Illusory temporal reversal: demo page


General Instructions:  In the next page you will access the actual demo. Before you start, please move your mouse cursor onto the rotating background composed of blue crosses, and click once to make sure that the Flash program is working properly. Your eyes should be at about arm's length (~50cm) from the screen. Fixate your eyes on the white central fixation dot while paying covert attention to the yellow ring in the top-left quadrant. Every once in a while, you will feel that the yellow ring disappears. This is a well studied phenomenon called Motion Induced Blindness. (This is not the illusory effect we want to demonstrate!).

Task Instructions: Now, when the yellow ring disappears from your perception, press any key on the keyboard once, as soon as possible. After a short while (~1/2 second) a small dot will flash inside the ring. In general, this flash will shortly bring back the ring into your awareness. However, ask yourself which one you see first: you may often experience that the ring reappears shortly before the flash! This is the illusory temporal reversal: your brain needs to register the flash before it can bring back the ring into consciousness --then why do you perceive the ring first? (To find out why, please refer to our paper: "The temporal interplay between conscious and unconscious perceptual streams").


Note: You may need to repeat the experiment several times (to get acquainted with Motion Induced Blindness, the keypress procedure and the ensuing flash) before actually experiencing the illusion. In addition, the parameters used in this demo (distance from the screen, delay between keypress and flash) are optimized for an "average" observer, but they may not be ideal (and the effect may not be equally strong) for each individual. (Under the conditions of our experiment, our observers experienced the illusory reversal on 90% of the trials on average).


Ready?

If you have read the above instructions, you are ready to experience the illusion.