HealthyNCT06344559
Brain Criticality, Oculomotor Control, and Cognitive Effort
A study testing transcranial magnetic stimulation in people with Healthy, run by Rutgers, The State University of New Jersey at 1 site in United States.
Trial summary
The project examines electroencephalography, MRI, and behavioral measures indexing flexibility (critical state dynamics) in the brain when healthy young adults do demanding cognitive tasks, and in response to transcranial magnetic stimulation. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- transcranial magnetic stimulation
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Aug 2024to 1 Jun 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Provision of signed and dated informed consent form
- Stated willingness to comply with all study and availability for the duration of the study
- Males and females; Ages 18-45
- Healthy, neurologically normal with no diagnosed mental or physical illness
- Willingness to adhere to the MRI and two session stimulation protocol
- Fluent in English
- Normal or corrected to normal vision
- At least twelve years of education (high school equivalent)
Who cannot join
- Ongoing drug or alcohol abuse
- Diagnosed psychiatric or mental illness
- Currently taking psychoactive medication
- Prior brain injury
- Metal in body
- History of seizures or diagnosis of epilepsy
Show all 10Show fewer
- Claustrophobia
- Pregnant or possibly pregnant
- Younger than 18 or older than 45
- Use of medications which potentially lower the usage threshold
Trial locations and contacts
1 site in 1 country.
United States1 site, 1 recruiting
- Recruiting
Center for Advanced Human Brain Imaging Research
Piscataway, New Jersey, 08854
Andrew Westbrook, PhD, 919-360-5399, andrew.westbrook@rutgers.edu
About this study
Official title: Theta-burst Stimulation Modulates Criticality and Cognitive Control
The project examines electroencephalography, MRI, and behavioral measures indexing flexibility (critical state dynamics) in the brain when healthy young adults do demanding cognitive tasks, and in response to transcranial magnetic stimulation.
Read the detailed description
The healthy human brain is a complex, dynamical system which is hypothesized to operate, at rest, near a phase transition - at the boundary between order and chaos. Proximity to this critical point is functionally adaptive as it affords maximal flexibility, dynamic range, and information transmission capacity, with implications for short term memory and cognitive control. Divergence from this critical point has become correlated with diverse forms of psychopathology and neuropathy suggesting that distance from a critical point is both a potential biomarker of disorder and also a target for intervention in disordered brains. The Investigators have further hypothesized that task performance depends on how closely brains operate to criticality during task performance and also that subjective cognitive effort is a reflection of divergence from criticality, induced by engagement with demanding tasks.
A key control parameter determining distance from criticality in a resting brain is hypothesized to be the balance of cortical excitation to inhibition (the "E/I balance"). Transcranial magnetic stimulation is a widely used experimental and clinical tool for neuromodulation and theta-burst stimulation (TBS) protocols are thought to modulate the E/I balance. Here the Investigators test whether cortical dynamics can be systematically modulated away from the critical point with continuous theta-burst stimulation (cTBS) and intermittent theta-burst stimulation (iTBS), which is thought to decrease and increase E/I balance, respectively. Depending on baseline E/I balance prior to stimulation, this will make people's brains either operate closer to, or farther away from critiality and thereby impact on cognitive control and subjective cognitive effort during performance of control-demanding tasks.
- Conditions
- Healthy
- Being tested
- transcranial magnetic stimulation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
transcranial magnetic stimulationDevice
The study intervention involves modulation of cortical excitation to inhibition (E/I) balance in the right frontal eye field (FEF) by means of 2 trains of spaced continuous or intermittent theta burst stimulation (cTBS, iTBS, respectively) using a transcranial magnetic stimulation device. The endpoint of this stimulation will be a decrease (cTBS) or increase (iTBS) in the local E/I ratio that should last at least 60 minutes post-stimulation (Chung et al., 2016).
In separate sessions, all participants will receive either active or stimulation to the FEF. The Investigators will contrast the effects of both iTBS and cTBS to sham stimulation and to each other.
| Study group | Role | What they receive |
|---|---|---|
| Continuous theta burst stimulation | Active comparator | In a cross-over design, all participants will, in one session, receive continuous theta burst stimulation, to the right frontal eye field. Session order will be counter-balanced across participants, and stimulation protocol will be blinded to participants and the Investigator until after data collection is complete. Receives: Device: transcranial magnetic stimulation |
| Intermittent theta burst stimulation | Active comparator | In a cross-over design, all participants will, in one session, receive intermittent theta burst stimulation, to the right frontal eye field. Session order will be counter-balanced across participants, and stimulation protocol will be blinded to participants and the Investigator until after data collection is complete. Receives: Device: transcranial magnetic stimulation |
| Sham theta burst stimulation | Sham comparator | In a cross-over design, all participants will, in one session, receive sham theta burst stimulation, to the right frontal eye field. Session order will be counter-balanced across participants, and stimulation protocol will be blinded to participants and the Investigator until after data collection is complete. Receives: Device: transcranial magnetic stimulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Critical dynamics - immediate effects of cTBS versus sham stimulation
Long-range temporal correlations quantified by the scaling exponent, which is derived from EEG data, via detrended fluctuation analysis. Scores range from 0.5 (uncorrelated time series) to 1.0 (correlated time series). Lower scores, indicating weaker correlations, are expected following active continuous theta burst stimulation (cTBS) versus sham stimulation. So, the difference score should be negative, indicating weaker long-range temporal correlations as a result of cTBS, immediately after stimulation.
Measured: Change in correlations recorded during rest, immediately after stimulation, for active versus sham stimulation.
Functional E/I balance - immediate effects of cTBS versus sham stimulation
The functional E/I ratio, which is derived from a comparison of band-limited amplitude to the fluctuation function, reflects the balance of excitation versus inhibition driving the associated oscillations. Scores range from approximately 0.5 to 1.5 with values below 1.0 indicating inhibition dominance and values above 1.0 indicating excitation dominance. Lower scores, indicating more inhibition dominance, are expected following active continuous theta burst stimulation (cTBS) versus sham stimulation. So, the difference score should be negative, indicating a lower E/I balance as a result of cTBS, immediately after stimulation.
Measured: Change in the functional E/I balance recorded during rest, immediately after stimulation, for active versus sham stimulation.
Avalanche branching ratio - immediate effects of cTBS versus sham stimulation
The growth rate of neuronal avalanches can be estimated from the clustering of high amplitude events in in electroencephalography (EEG) signal. Faster growing avalanches correspond with tighter clustering of events in time. Scores range from approximately 0.5 to 1.5 with values below 1.0 indicating inhibition dominance and values above 1.0 indicating excitation dominance. Lower scores, indicating more inhibition dominance, are expected following active continuous theta burst stimulation (cTBS) versus sham stimulation. So, the difference score should be negative, indicating a lower E/I balance as a result of cTBS, immediately after stimulation.
Measured: Change in the avalanche branching ratio recorded during rest, immediately after stimulation, for active versus sham stimulation.
Critical dynamics - immediate effects of iTBS versus sham stimulation
Long-range temporal correlations quantified by the scaling exponent, which is derived from EEG data, via detrended fluctuation analysis. Scores range from 0.5 (uncorrelated time series) to 1.0 (correlated time series). Higher scores, indicating stronger correlations, are expected following active intermittent theta burst stimulation (iTBS) versus sham stimulation. So, the difference score should be positive, indicating stronger long-range temporal correlations as a result of iTBS, immediately after stimulation.
Measured: Change in correlations recorded during rest, immediately after stimulation, for active versus sham stimulation.
Functional E/I balance - immediate effects of iTBS versus sham stimulation
The functional E/I ratio, which is derived from a comparison of band-limited amplitude to the fluctuation function, reflects the balance of excitation versus inhibition driving the associated oscillations. Scores range from approximately 0.5 to 1.5 with values below 1.0 indicating inhibition dominance and values above 1.0 indicating excitation dominance. Higher scores, indicating more excitation dominance, are expected following active intermittent theta burst stimulation (iTBS) versus sham stimulation. So, the difference score should be positive, indicating a higher E/I balance as a result of iTBS, immediately after stimulation.
Measured: Change in the functional E/I balance recorded during rest, immediately after stimulation, for active versus sham stimulation.
Avalanche branching ratio - immediate effects of iTBS versus sham stimulation
The growth rate of neuronal avalanches can be estimated from the clustering of high amplitude events in in electroencephalography (EEG) signal. Faster growing avalanches correspond with tighter clustering of events in time. Scores range from approximately 0.5 to 1.5 with values below 1.0 indicating inhibition dominance and values above 1.0 indicating excitation dominance. Higher scores, indicating more excitation dominance, are expected following active intermittent theta burst stimulation (iTBS) versus sham stimulation. So, the difference score should be positive, indicating a higher E/I balance as a result of iTBS, immediately after stimulation.
Measured: Change in the avalanche branching ratio recorded during rest, immediately after stimulation, for active versus sham stimulation.
Memory-guided saccade accuracy - effects of cTBS versus sham stimulation
Accuracy on the memory-guided saccade task, as quantified by mean degrees of visual angle deviation typically range from ~1.0 to 5.0 degrees, with higher scores indicating higher inaccuracy. Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. Because criticality implies susceptibility and flexibility, stimulation protocols which make the FEF operate closer to criticality, relative to sham stimulation, will show bigger errors in degrees of visual angle.
Measured: Change in degrees of visual angle error estimated 44 minutes after stimulation, for cTBS versus sham stimulation.
Memory-guided saccade accuracy - effects of iTBS versus sham stimulation
Accuracy on the memory-guided saccade task, as quantified by mean degrees of visual angle deviation typically range from ~1.0 to 5.0 degrees, with higher scores indicating higher inaccuracy. Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. Because criticality implies susceptibility and flexibility, stimulation protocols which make the FEF operate closer to criticality, relative to sham stimulation, will show bigger errors in degrees of visual angle.
Measured: Change in degrees of visual angle error estimated 44 minutes after stimulation, for iTBS versus sham stimulation.
Anti-saccade accuracy - effects of cTBS versus sham stimulation
Accuracy on the anti-saccade task, as quantified by mean percent of correct saccades away from a cue typically ranges between 80% and 100% correct. Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. Because criticality implies greater inter-regional communication between top-down control regions and sensorimotor cortex, stimulation protocols which make the FEF operate closer to criticality, relative to sham stimulation, will a higher perfect increase in accuracy as a result of stimulation.
Measured: Change in percent accuracy estimated 12 minutes after stimulation, for cTBS versus sham stimulation.
Anti-saccade accuracy - effects of iTBS versus sham stimulation
Accuracy on the anti-saccade task, as quantified by mean percent of correct saccades away from a cue typically ranges between 80% and 100% correct. Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. Because criticality implies greater inter-regional communication between top-down control regions and sensorimotor cortex, stimulation protocols which make the FEF operate closer to criticality, relative to sham stimulation, will a higher perfect increase in accuracy as a result of stimulation.
Measured: Change in percent accuracy estimated 12 minutes after stimulation, for iTBS versus sham stimulation.
Subjective effort discounting - cTBS versus sham stimulation
Subjective values as estimated from an effort discounting procedure as a discounted offer ranging from 0.0 (full effort discounting) to 1.0 (no effort discounting). Lower values indicate that people find subjective effort to be more costly. Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. We hypothesize that divergence from criticality underlies phenomenological effort. So, we predict that stimulation which makes people's brains operate closer to criticality relative to sham will experience less effort and have a higher subjective value.
Measured: Change in subjective value estimated 72 minutes after stimulation, for cTBS versus sham stimulation.
Subjective effort discounting - iTBS versus sham stimulation
Subjective values as estimated from an effort discounting procedure as a discounted offer ranging from 0.0 (full effort discounting) to 1.0 (no effort discounting). Lower values indicate that people find subjective effort to be more costly. Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. We hypothesize that divergence from criticality underlies phenomenological effort. So, we predict that stimulation which makes people's brains operate closer to criticality relative to sham will experience less effort and have a higher subjective value.
Measured: Change in subjective value estimated 72 minutes after stimulation, for iTBS versus sham stimulation.
Subjective effort rating - cTBS versus sham stimulation
Likert ratings of subjective effort randing from 1 (low effort) to 10 (high effort). Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. We hypothesize that divergence from criticality underlies phenomenological effort. So, we predict that stimulation which makes people's brains operate closer to criticality relative to sham will experience less effort and have a higher subjective value.
Measured: Change in subjective value estimated 70 minutes after stimulation, for cTBS versus sham stimulation.
Subjective effort rating - iTBS versus sham stimulation
Likert ratings of subjective effort randing from 1 (low effort) to 10 (high effort). Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. We hypothesize that divergence from criticality underlies phenomenological effort. So, we predict that stimulation which makes people's brains operate closer to criticality relative to sham will experience less effort and have a higher subjective value.
Measured: Change in subjective value estimated 70 minutes after stimulation, for iTBS versus sham stimulation.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Apr 2024
- Study start1 Aug 2024
- Primary completion1 Jun 2026 (estimated)
- Study completion1 Jun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by Rutgers, The State University of New JerseyThe 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
- The study will involve three sessions of within-subject, crossover, double-blind transcranial magnetic stimulation with either 1) active intermittent theta burst stimulation, 2) active continuous theta burst stimulation or 3) sham intermittent or continuous theta burst stimulation.
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Rutgers, The State University of New Jersey
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Andrew Westbrook, PhD, Rutgers, The State University of New Jersey
- Investigators
- John A Westbrook, PhD, Principal investigator, Rutgers University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06344559
- Sponsor's protocol ID
- 2023001006
- Status last verified
- Aug 2024
- First submitted
- 27 Mar 2024
- Last updated
- 7 Aug 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No: All anonymized data will be made publicly available at the conclusion of the trial at Rutgers University's (RUresearch) Data Portal.
Publications
Huang YZ, Edwards MJ, Rounis E, Bhatia KP, Rothwell JC. Theta burst stimulation of the human motor cortex. Neuron. 2005 Jan 20;45(2):201-6. doi: 10.1016/j.neuron.2004.12.033.
PubMed 15664172Chung SW, Hill AT, Rogasch NC, Hoy KE, Fitzgerald PB. Use of theta-burst stimulation in changing excitability of motor cortex: A systematic review and meta-analysis. Neurosci Biobehav Rev. 2016 Apr;63:43-64. doi: 10.1016/j.neubiorev.2016.01.008. Epub 2016 Feb 3.
PubMed 26850210
Study at a glance
From the registry record, last updated by the sponsor on 7 Aug 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Theta-burst Stimulation Modulates Criticality and Cognitive Control
- ClinicalTrials.gov ID
- NCT06344559
- Acronym / sponsor ID
- 2023001006
- Conditions
- Healthy
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Rutgers, The State University of New JerseyUniversity, hospital or other
- Study start
- 1 Aug 2024 (actual)
- Primary completion
- 1 Jun 2026 (estimated)
- Study completion
- 1 Jun 2026 (estimated)
- First posted
- 3 Apr 2024 (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.
The project examines electroencephalography, MRI, and behavioral measures indexing flexibility (critical state dynamics) in the brain when healthy young adults do demanding cognitive tasks, and in response to transcranial magnetic stimulation.
Detailed description
The healthy human brain is a complex, dynamical system which is hypothesized to operate, at rest, near a phase transition - at the boundary between order and chaos. Proximity to this critical point is functionally adaptive as it affords maximal flexibility, dynamic range, and information transmission capacity, with implications for short term memory and cognitive control. Divergence from this critical point has become correlated with diverse forms of psychopathology and neuropathy suggesting that distance from a critical point is both a potential biomarker of disorder and also a target for intervention in disordered brains. The Investigators have further hypothesized that task performance depends on how closely brains operate to criticality during task performance and also that subjective cognitive effort is a reflection of divergence from criticality, induced by engagement with demanding tasks.
A key control parameter determining distance from criticality in a resting brain is hypothesized to be the balance of cortical excitation to inhibition (the "E/I balance"). Transcranial magnetic stimulation is a widely used experimental and clinical tool for neuromodulation and theta-burst stimulation (TBS) protocols are thought to modulate the E/I balance. Here the Investigators test whether cortical dynamics can be systematically modulated away from the critical point with continuous theta-burst stimulation (cTBS) and intermittent theta-burst stimulation (iTBS), which is thought to decrease and increase E/I balance, respectively. Depending on baseline E/I balance prior to stimulation, this will make people's brains either operate closer to, or farther away from critiality and thereby impact on cognitive control and subjective cognitive effort during performance of control-demanding tasks.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 3
- Model description
- The study will involve three sessions of within-subject, crossover, double-blind transcranial magnetic stimulation with either 1) active intermittent theta burst stimulation, 2) active continuous theta burst stimulation or 3) sham intermittent or continuous theta burst stimulation.
| Arm | Type | Receives |
|---|---|---|
| Continuous theta burst stimulation | Active comparator | Device: transcranial magnetic stimulationIn a cross-over design, all participants will, in one session, receive continuous theta burst stimulation, to the right frontal eye field. Session order will be counter-balanced across participants, and stimulation protocol will be blinded to participants and the Investigator until after data collection is complete. |
| Intermittent theta burst stimulation | Active comparator | Device: transcranial magnetic stimulationIn a cross-over design, all participants will, in one session, receive intermittent theta burst stimulation, to the right frontal eye field. Session order will be counter-balanced across participants, and stimulation protocol will be blinded to participants and the Investigator until after data collection is complete. |
| Sham theta burst stimulation | Sham comparator | Device: transcranial magnetic stimulationIn a cross-over design, all participants will, in one session, receive sham theta burst stimulation, to the right frontal eye field. Session order will be counter-balanced across participants, and stimulation protocol will be blinded to participants and the Investigator until after data collection is complete. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- Provision of signed and dated informed consent form
- Stated willingness to comply with all study and availability for the duration of the study
- Males and females; Ages 18-45
- Healthy, neurologically normal with no diagnosed mental or physical illness
- Willingness to adhere to the MRI and two session stimulation protocol
Key exclusion criteria (10 listed)
- Ongoing drug or alcohol abuse
- Diagnosed psychiatric or mental illness
- Currently taking psychoactive medication
- Prior brain injury
- Metal in body
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 |
|---|---|---|
| transcranial magnetic stimulationThe study intervention involves modulation of cortical excitation to inhibition (E/I) balance in the right frontal eye field (FEF) by means of 2 trains of spaced continuous or intermittent theta burst stimulation (cTBS, iTBS, respectively) using a transcranial magnetic stimulation device. The endpoint of this stimulation will be a decrease (cTBS) or increase (iTBS) in the local E/I ratio that should last at least 60 minutes post-stimulation (Chung et al., 2016). In separate sessions, all participants will receive either active or stimulation to the FEF. The Investigators will contrast the effects of both iTBS and cTBS to sham stimulation and to each other. | Device | Continuous theta burst stimulation, Intermittent theta burst stimulation, Sham theta burst stimulation |
Primary outcome
Critical dynamics - immediate effects of cTBS versus sham stimulation
Time frame: Change in correlations recorded during rest, immediately after stimulation, for active versus sham stimulation.
Long-range temporal correlations quantified by the scaling exponent, which is derived from EEG data, via detrended fluctuation analysis. Scores range from 0.5 (uncorrelated time series) to 1.0 (correlated time series). Lower scores, indicating weaker correlations, are expected following active continuous theta burst stimulation (cTBS) versus sham stimulation. So, the difference score should be negative, indicating weaker long-range temporal correlations as a result of cTBS, immediately after stimulation.
Functional E/I balance - immediate effects of cTBS versus sham stimulation
Time frame: Change in the functional E/I balance recorded during rest, immediately after stimulation, for active versus sham stimulation.
The functional E/I ratio, which is derived from a comparison of band-limited amplitude to the fluctuation function, reflects the balance of excitation versus inhibition driving the associated oscillations. Scores range from approximately 0.5 to 1.5 with values below 1.0 indicating inhibition dominance and values above 1.0 indicating excitation dominance. Lower scores, indicating more inhibition dominance, are expected following active continuous theta burst stimulation (cTBS) versus sham stimulation. So, the difference score should be negative, indicating a lower E/I balance as a result of cTBS, immediately after stimulation.
Avalanche branching ratio - immediate effects of cTBS versus sham stimulation
Time frame: Change in the avalanche branching ratio recorded during rest, immediately after stimulation, for active versus sham stimulation.
The growth rate of neuronal avalanches can be estimated from the clustering of high amplitude events in in electroencephalography (EEG) signal. Faster growing avalanches correspond with tighter clustering of events in time. Scores range from approximately 0.5 to 1.5 with values below 1.0 indicating inhibition dominance and values above 1.0 indicating excitation dominance. Lower scores, indicating more inhibition dominance, are expected following active continuous theta burst stimulation (cTBS) versus sham stimulation. So, the difference score should be negative, indicating a lower E/I balance as a result of cTBS, immediately after stimulation.
Critical dynamics - immediate effects of iTBS versus sham stimulation
Time frame: Change in correlations recorded during rest, immediately after stimulation, for active versus sham stimulation.
Long-range temporal correlations quantified by the scaling exponent, which is derived from EEG data, via detrended fluctuation analysis. Scores range from 0.5 (uncorrelated time series) to 1.0 (correlated time series). Higher scores, indicating stronger correlations, are expected following active intermittent theta burst stimulation (iTBS) versus sham stimulation. So, the difference score should be positive, indicating stronger long-range temporal correlations as a result of iTBS, immediately after stimulation.
Functional E/I balance - immediate effects of iTBS versus sham stimulation
Time frame: Change in the functional E/I balance recorded during rest, immediately after stimulation, for active versus sham stimulation.
The functional E/I ratio, which is derived from a comparison of band-limited amplitude to the fluctuation function, reflects the balance of excitation versus inhibition driving the associated oscillations. Scores range from approximately 0.5 to 1.5 with values below 1.0 indicating inhibition dominance and values above 1.0 indicating excitation dominance. Higher scores, indicating more excitation dominance, are expected following active intermittent theta burst stimulation (iTBS) versus sham stimulation. So, the difference score should be positive, indicating a higher E/I balance as a result of iTBS, immediately after stimulation.
Avalanche branching ratio - immediate effects of iTBS versus sham stimulation
Time frame: Change in the avalanche branching ratio recorded during rest, immediately after stimulation, for active versus sham stimulation.
The growth rate of neuronal avalanches can be estimated from the clustering of high amplitude events in in electroencephalography (EEG) signal. Faster growing avalanches correspond with tighter clustering of events in time. Scores range from approximately 0.5 to 1.5 with values below 1.0 indicating inhibition dominance and values above 1.0 indicating excitation dominance. Higher scores, indicating more excitation dominance, are expected following active intermittent theta burst stimulation (iTBS) versus sham stimulation. So, the difference score should be positive, indicating a higher E/I balance as a result of iTBS, immediately after stimulation.
Memory-guided saccade accuracy - effects of cTBS versus sham stimulation
Time frame: Change in degrees of visual angle error estimated 44 minutes after stimulation, for cTBS versus sham stimulation.
Accuracy on the memory-guided saccade task, as quantified by mean degrees of visual angle deviation typically range from ~1.0 to 5.0 degrees, with higher scores indicating higher inaccuracy. Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. Because criticality implies susceptibility and flexibility, stimulation protocols which make the FEF operate closer to criticality, relative to sham stimulation, will show bigger errors in degrees of visual angle.
Memory-guided saccade accuracy - effects of iTBS versus sham stimulation
Time frame: Change in degrees of visual angle error estimated 44 minutes after stimulation, for iTBS versus sham stimulation.
Accuracy on the memory-guided saccade task, as quantified by mean degrees of visual angle deviation typically range from ~1.0 to 5.0 degrees, with higher scores indicating higher inaccuracy. Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. Because criticality implies susceptibility and flexibility, stimulation protocols which make the FEF operate closer to criticality, relative to sham stimulation, will show bigger errors in degrees of visual angle.
Anti-saccade accuracy - effects of cTBS versus sham stimulation
Time frame: Change in percent accuracy estimated 12 minutes after stimulation, for cTBS versus sham stimulation.
Accuracy on the anti-saccade task, as quantified by mean percent of correct saccades away from a cue typically ranges between 80% and 100% correct. Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. Because criticality implies greater inter-regional communication between top-down control regions and sensorimotor cortex, stimulation protocols which make the FEF operate closer to criticality, relative to sham stimulation, will a higher perfect increase in accuracy as a result of stimulation.
Anti-saccade accuracy - effects of iTBS versus sham stimulation
Time frame: Change in percent accuracy estimated 12 minutes after stimulation, for iTBS versus sham stimulation.
Accuracy on the anti-saccade task, as quantified by mean percent of correct saccades away from a cue typically ranges between 80% and 100% correct. Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. Because criticality implies greater inter-regional communication between top-down control regions and sensorimotor cortex, stimulation protocols which make the FEF operate closer to criticality, relative to sham stimulation, will a higher perfect increase in accuracy as a result of stimulation.
Subjective effort discounting - cTBS versus sham stimulation
Time frame: Change in subjective value estimated 72 minutes after stimulation, for cTBS versus sham stimulation.
Subjective values as estimated from an effort discounting procedure as a discounted offer ranging from 0.0 (full effort discounting) to 1.0 (no effort discounting). Lower values indicate that people find subjective effort to be more costly. Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. We hypothesize that divergence from criticality underlies phenomenological effort. So, we predict that stimulation which makes people's brains operate closer to criticality relative to sham will experience less effort and have a higher subjective value.
Subjective effort discounting - iTBS versus sham stimulation
Time frame: Change in subjective value estimated 72 minutes after stimulation, for iTBS versus sham stimulation.
Subjective values as estimated from an effort discounting procedure as a discounted offer ranging from 0.0 (full effort discounting) to 1.0 (no effort discounting). Lower values indicate that people find subjective effort to be more costly. Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. We hypothesize that divergence from criticality underlies phenomenological effort. So, we predict that stimulation which makes people's brains operate closer to criticality relative to sham will experience less effort and have a higher subjective value.
Subjective effort rating - cTBS versus sham stimulation
Time frame: Change in subjective value estimated 70 minutes after stimulation, for cTBS versus sham stimulation.
Likert ratings of subjective effort randing from 1 (low effort) to 10 (high effort). Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. We hypothesize that divergence from criticality underlies phenomenological effort. So, we predict that stimulation which makes people's brains operate closer to criticality relative to sham will experience less effort and have a higher subjective value.
Subjective effort rating - iTBS versus sham stimulation
Time frame: Change in subjective value estimated 70 minutes after stimulation, for iTBS versus sham stimulation.
Likert ratings of subjective effort randing from 1 (low effort) to 10 (high effort). Theta burst stimulation to the FEF should modulate cortical excitability making the FEF in some people's brains operate closer to criticality, and in others' brains, operate farther from criticality. We hypothesize that divergence from criticality underlies phenomenological effort. So, we predict that stimulation which makes people's brains operate closer to criticality relative to sham will experience less effort and have a higher subjective value.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Aug 2024.
- Background: PubMed 15664172Huang YZ, Edwards MJ, Rounis E, Bhatia KP, Rothwell JC. Theta burst stimulation of the human motor cortex. Neuron. 2005 Jan 20;45(2):201-6. doi: 10.1016/j.neuron.2004.12.033.
- Background: PubMed 26850210Chung SW, Hill AT, Rogasch NC, Hoy KE, Fitzgerald PB. Use of theta-burst stimulation in changing excitability of motor cortex: A systematic review and meta-analysis. Neurosci Biobehav Rev. 2016 Apr;63:43-64. doi: 10.1016/j.neubiorev.2016.01.008. Epub 2016 Feb 3.
- Individual participant dataSharing planned: No. All anonymized data will be made publicly available at the conclusion of the trial at Rutgers University's (RUresearch) Data Portal.
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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. This study is not recruiting at the moment.
John A Westbrook, PhD principal investigator
Rutgers 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 transcranial magnetic stimulation in people with Healthy, run by Rutgers, The State University of New Jersey 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 8 inclusion and 10 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: status not confirmed, as of the sponsor's last update on 7 Aug 2024. 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?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact John A Westbrook, PhD (9193605399, andrew.westbrook@rutgers.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Critical dynamics - immediate effects of cTBS versus sham stimulation (time frame: Change in correlations recorded during rest, immediately after stimulation, for active versus sham stimulation.). The study lists 14 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06344559, which also lists 2 linked publications.
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 7 Aug 2024.