PLOS One 2024 documents motor recovery in three pigs after spinal transection

The 2024 PLOS One study cut spinal cords in three pigs and applied a polyethylene glycol-based sealant. All animals recovered limited locomotion within weeks. Histology showed axonal regrowth across the lesion but no full tract reconstruction. Courtine at EPFL stated no existing method can restore precise descending control required for head transplant function. White's 1970 rhesus monkey grafts produced eye and mouth movement yet zero limb control after cord severance. Canavero's claims rely on the same sealant data without primate head-to-body controls.

Rothblatt's 2014 mindclone framework requires continuous personal data streams to train autonomous agents. Current large language models trained on social media and diaries produce consistent stylistic output but lack persistent episodic memory or sensory grounding. No public benchmark measures identity continuity across decades of simulated experience. The head transplant route therefore remains the only proposal with an active surgical protocol, yet it collides with the same axonal regeneration limits documented in the pig study.

Operational consequence is continued investment in incremental spinal repair rather than whole-body transfer. Regulators have issued no approvals for human head transplantation. Research groups now track axonal tracer density and motor evoked potential thresholds in large-animal models. If pig-level recovery does not scale to voluntary fine-motor control in primates by 2028, the Canavero protocol will remain classified as non-viable for cognitive continuity.