Yoga Nidra is a type of guided meditation developed in the 1940s that allows practitioners to enter a deeply relaxed yet conscious state. It works by stimulating the prefrontal cortex through guided meditation to induce beta waves, associated with wakefulness, while the body is relaxed as in sleep. This allows one to gain insight into thoughts, emotions, and subjective experiences to break out of habitual thought patterns. Regular practice has benefits like reducing stress, anxiety and chronic pain, improving sleep and concentration. It has been used successfully by people like Einstein and Napoleon.