Toward a neurobiology of personal identity

Because mental experiences derive from the brain, it has long seemed likely that neuroscientists could make progress in understanding the neural basis of specific mental experiences. In this chapter, we review three approaches to advancing our knowledge of how and which brain structures and functions might contribute to the experience of individual or personal identity. One approach, neuropsychiatry, is clinical and is derived from "accidents of nature," that is, injuries to and diseases of the brain. The second approach, experimental neuropsychology, stems from the study and manipulation of normal (intact-brain) and brain-injured individuals. The third, developmental psychology, is both descriptive and experimental and primarily uses information gathered from the study of normal infants, although some data from adults and from individuals with impaired function are also cited. Such approaches can illuminate plausible central nervous system underpinnings of an experience such as personal identity, but they are unlikely to explain the construct and experience as a whole. Whether other approaches, in addition to these, can do so is beyond the scope of this chapter, but concepts.