Human Brain Activity
Conditions
Keywords
TMS, BOLD activity, Network activity
Brief summary
This project investigates the effects of repetitive transcranial magnetic stimulation (rTMS) on neural circuits as a function of spatiotemporal parameters and brain state in order to better understand why the method works and how to improve its efficacy. Leveraging our expertise in application of TMS methodology during concurrent single neuron recording techniques in non-human primates and imaging and scalp potential techniques in humans, the investigators aim to resolve three interlocking problems in the design and application of rTMS: stimulation frequency, spatial targeting, and interactions with brain state.
Interventions
DEVICERepetitive TMS
1-10 Hertz rTMS will be administered
Sponsors
Duke University
Study design
Allocation
NON_RANDOMIZED
Intervention model
FACTORIAL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Masking description
Participant is not informed about TMS intensity.
Intervention model description
The study is a within-subjects design focused on estimating the fMRI BOLD response to different levels of TMS intensity. The conditions in the study (arms) are repeated within each participant (20%, 40%, 80%, or 120% of an individual's titrated resting motor threshold).
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
1. Age between 18-30. 2. Use of effective method of birth control for women of childbearing capacity. 3. Willing to provide informed consent.
Exclusion criteria
1. Current or recent (within the past 6 months) of substance abuse or dependence, excluding nicotine and caffeine (urine test). 2. Current serious medical illness (self report). 3. History of seizure except those therapeutically induced by ECT (childhood febrile seizures are acceptable and these subjects may be included in the study), history of epilepsy in self or first degree relatives, stroke, brain surgery, head injury, cranial metal implants, known structural brain lesion, devices that may be affected by rTMS or MRI (pacemaker, medication pump, cochlear implant, implanted brain stimulator); \[TMS Adult Safety Screening (TASS) form\]. 4. Subjects are unable or unwilling to give informed consent. 5. Diagnosed any Axis I DSM-IV disorder (MINI, DSM-IV) 6. Subjects with a clinically defined neurological disorder including, but not limited to: 1. Any condition likely to be associated with increased intracranial pressure 2. Space occupying brain lesion. 3. History of stroke. 4. Transient ischemic attack within two years. 5. Cerebral aneurysm. 6. Dementia. 7. Mini Mental Status Exam (MMSE) score of \<24. 8. Parkinson's disease. 9. Huntington's disease. i. Multiple sclerosis. 7. Increased risk of seizure for any reason, including prior diagnosis of increased intracranial pressure (such as after large infarctions or trauma), or currently taking medication that lowers the seizure threshold. 8. Subjects with cochlear implants 9. Subjects not willing to tolerate the confinement associated with being in the MRI scanner. 10. Women who are pregnant or breast-feeding (urine test). 11. Blindness. 12. Inability to read or understand English.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Motion Perception Accuracy | during each TMS session, up to 3 hours | Acute effect of a rTMS session on the performance for a motion task, as measured by accuracy (in percentage of correct responses) |
| Reaction Time | during each TMS session, up to 3 hours | Acute effect of a rTMS session on the performance for a motion task, as measured by reaction time (in ms) |
| Activation of Cortical Networks During a Visual Motion Task. | during each TMS session, up to 3 hours | Acute effect of a rTMS session on fMRI activation during a motion task, as measured by the change in BOLD signal |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Active rTMS (Repetitive Transcranial Magnetic Stimulation) Repetitive TMS: 1-10 Hertz rTMS will be administered, at varying levels of TMS intensity. | 27 |
| Total | 27 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Participant performance was low | 3 |
Baseline characteristics
| Characteristic | Active rTMS (Repetitive Transcranial Magnetic Stimulation) |
|---|---|
| Age, Continuous | 23.7 years STANDARD_DEVIATION 2.7 |
| fMRI Activity 120% RMT | 1.25 BOLD response STANDARD_DEVIATION 0.15 |
| fMRI Activity 20% RMT | 1.28 BOLD response STANDARD_DEVIATION 0.14 |
| fMRI Activity 40% RMT | 1.28 BOLD response STANDARD_DEVIATION 0.12 |
| fMRI Activity 80% RMT | 1.20 BOLD response STANDARD_DEVIATION 0.14 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 4 Participants |
| Race (NIH/OMB) Black or African American | 2 Participants |
| Race (NIH/OMB) More than one race | 1 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 20 Participants |
| Region of Enrollment United States | 27 Participants |
| Sex: Female, Male Female | 16 Participants |
| Sex: Female, Male Male | 11 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 27 | 0 / 27 | 0 / 27 | 0 / 27 |
| other Total, other adverse events | 0 / 27 | 0 / 27 | 0 / 27 | 0 / 27 |
| serious Total, serious adverse events | 0 / 27 | 0 / 27 | 0 / 27 | 0 / 27 |
Outcome results
Primary
Activation of Cortical Networks During a Visual Motion Task.
Acute effect of a rTMS session on fMRI activation during a motion task, as measured by the change in BOLD signal
Time frame: during each TMS session, up to 3 hours
Population: Within-subjects manipulation (same subjects for each condition).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Dose-response TMS - Intensity = 20%RMT | Activation of Cortical Networks During a Visual Motion Task. | 0.89 BOLD activity | Standard Deviation 0.06 |
| Dose-response TMS - Intensity = 40%RMT | Activation of Cortical Networks During a Visual Motion Task. | 0.87 BOLD activity | Standard Deviation 0.05 |
| Dose-response TMS - Intensity = 80%RMT | Activation of Cortical Networks During a Visual Motion Task. | 0.88 BOLD activity | Standard Deviation 0.06 |
| Dose-response TMS - Intensity = 120%RMT | Activation of Cortical Networks During a Visual Motion Task. | 0.94 BOLD activity | Standard Deviation 0.04 |
Primary
Motion Perception Accuracy
Acute effect of a rTMS session on the performance for a motion task, as measured by accuracy (in percentage of correct responses)
Time frame: during each TMS session, up to 3 hours
Population: Within-subjects manipulation (same subjects for each condition).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Dose-response TMS - Intensity = 20%RMT | Motion Perception Accuracy | 63 Percentage of correct responses | Standard Error 4 |
| Dose-response TMS - Intensity = 40%RMT | Motion Perception Accuracy | 62 Percentage of correct responses | Standard Error 4 |
| Dose-response TMS - Intensity = 80%RMT | Motion Perception Accuracy | 58 Percentage of correct responses | Standard Error 4 |
| Dose-response TMS - Intensity = 120%RMT | Motion Perception Accuracy | 61 Percentage of correct responses | Standard Error 3 |
Primary
Reaction Time
Acute effect of a rTMS session on the performance for a motion task, as measured by reaction time (in ms)
Time frame: during each TMS session, up to 3 hours
Population: Within-subjects manipulation (same subjects for each condition).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Dose-response TMS - Intensity = 20%RMT | Reaction Time | 814 milliseconds | Standard Error 104 |
| Dose-response TMS - Intensity = 40%RMT | Reaction Time | 784 milliseconds | Standard Error 94 |
| Dose-response TMS - Intensity = 80%RMT | Reaction Time | 762 milliseconds | Standard Error 85 |
| Dose-response TMS - Intensity = 120%RMT | Reaction Time | 810 milliseconds | Standard Error 109 |