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.
