The display below is an interactive demonstration of apparent
By clicking on the buttons you can change this display
in countless ways. Each click on the SLOW button makes the lines
stay on a little longer. Each click on the FAST button makes the
lines stay on a little shorter. The ISI_PLUS increases the time between
the appearance of lines. The ISI_MINUS decreases the time between
the appearance of lines. The LENGTHEN button makes lines bigger,
and the SHORTEN button makes lines smaller. The CLOSER button brings
the lines closer, and the FARTHER button moves them farther away.
The COLOR button randomly changes the colors of the lines. The RESET
button gives back the original display. There are also buttons to
rotate the lines clockwise and counterclockwise. You can now experiment
and see for yourself how your perception changes as you click on these
buttons. To find out more about how you see this illusion and other
illusions, see the book Visual
Intelligence, by Donald D. Hoffman.