Ones mind processes a visual image and quickly notices any abrupt change within the field of view. This is quite easy and automatic when the image stays put and is continuously visible. However, if the image location changes, or if the image is blanked out briefly and then returns with something changed, one must use their memory of the scene to find the change.
Java Script Version for High Speed Internet Connections:
There are three slide shows of the same sequence of 12 slides.
|Slide show with images interrupted by a black slide. This is the most difficult.|
|Slide show in which the image moves back and forth. This is not quite as hard.|
|Slide show with no interruption and no movement -- this is the easy one!|
Animated GIF Version: Best for Slower Connection Speeds:
There are three slide shows of the same sequence of 12 slides. Each animate gif is a bit larger than 1 MB.
|Slide show with images interrupted by a
white image for 2 seconds. This is the most difficult.
(Alternative version using a sequence of separate web pages. Each frame can be viewed with this version but the loading speed may be too long.)
|Slide show with images interrupted by a black image for 1/10 of a second. This is less difficult.|
|Slide show with no intervening white images -- this is the easy one!|
These pages are modeled after the Exploratorium "Change Blindness" exhibit, which confronts visitors with a normal city streetscape that seems to remain the same except for a persistent steady blinking. (At the Exploratorium site above, click on "Seeing and Attention.")
If you liked this page, check out the Exploratorium's "Don't Forget" page.
Back to Illusions