The Illusory Flash (VIDEO) California Institute of Technology This video is under embargo. Please login to access this video. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Caption This audio and visual illusion illustrates the phenomenon of postdiction: when a stimulus presented later in time affects the perception of a stimulus presented earlier. In this case, a rapid series of beeps and flashes leads the brain to believe it perceived a flash when in fact there was not one. Credit Caltech / Shimojo laboratory Usage Restrictions must use video credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.