Participants will undergo a Functional magnetic resonance imaging (fMRI) scan while performing a fear conditioning/extinction task at the Center for Systems Imaging- Emory University Hospital (CSI-EUH) and then either stay at CSI-EUH or relocate to the Neural Plasticity Research Laboratory at Emory Rehabilitation Hospital. Participants will then be randomly assigned to either receive active or sham continuous theta burst stimulation (cTBS) to transiently disrupt neural activity in the targeted sensory cortex region specifically during the sensory memory consolidation window.

Participants will undergo a Functional magnetic resonance imaging (fMRI) scan while performing a fear conditioning/extinction task at CSI-EUH and then either stay at CSI-EUH or relocate to the Neural Plasticity Research Laboratory at Emory Rehabilitation Hospital. Participants will then be randomly assigned to either receive active or sham continuous theta burst stimulation (cTBS) to transiently disrupt neural activity in the targeted sensory cortex region specifically during the sensory memory consolidation window.

cTBS, a patterned form of TMS, (80% active motor threshold intensity, 3 pulses at 50Hz, 200ms interval, 600 pulses, 40s duration applied over the targeted sensory cortical region using real-time neuronavigation to focally and transiently inhibit neural activity

Preprocessing of neuroimaging data will be conducted using fMRI prep. Pre-processed neuroimaging data will undergo first and second level modeling in Statistical Parametric Mapping. First level analysis include an event-related model with the onset and duration of each event included for each condition, and motion included as a regressor. A high-pass filter of 128s will be applied to account for low-frequency drifts. Amygdala regions of interest (ROIs) will be defined anatomically using California Institute of Technology (CIT168) Subcortical Atlas. Primary sensory cortex ROI & seed coordinates will be defined utilizing voxels within a V1 region mask showing maximal functional connectivity with the amygdala during conditioning.

Preprocessing of neuroimaging data will be conducted using fMRI prep. Pre-processed neuroimaging data will undergo first and second level modeling in Statistical Parametric Mapping. First level analysis include an event-related model with the onset and duration of each event included for each condition, and motion included as a regressor. A high-pass filter of 128s will be applied to account for low-frequency drifts. Whole-brain analysis of changes in local regions of activity will be measured by change in blood-oxygen-level-dependent (BOLD) signal from resting activity. Multiple comparisons using permutation-based methods to control the false positive rate to p<.05.

Skin conductance response (SCR) will be recorded during localization, conditioning, and fear retention tasks using the BIOPAC system MP150 (BIOPAC systems, Inc.) and parameters previously utilized in the lab. SCR is a validated physiological measure of sympathetic arousal, with higher SCR indicating a higher arousal response to conditioned stimuli. Change in SCR from early to late extinction is our primary indicator of the degree of extinction learning. SCR will be scored as a response to individual Conditioned Stimulus (CS)+E and CS- stimuli (maximum SC within 6 seconds post-CS onset, minus average SC over a 2-second prestimulus baseline) and will be square-root transformed for normalization. Early fear extinction will be defined as occurring within the first fear extinction run, with late fear extinction being defined as the second extinction run.