Deep brain stimulation (DBS) is a surgical procedure used to treat several disabling neurological symptoms, most commonly the debilitating motor symptoms of Parkinson's disease (PD), such as tremor, rigidity, stiffness, slowed movement, and walking problems. Among the potential side effects of DBS, however, are changes to one's “personality, mood, behavior, or cognition.” This has led to concerns that DBS might threaten personal identity. Examining different views of personal identity can help us understand