Stable cortical body maps before and after arm amputation

Abstract

The adult brain’s capacity for cortical reorganization remains debated. Using longitudinal neuroimaging in three adults, followed before and up to 5 years after arm amputation, we compared cortical activity elicited by movement of the hand (before amputation) versus phantom hand (after amputation) and lips (before and after amputation). We observed stable cortical representations of both hand and lips in primary sensorimotor regions. By directly quantifying activity changes across amputation, we demonstrate that amputation does not trigger large-scale cortical reorganization. Longitudinal neuroimaging of participants with planned arm amputations shows that the cortical body map remains stable after amputation, with no evidence of hand or face reorganization, thus challenging long-standing theories of brain remapping after limb loss.