Biofeedback
Short definition
Biofeedback is a technique that measures body signals, such as heart rate, breathing or muscle tension, and shows them to the person in real time so they can learn to regulate them.
In plain language
The person sees or hears the signal and tries ways of changing it, for example by breathing more slowly. In virtual reality, the signal can change the environment itself, such as a landscape that grows calmer as breathing slows. It is used in relaxation, stress management and rehabilitation, usually with a professional's guidance.