tVNS Responsiveness Testing With Pupil Size

Exclusion Criteria

• •Able-bodied subjects:
• •Younger than 18 years old or older than 89 years old
• •Current or history of cardiac disease
• •Have a vision problem not corrected by glasses or contact lenses
• •Have an implanted device such as a neurostimulator or cochlear implant
• •Current or history of tympanic membrane perforation
• •Had a stroke or lesion (including tumor) in your brain
• •Had a head injury or brain surgery
• •Suffer from frequent or severe headaches
• •Had a fainting spell or syncope
• •Have any metal in the head such as shrapnel, surgical clips, or fragments from welding or metal work
• •Have any implanted device such as cardiac pacemakers, medical pumps, or intra-cardiac lines
• •Had any brain-related conditions (i.e. multiple sclerosis, Parkinson, Alzheimer)
• •Had any illness that caused brain injury (i.e. meningitis, aneurysm, brain tumor)
• •Had any head trauma that was associated with a loss of consciousness or diagnosed as a concussion
• •Being treated for any psychiatric condition (i.e. depression, anxiety, PTSD, schizophrenia)
• •Suspected of pregnancy
• •Post-stroke subjects:
• •Younger than 18 years old or older than 89 years old
• •Current or history of cardiac disease
• •Have a vision problem not corrected by glasses or contact lenses
• •Have any implanted devices such as a neurostimulator or cochlear implant
• •Current or history of tympanic membrane perforation
• •No persistent hemiparesis on the upper extremity (UE)
• •No residual UE voluntary movement
• •A first stroke less than 4 months prior to the participation
• •Serious uncontrolled medical conditions
• •Excessive pain in any joint of the more affected extremity
• •Unable to stand independently for 2 min., transfer independently to and from the toilet or perform sit-to-stand
• •Suffer from frequent or severe headaches
• •Had a fainting spell or syncope
• •Have any metal in the head such as shrapnel, surgical clips, or fragments from welding or metal work
• •Have any implanted device such as cardiac pacemakers, medical pumps, or intra-cardiac lines
• •Had any illness that caused brain injury (i.e. meningitis, aneurysm, brain tumor)
• •Had any head trauma that was associated with a loss of consciousness or diagnosed as a concussion
• •Being treated for any psychiatric condition (i.e. depression, anxiety, PTSD, schizophrenia)
• •Suspected of pregnancy
• •A score of less than 24 on the Folstein Mini-Mental State Examination
• •Excessive frailty or lack of stamina (e.g., cannot attend to instructions, stay awake, engage in functional activities, etc.)
• •Excessive pain in any joint of the more affected extremity that could limit ability to cooperate with the intervention