Testing a Neurocognitive Model of Distancing Using Transcranial Magnetic Stimulation.

Study Overview
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Brief Summary
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Distancing oneself from a current distressing situation is a mental skill that can help people to manage their emotions. However, little is known about how distancing works in the brain. Recently developed tools in neuroscience that can modify brain activity might be able to make distancing more or less effective. In doing so, the results could lead to a better understanding of the cognitive processes and neural circuits that support distancing as a form of emotion regulation. If successful, this research may lead to the development of new treatments to help those who suffer from stress-related disorders, such as anxiety and depression.

Detailed Description
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Distancing is an emotion regulation skill that relies in part on self-projection, or the ability to shift perspective from the here and now to a simulated time, place, or person. Based on prior review and meta-analysis of the distancing literature, a new model has been developed of the neurocognitive processes that support distancing. The proposed experiment will test the model causally through a neural intervention that should impair or enhance the ability of healthy adults to successfully apply distancing to down-regulate negative affect. In the model, it is hypothesized that the temporoparietal junction (TPJ) was a key region mediating the self-projection aspect of distancing. Leveraging recent functional magnetic resonance imaging (fMRI) work, the experiment will functionally modulate this region through inhibitory transcranial magnetic stimulation (TMS) to test its causal role in distancing. Importantly, the proposed work shifts emphasis from traditional models of emotion regulation, which implicate frontal executive control mechanisms, to new cognitive processes and brain targets that can ultimately lead to novel approaches to treat affective disorders.

Official Title
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Testing a Neurocognitive Model of Distancing Using Transcranial Magnetic Stimulation.

Conditions
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Emotion Regulation, Real Versus Sham Transcranial Magnetic Stimulation (TMS)

Intervention / Treatment
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* Device: Transcranial magnetic stimulation task
* Device: Sham transcranial magnetic stimulation task


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 18-39 years inclusive Willing to provide informed consent English speaking Signed HIPAA authorization Exclusion Criteria: Current or recent (within the past 6 months) substance abuse or dependence, excluding nicotine and caffeine (assessed via urine test). Current serious medical illness (assessed via self report). 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 TMS or MRI (pacemaker, medication pump, cochlear implant, implanted brain stimulator) [assessed via TMS Adult Safety Screening form]. Subjects are unable or unwilling to give informed consent. Diagnosed any Axis I Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) disorder (assessed via self report). Subjects with a clinically defined neurological disorder (assessed via self report) including, but not limited to: Any condition likely to be associated with increased intracranial pressure Space occupying brain lesion. History of stroke. Transient ischemic attack within two years. Cerebral aneurysm. Dementia. Parkinson's disease. Huntington's disease. Multiple sclerosis. 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 (assess via self report). Subjects not willing to tolerate the confinement associated with being in the MRI scanner. Women who are pregnant or breast-feeding (assessed via urine test). Blindness. Inability to read or understand English. Intracranial implants, such as: Cochlear implants; Aneurysms clips; Shunts; Stimulators; Electrodes; Cardiac pacemakers; Vagus Nerve stimulation devices.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 39 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Transcranial magnetic stimulation (TMS), then Sham TMS.<br>Experimenters will employ a continuous theta-burst stimulation (cTBS) sequence using a figure-8 coil positioned tangentially to the scalp over the target coordinates. Experimenters have defined the target coordinates for stimulation (Montreal Neuroscience Institute coordinates -53, -53, 23) based on peak objective distancing activation in the left temporal parietal junction (TPJ) in previous fMRI studies using the same task. Thirty minutes after stimulation, experimenters will employ a sham version of the TMS intervention where subjects will receive a small electrical stimulation on the scalp via two small electrodes in conjunction with a TMS coil activation. The TMS coil will be reoriented to stimulate into the air away from the scalp, simulating traditional TMS, without inducing any current to the subject. | Device: Transcranial magnetic stimulation task<br>* Experimenters will employ a continuous theta-burst stimulation (cTBS) sequence using a figure-8 coil positioned tangentially to the scalp over the target coordinates. Experimenters have defined the target coordinates for stimulation (Montreal Neuroscience Institute coordinates -53, -53, 23) based on peak objective distancing activation in the left temporal parietal junction (TPJ) in previous fMRI studies using the same task.<br>* Other names: TMS;|
| Sham Comparator: Sham TMS, then Transcranial magnetic stimulation (TMS)<br>Experimenters will employ a sham version of the TMS intervention where subjects will receive a small electrical stimulation on the scalp via two small electrodes in conjunction with a TMS coil activation. The TMS coil will be reoriented to stimulate into the air away from the scalp, simulating traditional TMS, without inducing any current to the subject. Experimenters have defined the target coordinates for the stimulation (Montreal Neuroscience Institute coordinates -53, -53, 23) based on peak objective distancing activation in the left temporal parietal junction (TPJ) in previous fMRI studies using the same task. Thirty minutes post sham stimulation, experimenters will employ a continuous theta-burst stimulation (cTBS) sequence using a figure-8 coil positioned tangentially to the scalp over the target coordinates. | Device: Sham transcranial magnetic stimulation task<br>* A sham version of the TMS intervention where subjects will receive a small electrical stimulation on the scalp via two small electrodes in conjunction with a TMS coil activation. The TMS coil will be reoriented to stimulate into the air away from the scalp, simulating traditional TMS, without inducing any current to the subject.<br>* Other names: Sham TMS;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Self-reported Valence (Distancing) From Baseline to 30 Minutes Post Stimulation. | Valence is how positive or negative a subject feels. Subjects will be asked to rate how they feel on a 7 point Likert scale ranging from 1 (very negative) to 7 (very positive) after using an emotion regulation technique (distancing) when shown graphic stimuli. | baseline, 30 minutes post stimulation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Self-reported Effort (Distancing) From Baseline to 30 Minutes Post Stimulation. | Effort is how difficult it was for a subject to use a specific emotion regulation technique. Subjects will be asked to rate how much effort they felt they used on a 7 point Likert scale ranging from 1 (very little effort) to 7 (very high effort) after using an emotion regulation technique (distancing) when shown graphic stimuli. | baseline, 30 minutes post stimulation |