Neuroplasticity: How the human brain reacts to virtual wings

Chinese neuroscientists wanted to investigate how the occipitotemporal cortex (OTC) adapts to artificial body parts, in this case, virtual wings. This brain region helps the brain, among other things, to recognize seen bodies and body parts as such and to distinguish them from other objects.

For their experiment, the researchers used virtual reality because it can create sensory impressions that break with normal bodily experience. Arm movements were translated into wing movements in the simulation. This created a connection between physical movement, visual feedback, and non-human body shape. The researchers wanted to test whether the brain treats such evolutionarily unusual body extensions at least partially as its body parts. Specifically, they investigated whether the VR experience changes the OTC's reaction to images of wings and what kind of change can be measured.

Study participants learn to “fly”

For their study, the researchers recruited 25 people. All participants completed a total of four VR training sessions within a week. A tracking system recorded arm movements and synchronized them to virtual wings, with which the participants flew through a virtual environment from a first-person perspective.

The training included several flight exercises, including individual wing beats, fast flying, maintaining altitude, and flying precisely through virtual rings. A simplified aerodynamics model ensured that outstretched wings generated lift during the downstroke and retracted wings reduced air resistance during the upstroke.

Before the first and after the last training session, the participants' brain activity was measured using functional magnetic resonance imaging (fMRT). The data were intended to show whether the brain processes wings more like arms after training.

Changes in the brain's body image

The result: After VR training, the activity patterns for wings in the right OTC became more similar to the patterns for upper limbs. At the same time, this brain region was more closely linked to areas processing movement, body position, and touch information when viewing wings. According to the researchers, the virtual wings thus moved closer to the representation of one's own body parts in the brain.

The results demonstrate the suggestive power of virtual reality but also how adaptable the human brain is. “In the future, we may spend a great deal of time in VR. We are very interested in what that could mean for the human brain,” says Kunlin Wei, head of the Motor Control Lab at Peking University and co-author of the study, to Science News.

The work was published in the journal Cell Reports and is freely available online.

(dmk)