Micro-expressions are brief, nonverbal facial contortions that reveal a person’s emotions and intentions. Micro-expressions last for only a fraction of a second and often go unnoticed by the average person. In mentalism, understanding and interpreting micro-expressions can be used to create the illusion of mind reading or clairvoyance.
“Mentalists and psychics notice ideomotor responses, and even micro-expressions, to help them gain insights into their clients’ thoughts and feelings.”