During surgery, a patient awakes but is unable to move. She sees people dressed in green who talk in strange slowed-down voices. There seem to be tombstones nearby and she assumes she is at her own funeral. Slipping back into oblivion, she awakes later in her hospital bed, troubled by her frightening experiences.These are genuine memories from a patient who regained awareness during an operation. Her experiences are clearly a distorted version of reality but crucially, none of the medical team was able to tell she was conscious.
This is because medical tests for consciousness are based on your behavior. Essentially, someone talks to you or prods you, and if you don’t respond, you’re assumed to be out cold. Consciousness, however, is not defined as a behavioral response but as a mental experience. If I were completely paralyzed, I could still be conscious and I could still experience the world, even if I was unable to communicate this to anyone else.