Effects of Alpha tACS

NCT03135639 | Completed

• 1 other identifier: 13-3918
• Study Type: interventional
• Target: 32
• Locations: 0 countries
• Sites: N/A

Brief Summary

\*\*Follow-up Control Study for Creativity Study Purpose: To investigate the effect of transcranial alternating current stimulation (tACS), a form of noninvasive brain stimulation, in healthy subjects. This experiment is a follow-up to previous tACS studies that used a creativity assessment. Participants: 35 males and females, at least 18 years of age, without history of major psychiatric/neurological disease or associated medication use, or prior brain surgery/implants. Procedures (methods): This is a cross-over study design. Participants will undergo a control condition of stimulation (sham or individual alpha, 8-12 Hz, tACS) during electroencephalogram recordings. In addition, pupil diameter, heart rate, and respiration will be measured continuously. This is to study the physiological effects of stimulation.

Conditions

Healthy

Keywords

tACS; transcranial alternating current stimulation; stimulation; healthy control; alpha oscillations; heart rate variability

Outcome Measures

Primary Outcomes (1)

• Electroencephalogram power in alpha band

  Changes in the EEG power in the alpha (8-12 Hz) band before and after stimulation sessions.

  5 minute recordings before and after each 20 minute stimulation session during a single study visit.

Secondary Outcomes (2)

• Heart Rate Variability

  5 minute recordings before and after each 20 minute stimulation session during a single study visit.

• Pupil diameter

  5 minute recordings before and after each 20 minute stimulation session during a single study visit.

Study Arms (2)

Sham Stim followed by Alpha Stim

EXPERIMENTAL

20 minutes of sham stimulation (sham stim) is followed by a washout period of 20 minutes. 20 minutes of alpha stimulation (alpha stim) is applied next. Sham stimulation mimics the physical effects of stimulation, with up to 1 minute of stimulation during the session. Sham stimulation is delivered using the NeuroConn Plus Stimulator Sham. Participants will receive 2 mA alternating current stimulation at their individual alpha frequency (8-12 Hz, as determined by the 2 minute resting state EEG) for 20 minutes. Alpha stimulation is delivered using the NeuroConn Plus Stimulator tACS.

Other: NeuroConn Plus Stimulator tACS; Other: NeuroConn Plus Stimulator Sham

Alpha Stim followed by Sham Stim

EXPERIMENTAL

20 minutes of alpha stimulation (alpha stim) is followed by a washout period of 20 minutes. 20 minutes of sham stimulation (sham stim) is applied next. Participants will receive 2 mA alternating current stimulation at their individual alpha frequency (8-12 Hz, as determined by the 2 minute resting state EEG) for 20 minutes. Alpha stimulation is delivered using the NeuroConn Plus Stimulator tACS. Sham stimulation mimics the physical effects of stimulation, with up to 1 minute of stimulation during the session. Sham stimulation is delivered using the NeuroConn Plus Stimulator Sham.

Other: NeuroConn Plus Stimulator tACS; Other: NeuroConn Plus Stimulator Sham

Interventions

NeuroConn Plus Stimulator tACS OTHER

Transcranial alternating current stimulation (tACS) is a novel, noninvasive brain stimulation approach in which weak electric currents are applied to the scalp. The electric currents that are applied to the scalp are in a sine-wave pattern.

Also known as: tACS

Alpha Stim followed by Sham Stim; Sham Stim followed by Alpha Stim

NeuroConn Plus Stimulator Sham OTHER

For sham stimulation, the participant receives up to 1 minute of tACS stimulation until the stimulation fades. This mimics the same skin sensations that a participant would experience during a tACS session.

Also known as: Sham tACS

Alpha Stim followed by Sham Stim; Sham Stim followed by Alpha Stim

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Males and females at least 18 years of age

You may not qualify if:

• 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 behavior conditions
• First degree relative (parent, sibling, child) with neurological or psychiatric illness (past and present)
• Prior brain surgery
• Head injury
• Any brain devices/implants (including cochlear implants and aneurysm clips)
• Cardiovascular disease
• Pregnancy

Sponsors & Collaborators

• University of North Carolina, Chapel Hill: lead

Study Officials

• Flavio Frohlich, PhD

  University of North Carolina, Chapel Hill

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: This is a double-blind study, meaning that neither the participant nor the experimenter knows what kind of stimulation the participant is receiving. An unblinded monitor (separate from the staff that interacts with the participant) is responsible for creating the stimulation codes that run each session and for ensuring that these codes worked correctly.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Each participant will receive sham stimulation or stimulation at their individual alpha frequency (8-12 Hz) during a study visit. The order is randomized (i.e., half of participants will receive sham stimulation during the first stimulation session and half will receive sham stimulation during the second stimulation session).

Study Record Dates

• First Submitted: April 20, 2017
• First Posted: May 1, 2017
• Study Start: August 1, 2016
• Primary Completion: April 1, 2017
• Study Completion: April 1, 2017
• Last Updated: August 19, 2019

Record last verified: 2017-04

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ICF, ANALYTIC CODE
• Time Frame: Data will be available starting from 1 year after publication.
• Access Criteria: Data will be available for other publications or other brain stimulation researchers. Sharing is at the discretion of the PI.