Executive DysfunctionTRASNCT06126809
Causal Role of the Aperiodic Signal for Working Memory
A study testing Steep-tRAS and Flat-tRAS in people with Executive Dysfunction, run by Florida State University at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Executive Dysfunction
- What is being tested?
- Steep-tRAS and Flat-tRAS
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 30 participants
- Where
- 1 siteUnited States
- Study dates
- 25 Mar 2024to Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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
Who cannot join
- 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
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- (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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Florida State University
Tallahassee, Florida, 32306
Justin Riddle, PhD, 850-645-2389, jriddle@fsu.edu
Justin Riddle, PhD
About this study
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.
Read the detailed description
The experiment comprises two experimental sessions. The first session serves as a baseline session where electroencephalography (EEG) is recorded during working memory (WM) task performance. The difficulty of the task is titrated to the individual participant and they are familiarized with the task. In the second session, the participant receives each type of transcranial random aperiodic stimulation (tRAS): steep-tRAS, flat-tRAS, sham-tRAS. Stimulation is delivered in one of these three waveforms for each block while the participant performs the WM task. The type of stimulation that is received is balanced, randomized, and intermixed by block. This study is double-blinded such that the participant and the researcher are not aware of what type of stimulation is being delivered. Each block is approximately 5 minutes and twelve total blocks are collected with stimulation. The type of tRAS for that block (steep-tRAS, flat-tRAS, or sham-tRAS) is started just prior to the beginning of the task block and ramps down at the end of the task block. For each task block, the tRAS takes 15 seconds to ramp up at the beginning and 15 seconds to ramp down at the conclusion of the task block. In total, the participant receives approximately 60 minutes of stimulation, which is approximately 20 minutes of each type of stimulation. Following each task block, participants stare at a fixation cross and relax without stimulation. This "resting-state" EEG recording is used to assess the aftereffects of tRAS on brain activity. The first session will take 2 hours to complete and the second session will take 3 hours to complete.
- Conditions
- Executive Dysfunction
- Being tested
- Steep-tRAS, Flat-tRAS, Sham-tRAS
- Keywords
- cognitive control, working memory, electroencephalography, transcranial electrical stimulation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Steep-tRASDevice
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-tRASDevice
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.
Sham-tRASDevice
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.
| Study group | Role | What they receive |
|---|---|---|
| Steep-tRAS, | Experimental | 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. Receives: Device: Steep-tRAS |
| Flat-tRAS | Active comparator | 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. Receives: Device: Flat-tRAS |
| Sham-tRAS | Sham comparator | 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. Receives: Device: Sham-tRAS |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in 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 multiplied by the number of items successfully remembered divided by the number of total trials. The range of values is 0 to 7 where a larger number denotes a greater number of items that were remembered.
Measured: 3 hours
Secondary outcomes (1)
Change in slope of the power spectrum of the EEG
The power spectrum of an electrical brain recording is calculated by performing a Fourier transform on the time signal. The slope is calculated as the general trend of this background signal.
Measured: 3 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Nov 2023
- Study start25 Mar 2024
- Primary completionDec 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Executive DysfunctionStudies of the same condition, open and under way.
- More trials run by Florida State UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- All participants receive all three types of transcranial random aperiodic stimulation (tRAS): steep-tRAS, flat-tRAS, and sham-tRAS. The type of stimulation received is randomized and intermixed for each task block lasting approximately 5 minutes. The participant receives 12 task blocks, each with one of the stimulation types that are randomized, intermixed, and balanced for order.
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Florida State University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Justin Riddle, Florida State University
- Investigators
- Justin Riddle, PhD, Principal investigator, Florida State University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06126809
- Sponsor's protocol ID
- STUDY00004479
- Acronym
- TRAS
- Status last verified
- Aug 2026
- First submitted
- 7 Nov 2023
- Last updated
- 31 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: 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 FSU.
Study at a glance
From the registry record, last updated by the sponsor on 31 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Causal Role of the Aperiodic Signal for Working Memory
- ClinicalTrials.gov ID
- NCT06126809
- Acronym / sponsor ID
- TRAS / STUDY00004479
- Conditions
- Executive Dysfunction
- Keywords
- cognitive control, working memory, electroencephalography, transcranial electrical stimulation
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Florida State UniversityUniversity, hospital or other
- Study start
- 25 Mar 2024 (actual)
- Primary completion
- Dec 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 13 Nov 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
The experiment comprises two experimental sessions. The first session serves as a baseline session where electroencephalography (EEG) is recorded during working memory (WM) task performance. The difficulty of the task is titrated to the individual participant and they are familiarized with the task. In the second session, the participant receives each type of transcranial random aperiodic stimulation (tRAS): steep-tRAS, flat-tRAS, sham-tRAS. Stimulation is delivered in one of these three waveforms for each block while the participant performs the WM task. The type of stimulation that is received is balanced, randomized, and intermixed by block. This study is double-blinded such that the participant and the researcher are not aware of what type of stimulation is being delivered. Each block is approximately 5 minutes and twelve total blocks are collected with stimulation. The type of tRAS for that block (steep-tRAS, flat-tRAS, or sham-tRAS) is started just prior to the beginning of the task block and ramps down at the end of the task block. For each task block, the tRAS takes 15 seconds to ramp up at the beginning and 15 seconds to ramp down at the conclusion of the task block. In total, the participant receives approximately 60 minutes of stimulation, which is approximately 20 minutes of each type of stimulation. Following each task block, participants stare at a fixation cross and relax without stimulation. This "resting-state" EEG recording is used to assess the aftereffects of tRAS on brain activity. The first session will take 2 hours to complete and the second session will take 3 hours to complete.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 3
- Model description
- All participants receive all three types of transcranial random aperiodic stimulation (tRAS): steep-tRAS, flat-tRAS, and sham-tRAS. The type of stimulation received is randomized and intermixed for each task block lasting approximately 5 minutes. The participant receives 12 task blocks, each with one of the stimulation types that are randomized, intermixed, and balanced for order.
| Arm | Type | Receives |
|---|---|---|
| Steep-tRAS, | Experimental | Device: Steep-tRASTranscranial 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. |
| Flat-tRAS | Active comparator | Device: Flat-tRASTranscranial 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-tRAS | Sham comparator | Device: Sham-tRASTranscranial 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. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- 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
Key exclusion criteria (9 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Steep-tRASStimulation 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. | Device | Steep-tRAS, |
| Flat-tRASStimulation 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. | Device | Flat-tRAS |
| Sham-tRASStimulation 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. | Device | Sham-tRAS |
Primary outcome
Change in number of remembered items
Time frame: 3 hours
The number of remembered items, often referred to as working memory capacity, is calculated as the number of items to be remembered multiplied by the number of items successfully remembered divided by the number of total trials. The range of values is 0 to 7 where a larger number denotes a greater number of items that were remembered.
1 secondary outcome
Change in slope of the power spectrum of the EEG
Time frame: 3 hours
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 Aug 2026.
- Individual participant dataSharing planned: Yes. 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 FSU.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Justin Riddle, PhD principal investigator
Florida State University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Steep-tRAS and Flat-tRAS in people with Executive Dysfunction, run by Florida State University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 31 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Justin Riddle, PhD (850-645-2389, jriddle@fsu.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in number of remembered items (time frame: 3 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 Aug 2026.