trial outcomes
Primary outcomes
Subcortical event-related signals
Subcortical event-related signals will be recorded by icEEG to assess electrical activity from the cerebral cortex using currently implanted electrodes during the behavioral task
Perceptual Sensitivity
measured by the percentage of correctly perceived trials for each participant (Aim 3B)
Activity changes
Measured using functional magnetic resonance imaging (fMRI) during task onset and off-set to fixation and compare them to fMRI changes during conscious perception of a stimulus vs. not-reported stimuli (Aims 1 and 2)
Functional connectivity
Measured using fMRI to establish networks actively engaged during task vs. fixation and consciously-reported vs. not-reported stimuli (Aims 1 and 2).
Secondary outcomes
Cortical Event Related Potentials
Cortical event related potentials will be measured by scalp EEG to assess brain wave changes at the surface level during the perceptual awareness task
Sponsors and contacts
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Yale University
Lead sponsor
National Institute of Neurological Disorders and Stroke (NINDS)
Collaborator