Disrupting Fear-based Memory Consolidation

Inclusion Criteria: * Ability to provide informed consent * Willingness to participate in study * No history of musculoskeletal impairment or neurological disease * Clinical diagnosis of PTSD for individuals in the PTSD group. Exclusion Criteria: * Any participant outside the age range * Participants that show signs of dementia (score \< 20 on the Montreal Cognitive Assessment) * Participants that have a history of major head trauma, a neurodegenerative disorder, or recent (\<6 months) substance abuse; * Participants that had a recent history of Central Nervous System (CNS) active drugs that may influence cortical excitability or learning; or * Participants that report contraindications to TMS or MRI - if participating in the TMS/MRI experiments * Current psychoactive medication usage * Current symptoms of psychosis or bipolar disorder (as indicated by study staff through a clinical interview as part of that study). * The study will exclude adults unable to consent, individuals who are not yet adults, pregnant women and prisoners on scientific grounds and to minimize risk.