This project will utilize a home-operated stimulator in 1) a healthy young adult population and 2) a healthy older adult population to provide a proof of concept of home-use of transcutaneous vagal nerve stimulation (tVNS). tVNS is believed to modulate cognitive performance.

The vagal nerve is a major component of the autonomic nervous system and mediates the physiological responses of major organs during moments of stress and learning, including brain areas that modulate cognitive performance. Vagal nerve stimulation (VNS) has been indicated to improve stress response and to enhance neuroplasticity by directly impacting brain structures critical for cognition. Historically, VNS methods required neurosurgery and were reserved for medically intractable epilepsy or other severe conditions. Today, vagal nerve stimulation can be performed with a minimal-risk non-invasive approach without surgery through a technique called transcutaneous Vagal Nerve Stimulation (tVNS). This project will utilize a home-operated stimulator in healthy young adult and healthy older populations to provide a proof of concept of practical home-use stimulation.

Inclusion Criteria:

• Participants for one cohort will be adults between the ages of 18-55, consistent with the typical college population
• Participants for the other cohort will be adults between the ages of 56 - 85. Participants must read and write English.

Exclusion Criteria:

• Major medical illnesses including diagnosed severe neurological illnesses (e.g., stroke, seizure history), autoimmune disorders, and severe psychiatric diseases (e.g., schizophrenia) will be excluded. Participants with any history of brain surgery, tumor, intracranial metal implantation, pacemakers or other implanted devices will be excluded.
• Sleep medications and/or psychostimulants are exclusionary. Subjects in the older cohort will NOT be excluded for taking blood pressure and cholesterol medication. Participants who are pregnant will be excluded. If participants have a history of adverse reaction to electrical nerve stimulation, they will be excluded.

7 days

The study intervention utilized a stimulator designed for home use. This design has additional hardware and software features that reduces the chance of and adverse event. On the hardware, the device runs off 4 double AA batteries opposed to plugged into an outlet. On software, initiation of the device is dependent on the corresponding web portal which is programmed to limit use duration per session and to one session per day.

The study enrolled only participant into the older adult group. This participant was unable to use the stimulator. To understand the feasibility of this intervention in this group many more older adult participants would need to be enrolled.