Recruiting

Observational StudyCausal Role of the Aperiodic Signal for Working Memory

Sponsor:

Florida State University

Code:

NCT06126809

Conditions

Executive Dysfunction

Eligibility Criteria

Sex: All

Age: 18 - 35

Healthy Volunteers: Accepted

Interventions

Steep-tRAS

Flat-tRAS

Sham-tRAS

Study Details

Brief summary:

Working memory (WM) is the ability to hold relevant information in mind in the absence of sensory input. The capacity for WM is a foundation for cognitive control and higher cognitive function more broadly. Previous research demonstrated that during the delay period of WM tasks, oscillatory electrical activity in the prefrontal cortex in the theta-frequency band (4-8 Hz) increased in amplitude. However, other groups found that the slope of the aperiodic signal in the brain was positively correlated with individual differences in WM capacity. Since low-frequency power and a steeper slope of the aperiodic signal are confounded in many analyses, it is not clear whether the slope of the aperiodic signal or the amplitude of low-frequency oscillations underlie WM capacity. With many studies investigating the causal role of theta oscillations in WM, the purpose of this project is to investigate the role of the aperiodic signal in WM performance.

Conditions

Executive Dysfunction

Study ID

NCT06126809

Start date

Mar 25, 2024

Status verified date

Aug, 2026

Completion date

Dec, 2027

Anticipated

Primary completion date

Dec, 2027

Anticipated

Eligibility Criteria

Sex: All

Age: 18 - 35

Healthy Volunteers: Accepted

Inclusion Criteria:

Between the ages of 18 and 35
Able to provide informed consent
Normal or corrected-to-normal vision
Willing to comply with all study procedures and be available for the duration of the study
Ability to speak, read and understand English without a translator
Not color-blind

Exclusion Criteria:

ADHD/ADD (currently under treatment)
Neurological disorder and conditions
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 traumatic brain injury
(For females) Pregnant
Anything that, in the opinion of the investigator, would place the participant at increased risk or preclude the participant's full compliance with or completion of the study
Current use of medications know to produce specific EEG activity known to disrupt interpretations of the findings including but not limited to: benzodiazepines, antipsychotics, antiepileptics and central nervous system stimulants

Study Design

Enrollment

30 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Steep-tRAS,

Transcranial random aperiodic stimulation (tRAS) delivers 1 milliampere (mA) zero-to-peak amplitude at the target electrodes and 2 mA at the return electrode. The condition of interest, steep-tRAS, mimics a steep slope of the aperiodic signal characterized by greater low relative to high frequency power. Participants receive all three types of stimulation in an intermixed, balanced, and randomized order. There are twelve total blocks of approximately five minutes of stimulation with four blocks of each type of stimulation.

active comparator: Flat-tRAS

Transcranial random aperiodic stimulation (tRAS) delivers 1 milliampere (mA) zero-to-peak amplitude at the target electrodes and 2 mA at the return electrode. The active control, flat-tRAS, mimics a flat slope aperiodic signal characterized by greater high relative to low frequency power. Participants receive all three types of stimulation in an intermixed, balanced, and randomized order. There are twelve total blocks of approximately five minutes of stimulation with four blocks of each type of stimulation.

sham comparator: Sham-tRAS

Transcranial random aperiodic stimulation (tRAS) delivers 1 milliampere (mA) zero-to-peak amplitude at the target electrodes and 2 mA at the return electrode. For active sham stimulation, steep-tRAS or flat-tRAS is delivered for only 15 seconds at the beginning and end of the block. This mimics the skin sensations (e.g., itching, burning, tingling) to assist with blinding the participant. Participants receive all three types of stimulation in an intermixed, balanced, and randomized order. There are twelve total blocks of approximately five minutes of stimulation with four blocks of each type of stimulation.

Interventions

Steep-tRAS

Stimulation will be delivered via the NeuroConn Direct Current Stimulator Plus Multiple Channels, an investigational electrical non-invasive brain stimulation device that is being used for foundational neuroscience and translational research.

Flat-tRAS

Sham-tRAS

Primary outcome measure

Change in number of remembered items [ Time Frame: 3 hours ]

Central Contacts and Locations

Central contacts

Justin Riddle, PhD

850-645-2389 jriddle@fsu.edu

Lauren Jackson, BS

850-644-9869 lauren.jackson@fsu.edu

Locations

Florida State University

Recruiting

Tallahassee, Florida, United States, 32306

Contacts

Justin Riddle, PhD

850-645-2389 jriddle@fsu.edu

Principal Investigator:

Justin Riddle, PhD

More Information

Sponsor

Florida State University

Last update posted

Aug 31, 2026

Last verified

Aug, 2026

Keywords

cognitive control
working memory
electroencephalography
transcranial electrical stimulation

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Florida State University on 2026-08-31.