From change blindness to choice blindness

The phenomenon of change blindness has received a great deal of attention during the last decade, but very few experiments have examined the effects of the subjective importance of the visual stimuli under study. We have addressed this question in a series of studies by introducing choice as a critical variable in change detection (see Johansson, Hall, Sikstrom, & Olsson, 2005, Johansson, Hall, Sikstrom, & Tarning, 2006). In the present study, participants were asked to choose which of two pictures they found more attractive. For stimuli we used both pairs of abstract patterns and female faces. Sometimes the pictures were switched during to choice procedure, leading to a reversal of the initial choice of the participants. Surprisingly, the subjects seldom noticed the switch, and in a post-test memory task, they also often remembered the manipulated choice as being their own. In combination with our previous findings, this result indicates that we often fail to notice changes in the world even if they have later consequences for our own actions.