Change Blindness - Psychophysics Lab

Background

Change blindness is the surprising failure to detect large changes in a visual scene when the change coincides with a brief disruption — such as a blank screen, eye movement, or film cut. Rensink, O'Regan & Clark (1997) developed the flicker paradigm: an original and modified image alternate with a brief gray blank between them.

Why It Happens

Without the transient signal that normally draws attention to changes, focused attention is required to detect them. This demonstrates that we do not have a detailed internal representation of the entire scene — only the parts we attend to.

Your Task

Scenes will flicker between two versions with a brief blank. One object in the scene changes (color, position, or disappears). Click on the changing object as fast as you can. Some changes are easy, others take many seconds to find.

References

Rensink, R.A., O'Regan, J.K., & Clark, J.J. (1997). To see or not to see: The need for attention to perceive changes in scenes. Psychological Science, 8, 368–373.
Simons, D.J. & Levin, D.T. (1997). Change blindness. Trends in Cognitive Sciences, 1, 261–267.
O'Regan, J.K., Rensink, R.A., & Clark, J.J. (1999). Change-blindness as a result of “mudsplashes.” Nature, 398, 34.

Change Blindness (Flicker Paradigm)

A scene made of colored shapes will flicker on screen. Between flickers, one object changes (its color, position, or it appears/disappears).

Click on the changing object when you spot it.

The scene flickers: Original (250ms) → Blank (250ms) → Modified (250ms) → Blank (250ms) → repeat.

Each trial has a 45-second time limit. There are 8 trials. Some changes are very hard to find — that's the point!

Change Blindness (Flicker Paradigm)

Your Results