Inclusion Criteria:
* Inclusion Criteria (for healthy young adults in fMRI studies)
1. Able to provide verbal and written informed consent
2. Fluent English speaker
3. At least 8th grade education
4. Age between 18-40 years.
5. Normal or corrected-to-normal eyesight
Exclusion Criteria (for healthy young adults in fMRI studies)
1. Magnetic resonance imaging contraindications (e.g., metallic objects in body, claustrophobia)
2. Current use of anticonvulsant, neuroleptic, sedatives, or other medications known to affect cognition
3. Neurologic conditions affecting the brain (e.g., stroke, epilepsy, traumatic brain injury with loss of consciousness)
4. Psychiatric conditions (e.g., major depression, schizophrenia)
Patient inclusion criteria for iEEG:
Inclusion Criteria:
1\. Adult patients with medically refractory epilepsy who are scheduled to undergo or have previously undergone placement of sub-dural electrodes or depth electrodes or stereo-electroencephalography to localize the site of seizure onset.
Exclusion Criteria:
1. Patients with gross structural abnormalities (hematoma, tumors, large vascular malformations, diffuse malformations of cortical development) that may impact critical perceptual or memory areas needed to perform tasks.
2. Patients who are unable to participate in memory testing due to impaired cognition or mental retardation. All patients routinely undergo a detailed neuropsychological evaluation, and the neuropsychological report will be used to make this assessment.
3. Patients/volunteers with cardiac pacemakers, intracranial aneurysm clips, or other potentially mobile implanted metallic devices cannot be included in this study, because of possible effects of high power magnetic fields on them.
4. Patients with claustrophobia who cannot undergo an MRI scan without sedation.
5. Pregnant women
Patient inclusion criteria for scopolamine:
1. In good general health, aside from a history of epilepsy, as ascertained by medical history, physical examination (PE), clinical laboratory evaluations, and ECG.
2. Body mass index between 18-35 kg/m2.
Patient exclusion criteria:
1. History of renal insufficiency.
2. Patients with liver failure.
3. Patients with autoimmune neuropathy.
4. Patients with uncontrolled hyperthyroidism.
5. Patients with a history of dementia.
6. Patient with a history of delirium after using transdermal scopolamine.
7. History of narrow-angle glaucoma (due to increased eye pressure).
8. History of pyloric obstruction or paralytic ileus.
9. History of myasthenia gravis, obstructive uropathy, porphyria, or myasthenia gravis.
Exclusion Criteria:
\-
