Project Summary After amputation of an arm or leg, up to 90% of subjects experience a ?phantom limb?, a phenomenon characterized by persistent feelings in the missing limb. Many subjects with a phantom limb experience intense pain in the missing extremity that is often poorly responsive to medications or other interventions. The proposed work aims to serve as ?proof of concept? that PLP may be reduced by high-quality, multi-modal feedback as provided through immersive virtual reality. We will utilize a virtual reality system developed and tested with patients with phantom limb pain in twenty-five subjects with significant PLP of more than 6 months duration. We propose a within-subject, multiple-baseline design in which subjects with PLP will initially perform a distracting VR task lacking the hypothesized ?active ingredients? (visual, auditory and tactile feedback of the leg) for a variable period before receiving the targeted Lower Limb VR intervention. We will assess, on an exploratory basis, whether the effectiveness of virtual reality treatment with multi-modal feedback is related to factors such as ratings of immersiveness or limb control. The investigation is designed to serve as a well-planned stage in the translational pipeline, and will thus provide a critical bridge to developing a large-scale randomized control trial using an optimized treatment.