PKU Researchers Find the Human Brain Flexible in Adapting to New Limbs

Peking University, June 15, 2026: Can humans adopt new limbs? Experiments using modern technology, especially virtual reality (VR), have offered some affirmative evidence. A study recently published in Cell Reports by Professors Bi Yanchao and Wei Kunlin from the School of Psychological and Cognitive Sciences has found that the human brain, through training, can learn to use artificial body parts-virtual wings-skillfully, offering insights into developments in embodied intelligence and physical enhancement.

Background
Over millions of years of evolution, the human brain has developed specialized neural regions for processing the appearance of biological body parts, located primarily in the occipitotemporal cortex (OTC). With the rise of modern technologies such as VR, humans can now experience body forms that have never existed in our evolutionary history, such as virtual, non-human limbs. To explore the neuroplasticity mechanisms behind this phenomenon, the researchers designed a specialized VR training paradigm in which participants controlled the flapping of virtual wings by moving their upper limbs to complete complex flight tasks.

Why It Matters
A long-standing question in cognitive science is how flexible the human brain is when adapting to physical changes that go beyond its evolutionary boundaries. This study offers a compelling answer by demonstrating that the OTC is not limited to representing familiar biological body parts; rather, it possesses the dynamic plasticity to integrate completely foreign, non-human limbs into the body's representational system. Crucially, this cognitive shift does not require millions of years of evolutionary accumulation or lifelong sensorimotor training, reflecting the remarkable flexibility of the human cognitive system.

Key Findings
Throughout the training regimen, which included 4 sessions in 7 days, participants learned to fly in a virtual environment with their arms reimagined as wings. Their arm movements were captured by motion-tracking devices and translated into wing movements that drove changes in altitude in scenes vividly displayed by a VR headset. Crucially, they could only see the wings in the beginning phase, but still established a functional association between their own physical movements and changes in flight altitude. By comparing fMRI data before and after the VR training, the research team discovered that this functional association alone was sufficient to fundamentally alter the brain's neural processing when observing wing shapes. When participants viewed static images of wings, bilateral OTC regions showed stronger category-specific activation, indicating a significantly heightened neural sensitivity to wings as a visual object category.

Furthermore, multivariate pattern analysis (MVPA) revealed that the neural representation pattern of wings in the right OTC became significantly more similar to that of human upper limbs, suggesting that the brain had begun processing wings as a "limb-like" category. Finally, functional connectivity analysis showed that the coupling between the right OTC and the motor-related frontoparietal network exhibited wing-specific enhancement, indicating that the visual representation of wings had become dynamically linked to the body's somatosensory and motor systems.



Future Implications
Ultimately, these findings deepen our understanding of how the brain's neural representations are formed. They offer vital insights for cognitive neuroscience and the future design of embodied intelligence, as well as for expanding human bodily capabilities through physical enhancement devices, wearable robotic prosthetics, and brain-computer interfaces (BCIs).

Written by: Efua Amfo
Edited by: Wang Pincheng, Chen Shizhuo
Source: PKU News (Chinese)