False memory is a phenomenon where an individual can recall events that did not occur, or recalls them differently from what actually happened. Elizabeth Loftus pioneered research in the field with her famous car crash study. Participants were all shown a video of a car crashing at 20, 30 or 40 miles per hour. In a follow-up questionnaire, respondents were asked "How fast were the cars going when they smashed into each other?" In other variants of the questionnaire, smashed was replaced with hit, bumped, contacted or collided.  Based on the verb, respondents reported the cars hit at varying speeds. When prompted with smashed the car speed was reported as faster than with collided.