Effect of tACS Stimulation on Alpha Oscillations

Not Applicable

Completed

Conditions: Healthy

Interventions: Device: XCSITE100 Stimulator tACS
Device: XCSITE100 Stimulator Sham

Registration Number: NCT03178344

Lead Sponsor: University of North Carolina, Chapel Hill

Brief Summary: Transcranial Alternating Current Stimulation (tACS) is one method that has been demonstrated to enhance alpha oscillations in healthy participants by applying weak electrical currents to the scalp to modulate rhythmic brain activity patterns. This study will involve tACS-induced frontal alpha oscillations, EEG recordings, and other physiological and biological measures.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 20

Inclusion Criteria

Ages 18-65
Capacity to understand all relevant risks and potential benefits of the study (informed consent)
Negative pregnancy test for female participants

Exclusion Criteria

History of major neurological or psychiatric illness, including epilepsy
Medication use associated with neurological or psychiatric illnesses
Currently undergoing counseling or psychotherapy treatment for depression, anxiety, eating disorders, PTSD or other behavioral conditions
First degree relative (parent, sibling, child) with major neurological or psychiatric illness
Prior brain surgery
Major head injury
Any brain devices/implants (including cochlear implants and aneurysm clips)
Braids or other hair styling that prevents direct access to the scalp (if removal not possible)
Skin allergies or very sensitive skin
Pregnant or nursing females
Failure to pass a urinary drug test at the first session
Use of hormonal birth control or supplements in the past two weeks
Non English speakers
Cardiovascular disease

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Sham Stimulation, then Alpha Stimulation	XCSITE100 Stimulator Sham	Participants receive sham stimulation at the first session, followed by a 5-9 day washout period and alpha stimulation at the second session. Sham Stimulation mimics the physical effects of stimulation, with up to one minute of stimulation during the session. Sham stimulation is delivered using the XCSITE100 Stimulator Sham. Participants will receive 2 mA of alternating current stimulation at a frequency of 10 Hz for 40 minutes. tACS stimulation is delivered using the XCSITE100 Stimulator tACS.
Alpha Stimulation, then Sham Stimulation	XCSITE100 Stimulator Sham	Participants receive alpha stimulation at the first session, followed by a 5-9 day washout period and sham stimulation at the second session. Participants will receive 2 mA of alternating current stimulation at a frequency of 10 Hz for 40 minutes. tACS stimulation is delivered using the XCSITE100 Stimulator tACS. Sham Stimulation mimics the physical effects of stimulation, with up to one minute of stimulation during the session. Sham stimulation is delivered using the XCSITE100 Stimulator Sham.
Sham Stimulation, then Alpha Stimulation	XCSITE100 Stimulator tACS	Participants receive sham stimulation at the first session, followed by a 5-9 day washout period and alpha stimulation at the second session. Sham Stimulation mimics the physical effects of stimulation, with up to one minute of stimulation during the session. Sham stimulation is delivered using the XCSITE100 Stimulator Sham. Participants will receive 2 mA of alternating current stimulation at a frequency of 10 Hz for 40 minutes. tACS stimulation is delivered using the XCSITE100 Stimulator tACS.
Alpha Stimulation, then Sham Stimulation	XCSITE100 Stimulator tACS	Participants receive alpha stimulation at the first session, followed by a 5-9 day washout period and sham stimulation at the second session. Participants will receive 2 mA of alternating current stimulation at a frequency of 10 Hz for 40 minutes. tACS stimulation is delivered using the XCSITE100 Stimulator tACS. Sham Stimulation mimics the physical effects of stimulation, with up to one minute of stimulation during the session. Sham stimulation is delivered using the XCSITE100 Stimulator Sham.

Primary Outcome Measures

Name	Time	Method
Salivary Cortisol	Before and after 40 minutes of stimulation	Change before and after stimulation
Salivary Alpha Amylase	Before and after 40-minute stimulation at each session.	Change after stimulation

Secondary Outcome Measures

Name	Time	Method
Heart Rate Variability	Before and after 40-minute stimulation at each session.	Change in the ratio between the power in low frequency band and the power in high frequency band. As this outcome variable is a ratio between two items that are measured in microvolt\^2, the ratio does not have a unit of measure.
Percent Change in Respiration	Before and after 40-minute stimulation at each session.	Respiration rate, measured via a belt placed around the participant's abdomen as breaths per second.
Electroencephalogram (EEG)	Before and after 40-minute stimulation at each session.	The investigators will compare alpha oscillation power from resting-state EEG recordings before and after stimulation/sham at each session.