Head Transplants, Personal Identity and Neuroethics

Abstract

The possibility of a human head transplant poses unprecedented philosophical and neuroethical questions. Principal among them are the personal identity of the resultant individual, her metaphysical and social status: Who will she be and how should the “new” person be treated - morally, legally and socially - given that she incorporates characteristics of two distinct, previously unrelated individuals, and possess both old and new physical, psychological, and social experiences that would not have been available without the transplant? We contend that this situation challenges linguistic conventions and conceptual binaries (“part-whole”), and calls into question the major philosophical approaches to personal identity: animalism and reductionism. We examine these views critically vis-a-vis head transplantation and conclude that they fail to provide an adequate account of the identity of the resultant individual because both neglect the key role of embodiment for personal identity. We maintain that embodiment is central to personal identity and a radical alteration of the body will also radically alter that person, making her a different person. Consequently, a human head transplant will result in an individual partly continuous with the head/brain (in terms of connected memories and mental events), and partly continuous with the body donor (in terms of the inputs and regulatory patterns afforded by the structure and functions of the nervous system, and the self-image of this new embodiment). We conclude that the resultant person would be different from both the individual whose head was transplanted and the one to whose body the “new” head is attached.