Exposure Therapy and Response Prevention (ERP) is a form of behavior therapy used to treat obsessive compulsive disorder and other recurrent behaviors. Exposure involves imaginary (hidden) or direct (in vivo) controlled exposure to stimuli that cause anxiety. Response Prevention Piece includes training to resist coercion (behavioral response, usually like hand washing). The goal of ERP is to reduce the anxiety caused by provocative stimuli without engaging in the compulsive behavior commonly used to neutralize the anxiety response.