Once you have acquired these skills, they can be used in many different careers. However, you can learn detection skills by training with our Micro Expressions Training Tools. You can read more about the science of Lie to Me. Micro expressions can occur as a result of conscious suppression or unconscious repression, revealing a person's true emotions they may not be aware of or are trying to hide. They are so quick that they're usually missed altogether, but you can train yourself to be able to spot them. Yes, they are! Micro expressions are very brief facial expressions of emotion, lasting only a fraction of their usual duration (half a second or less).