Which Face Represents Me? The Neural Responses of a Face Transplant Patient to His Past and Present Face

The study aims to investigate the behavioral and neural responses of a face transplant patient (FTP) to his pre-operative and post-operative faces. For this purpose, a control group (N=15) and a single FTP were presented images of their past face, present face, and other unfamiliar faces and asked to identify whether these faces belonged to them or not. During the task, electrophysiological and behavioral responses were recorded. The FTP exhibited higher N170 amplitudes for his past face compared to the control group, suggesting increased visual processing due to its distinctiveness. N250 latency was shorter for his past face, indicating a profoundly ingrained self-identity. P300 amplitudes to his present face were significantly higher, potentially reflecting cognitive adaptation to his transplanted identity. Behaviorally, the control group identified their past faces more quickly, whereas the FTP demonstrated delayed and less accurate recognition of both his past and present faces. This study presents the first ERP-based comparison of an FTP with a control group, highlighting the dynamic nature of self-face perception and neural plasticity. The findings suggest that self-face identity is a flexible process influenced by past experiences and adaptation mechanisms, offering important implications for rehabilitation and psychological support in face transplantation cases.