Epilepsy
Conditions
Brief summary
The study is a multi-site study and will be conducted at up to 11 investigative sites in the United States. The study will investigate subcortical arousal circuits in visual perception using techniques with complementary strengths based on promising initial studies.
Detailed description
The study will investigate subcortical arousal circuits in visual perception using techniques with complementary strengths based on promising initial studies. This study is expected to shed important light on the precise relationship between transient increases in subcortical arousal and perceptual awareness, generalizable across the visual modality. This research will therefore provide important general potential benefits, including 1. Identification of subcortical arousal systems in perception, which can benefit treatment of many disorders where perceptual deficits are common, e.g. traumatic brain injury, Alzheimer's disease, stroke, developmental disorders, schizophrenia, epilepsy and others. 2. Understanding the role of specific subcortical arousal circuits in perception may help target improved treatments, including transient thalamic stimulation like that planned for the present investigations, or less invasive treatments (TMS, tDCS, designer drugs) to improve function of these circuits. 3. The planned no-report paradigms may detect perceptual awareness in severe brain damage and anesthesia, where people are unable to overtly respond. The main hypotheses are that 1. the thalamic awareness potential (TAP) will be associated with visual perception independent of report, and 2. thalamic intralaminar stimulation at the time of stimulus presentation will augment the probability of perceptual awareness.
Interventions
DEVICEEEG
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
DEVICEEye 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
DEVICEBehavioral 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.
Sponsors
Yale University
National Institute of Neurological Disorders and Stroke (NINDS)
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
13 Years to No maximum
Healthy volunteers
No
Inclusion criteria
The following are the inclusion/
Exclusion criteria
for epilepsy patients with thalamic electrodes age 13 years and up (Aim 1): Inclusion Criteria: * normal vision with or without the use of corrective lenses
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Subcortical event-related signals | Immediately after the intervention | 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 | Immediately after the intervention | measured by the percentage of correctly perceived trials for each participant (Aim 2) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cortical Event Related Potentials | Immediately after the intervention | Cortical event related potentials will be measured by scalp EEG to assess brain wave changes at the surface level during the perceptual awareness task |
Countries
United States
Contacts
CONTACTHal Blumenfeld, MD, PHD
CONTACTKristine Dacosta
PRINCIPAL_INVESTIGATORHal Blumenfeld, MD, Phd
Yale University
Outcome results
None listed