Transcranial Magnetic Stimulation
Conditions
Brief summary
The objective of this study is to examine the effect of transcranial magnetic stimulation (TMS) on the prefrontal cortex and posterior parietal cortex.
Detailed description
The Comprehensive Control Task (CCT) was designed to examine hierarchical control in a single, well-controlled factorial task. On each trial, participants view a letter surrounded by a colored shape at a particular screen location. Color cues the relevant feature, letter or location, for a block of trials. The first trial of a block requires a decision of whether the stimulus is the first position of a circular sequence (sequence start). Subsequent trials require a decision of whether the viewed stimulus follows the previous stimulus in a circular sequence (sequence 1-back). The letter sequence (T-A-B-L-E-T) and spatial sequence (Top-Bottom Right-Left-Right-Bottom Left-Top) are difficulty-matched. Shape cues the task to perform. Squares indicate the standard baseline task, and each block begins and ends with baseline trials. Different shapes indicate sub-tasks. In Switching blocks, shape-switches (e.g. from square to circle or circle to square) cue the sequence start task. Shape-repeats cue the sequence 1-back task. In Planning blocks, triangle shapes indicate that the stimulus can be ignored (automatic "no" response). All the while, the last square-shaped stimulus must be retained as a reference for the next square-shaped stimulus. Finally, in Dual blocks, diamond shapes indicate switching (sequence start) and also planning. The reversion back to square shapes requires sequence matching to the distal, previous square. The design is factorial with stimulus-domain x contextual control x temporal control orthogonally manipulated. Full details of the CCT have been previous described in Nee & D'Esposito, 2016; 2017. The focus in this study will be comparison of FPl-TMS, MFG-TMS, and S1-TMS in an interleaved fMRI-TMS-fMRI design. The logic is to test the apical status of the FPl/MFG through the extent to which TMS impacts other PFC areas and behavior. Each experiment will begin with 1 session of the CCT with fMRI to localize PFC targets. Each participant will then perform 3 counter-balanced sessions wherein a different site will be targeted by TMS followed immediately by fMRI on the CCT.
Interventions
DEVICEtranscranial magnetic stimulation
Transcranial magnetic stimulation delivered to the scalp targeting specific brain structures via stereotactic guidance.
Sponsors
Florida State University
National Institute of Mental Health (NIMH)
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* Between the ages of 18 and 30 * Right-handed * Native English speaker or fluent by the age of 6
Exclusion criteria
* History of psychiatric disorders * History of neurological disorders * Receiving medications for psychiatric or neurological disorders * Familial history of epilepsy * Taking any drugs or medications that are pro-epileptic * Metal anywhere in the head excluding the mouth * Tinnitus * Women who are pregnant
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| PFC-PPC Effective Connectivity | baseline, pre-intervention and immediately after intervention (5 minutes to 1 hour post-TMS) | effective connectivity among areas of the prefrontal and posterior parietal cortex in the blood oxygenation level dependent (BOLD) signal assessed with functional magnetic resonance imaging (fMRI) \[note, this measure has no units, but effective connectivity is a rate measure, so is expressed in Hertz\] |
| PFC-PPC Activation | baseline, pre-intervention and immediately after intervention (5 minutes to 1 hour post-TMS) | blood oxygenation level dependent (BOLD) signal in areas of the prefrontal and posterior parietal cortex assessed with functional magnetic resonance imaging (fMRI) \[note, this measure has no units\] |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Temporal Control Performance (Error Rate) | baseline, pre-intervention and immediately after intervention (5 minutes to 1 hour post-TMS) | behavioral performance (error rate) on conditions involving temporal control in the comprehensive control task |
| Contextual Control Performance (Error Rate) | baseline, pre-intervention and immediately after intervention (t minutes to 1 hour post-TMS) | behavioral performance (error rate) on conditions involving contextual control in the comprehensive control task |
| Temporal x Contextual Control Performance (Error Rate) | baseline, pre-intervention and immediately after intervention (5 minutes to 1 hour post-TMS) | behavioral performance (error rate) of the interaction of temporal and contextual control in the comprehensive control task |
| Temporal Control Performance (Reaction Time) | baseline, pre-intervention and immediately after intervention (5 minutes to 1 hour post-TMS) | behavioral performance (reaction time in milliseconds) on conditions involving temporal control in the comprehensive control task |
| Contextual Control Performance (Reaction Time) | baseline, pre-intervention and immediately after intervention (5 minutes to 1 hour post-TMS) | behavioral performance (reaction time in milliseconds) on conditions involving contextual control in the comprehensive control task |
| Temporal x Contextual Control Performance (Reaction Time) | baseline, pre-intervention and immediately after intervention (5 minutes to 1 hour post-TMS) | behavioral performance (reaction time in milliseconds) on the interaction between temporal control and contextual control in the comprehensive control task |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORDerek E Nee, PhD
Florida State University
Participant flow
Pre-assignment details
After enrollment, participants complete 1) a baseline functional MRI scan to determine targets for transcranial magnetic stimulation, and 2) motor thresholding to determine intensity of transcranial magnetic stimulation. Participants are not assigned to arms if they cannot perform the task inside the MRI scanner (e.g. due to claustrophobia) or if they cannot tolerate transcranial magnetic stimulation.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 39 Participants |
| Age, Continuous | 19.8 years |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 6 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 7 Participants |
| Race (NIH/OMB) Black or African American | 4 Participants |
| Race (NIH/OMB) More than one race | 0 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 | 4 Participants |
| Sex: Female, Male Female | 3 Participants |
| Sex: Female, Male Male | 2 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 37 | 0 / 34 | 0 / 35 |
| other Total, other adverse events | 4 / 37 | 1 / 34 | 0 / 35 |
| serious Total, serious adverse events | 0 / 37 | 0 / 34 | 0 / 35 |
Outcome results
None listed