Modulation of Brain Oscillations Underlying Working Memory

Mass General Brigham

Status: Enrolling

Conditions: Working Memory

Treatments: Device: Placebo tACS; Device: Active tACS

Study type: Interventional

Funder types: Other

Identifiers

NCT05923606

2023P001479

Details and patient eligibility

About

This study will use novel transcranial alternating current stimulation (tACS) protocols and electroencephalography (EEG) to modulate and measure brain oscillations that underlie working memory. tACS is a noninvasive method used to modulate the timing and patterns of brain rhythms via weak electric currents passed through electrodes on the scalp.

Full description

In this study, healthy adult individuals will perform a spatial working memory task as investigators record scalp EEG before and immediately after undergoing transcranial alternating current stimulation (tACS). Each participant will complete four tACS sessions in randomized order: 1) theta-nested gamma tACS applied during active task periods, 2) theta-nested gamma tACS applied during passive (rest) periods, 3) gamma stimulation applied in phase with ongoing theta oscillations, and 4) placebo tACS. The different stimulation protocols will take place on different days. Therefore, participants will be expected to attend 4 in-person study visits at the Martinos Center for Biomedical Imaging in Charlestown, Massachusetts.

Enrollment: 32 estimated patients

Sex: All

Ages: 18 to 35 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Able to provide informed consent
• Fluent in English.

Exclusion criteria

• History of a neurological/psychiatric disorder
• Current use of psychotropic medications
• Current use of substances and drugs that were shown to affect tES (transcranial electrical stimulation) efficacy (dopamine altering drugs, nicotine, NMDA (N-methyl-D-aspartate) antagonists/agonists, sodium/calcium channel blockers, norepinephrine reuptake inhibitors, GABAergic modulators and selective serotonin reuptake inhibitors)
• Contraindications for tACS (e.g., history of seizures, metallic implants in the head or neck, implanted brain stimulators, vagus nerve stimulators, pacemakers, pregnancy)

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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32 participants in 4 patient groups, including a placebo group

Theta-nested gamma tACS applied during passive task epochs

Experimental group

Description:

Participants will receive single-session administration of tACS during performance of a working memory task. tACS will be applied during fixation periods between consecutive task trials. EEG will be acquired before and immediately after the intervention.

Treatment:

Device: Active tACS

Theta-nested gamma tACS applied during memory delays

Experimental group

Description:

Participants will receive single-session administration of tACS during performance of a working memory task. tACS will be applied during memory delays. EEG will be acquired before and immediately after the intervention.

Treatment:

Device: Active tACS

Gamma tACS applied during memory delays

Experimental group

Description:

Participants will receive single-session administration of tACS during performance of a working memory task. tACS will be applied during memory delays. The stimulation will be phase locked to the peaks of ongoing theta rhythms of the participant. EEG will be acquired before and immediately after the intervention.

Treatment:

Device: Active tACS

Placebo tACS applied during task performance

Placebo Comparator group

Description:

Participants will receive single-session administration of placebo tACS during performance of a working memory task. EEG will be acquired before and immediately after the intervention.

Treatment:

Device: Placebo tACS