Brain Stimulation and Identity

This chapter reflects on the impact of brain stimulation on identity. Following substantial advances in our understanding of the brain, surgeons and neuroscientists have been able to develop powerful new medical interventions that aim to treat disease by modifying electrical activity in the brain. At present, Deep Brain Stimulation (DBS) is the most precise tool that we have at our disposal in this regard; it can target a cubic millimeter of brain tissue. In terms of precision, it stands in stark contrast to drugs that influence brain activity by affecting neurotransmitters across the brain. However, despite its precision, in some rare cases, DBS can have unintended side-effects, including behavioural and emotional changes. The possibility of controlling motivational and emotional states has intrigued scientists since the earliest days of invasive neurostimulation. This prospect raises profound ethical questions, regardless of whether such changes are intentional or an unintended side-effect of treatment. To what extent does it make sense to say that a medical intervention like DBS can change the recipient into “a different person”? The chapter then turns to concepts in moral philosophy, considering the nature of identity and the self.