Overview

• Researchers followed three adults with planned arm amputations, scanning them twice pre-surgery and at 3, 6 months and long-term follow-up up to five years, and compared results with chronic amputees and control groups.
• Primary somatosensory and motor cortex representations for the hand and neighboring lips remained stable across time, with no systematic encroachment of facial activity into the deprived hand region.
• Participants could volitionally attempt phantom finger movements that produced stronger brain activity than motor imagery and coincided with residual stump muscle contractions, confirming genuine motor signals.
• Only transient, participant-specific fluctuations appeared in early months after surgery, and these measures returned to typical ranges at later follow-ups.
• Preserved cortical maps support development of brain–computer interface prosthetics and encourage peripheral nerve–targeted interventions for phantom limb pain, though generalization is limited by the small, adult-only longitudinal sample.