Theta Connectivity in Working Memory
STAR
Causal Role of Theta and Alpha Oscillations in Output-gating
2 other identifiers
interventional
71
1 country
1
Brief Summary
The participants will perform a cognitive control task. During the task, rhythmic trains of transcranial magnetic stimulation will be delivered to the prefrontal cortex and parietal cortex. Participants will be screened for their ability to perform the task. Magnetic resonance imaging will be used to localize regions of interest to be targeted. Electroencephalography will be collected concurrent with stimulation.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for not_applicable
Started Jan 2022
Typical duration for not_applicable
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
January 11, 2022
CompletedFirst Posted
Study publicly available on registry
January 24, 2022
CompletedStudy Start
First participant enrolled
January 24, 2022
CompletedPrimary Completion
Last participant's last visit for primary outcome
December 20, 2024
CompletedStudy Completion
Last participant's last visit for all outcomes
December 20, 2024
CompletedResults Posted
Study results publicly available
November 20, 2025
CompletedNovember 20, 2025
January 1, 2025
2.9 years
January 11, 2022
October 14, 2025
November 6, 2025
Conditions
Outcome Measures
Primary Outcomes (2)
Number of Remembered Items
The number of remembered items, often referred to as working memory capacity, is calculated as the number of items to be remembered (2, 3, or 4) times the hit rate minus the false alarm rate, divided by one minus the false alarm rate. The range of values is 0 to 4 where larger values mean better performance.
Measured concurrent with stimulation throughout a 3-hour session
Strength of Functional Connectivity Between Frontal and Parietal Cortex in Theta-frequency
Functional connectivity will be measured using weighted phase lag index (wPLI) which is the mean of the imaginary component of the difference in theta-frequency phase between frontal and parietal electrical activity during the second half of the stimulation train for every trial. The values range from 0 to 1 where a greater value represents greater functional connectivity.
Measured concurrent with stimulation throughout a 3-hour session
Secondary Outcomes (1)
Average Phase Lag of Functional Connectivity Between Frontal and Parietal Cortex in Theta-frequency
Measured concurrent with stimulation throughout a 3-hour session
Study Arms (2)
Theta Stimulation
EXPERIMENTALRhythmic transcranial magnetic stimulation (TMS) is delivered to frontal and parietal cortex during performance of a cognitive control task while electroencephalography (EEG) is recorded. In the fourth and fifth sessions, stimulation is delivered in near-zero phase lag theta-frequency, anti-synchrony theta-frequency, near-zero phase lag arrhythmic-in-synchrony stimulation, and arrhythmic-independent stimulation. The near-zero phase lag arrhythmic-in-synchrony stimulation and arrhythmic-independent stimulation is delivered in both the fourth and fifth session to serve as an active control. Each session is separated by at least one day as a washout period.
Alpha Stimulation
EXPERIMENTALRhythmic transcranial magnetic stimulation (TMS) is delivered to frontal and parietal cortex during performance of a cognitive control task while electroencephalography (EEG) is recorded. In the fourth and fifth sessions, stimulation is delivered in near-zero phase lag alpha-frequency, anti-synchrony alpha-frequency, near-zero phase lag arrhythmic-in-synchrony stimulation, and arrhythmic-independent stimulation. The near-zero phase lag arrhythmic-in-synchrony stimulation and arrhythmic-independent stimulation is delivered in both the fourth and fifth session to serve as an active control. Each session is separated by at least one day as a washout period.
Interventions
Rhythmic transcranial magnetic stimulation (TMS) is delivered to both frontal and parietal cortex in theta-frequency (approximately 6 Hz) with a near-zero phase lag.
Rhythmic transcranial magnetic stimulation (TMS) is delivered to both frontal and parietal cortex in theta-frequency (approximately 6 Hz) with a 180 degree phase offset, anti-synchrony.
Rhythmic transcranial magnetic stimulation (TMS) is delivered to both frontal and parietal cortex in an arrhythmic pattern with a near-zero phase lag matched in duration to the rhythmic stimulation for that session.
Rhythmic transcranial magnetic stimulation (TMS) is delivered to both frontal and parietal cortex in different independent arrhythmic patterns matched in duration to the rhythmic stimulation for that session.
Rhythmic transcranial magnetic stimulation (TMS) is delivered to both frontal and parietal cortex in alpha-frequency (approximately 10 Hz) with a near-zero phase lag.
Rhythmic transcranial magnetic stimulation (TMS) is delivered to both frontal and parietal cortex in alpha-frequency (approximately 10 Hz) with a 180 degree phase offset, anti-synchrony.
Eligibility Criteria
You may qualify if:
- Between the ages of 18 and 35
- Right-handed
- Able to provide informed consent
- Have normal to corrected vision without color blindness
- Willing to comply with all study procedures and be available for the duration of the study Speak and understand English
- Participants will be invited back to the second session only if they are able to perform the task. The criteria for demonstrating the cognitive process of interest is that participants must show a benefit to their working memory percent correct during trials with an informative retro-cue relative to trials with an uninformative neutral cue
You may not qualify if:
- Attention Deficit Hyperactivity Disorder (ADHD) (currently under treatment)
- Neurological disorders and conditions, including, but not limited to:
- History of epilepsy
- Seizures (except childhood febrile seizures) Dementia
- History of stroke
- Parkinson's disease
- Multiple sclerosis
- Cerebral aneurysm
- Brain tumors
- Medical or neurological illness or treatment for a medical disorder that could interfere with study participation (e.g., unstable cardiac disease, HIV/AIDS, malignancy, liver or renal impairment)
- Prior brain surgery
- Any brain devices/implants, including cochlear implants and aneurysm clips
- History of current traumatic brain injury
- Failure to pass a colorblindness test
- (For females) Pregnancy or breast feeding
- +1 more criteria
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
University of North Carolina at Chapel Hill
Chapel Hill, North Carolina, 27599, United States
Results Point of Contact
- Title
- Zachary Stewart
- Organization
- University of North Carollina at Chapel Hill
Study Officials
- PRINCIPAL INVESTIGATOR
Flavio Frohlich, PhD
University of North Carolina, Chapel Hill
Publication Agreements
- PI is Sponsor Employee
- Yes
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- SINGLE
- Who Masked
- PARTICIPANT
- Purpose
- BASIC SCIENCE
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
January 11, 2022
First Posted
January 24, 2022
Study Start
January 24, 2022
Primary Completion
December 20, 2024
Study Completion
December 20, 2024
Last Updated
November 20, 2025
Results First Posted
November 20, 2025
Record last verified: 2025-01
Data Sharing
- IPD Sharing
- Will share
- Shared Documents
- STUDY PROTOCOL, SAP, ICF
- Time Frame
- From 9 to 36 months following publication
- Access Criteria
- Investigator who proposes to use the data has IRB, IEC, or REB approval and an executed data use/sharing agreement with the University of North Carolina at Chapel Hill.
Deidentified individual data that supports the results will be shared beginning 9 to 36 months following publication provided the investigator who proposes to use the data has approval from an Institutional Review Board (IRB), Independent Ethics Committee (IEC), or Research Ethics Board (REB), as applicable, and executes a data use/sharing agreement with the University of North Carolina at Chapel Hill.