The reverse of precognition, postcognition is the E.S.P. ability to sense past events by way of the powers of the mind. For example, a person with postcognition may be able to sense what had occurred several days ago or several centuries ago in a particular room. Legitimate scientific studies of postcognition have netted mixed results, not enough to prove or disprove it. However, postcognition remains a popular psionic power in SF.