Repetition blindness

Repetition Blindness (RB) is a phenomenon observed in Rapid Serial Visual Presentation. Subjects are less likely to detect the repetition of a target stimulus than they are to detect a second, different target.

For example, a subject's chances of correctly reporting both appearances of the word "cat" in the RSVP stream "dog mouse cat elephant cat snake" are lower than their chances of reporting the third and fifth words in the stream "dog mouse cat elephant pig snake".

The precise mechanism underlying RB has not been conclusively explained, but Nancy Kanwisher has argued that it involves failure to tokenise the second appearance of a repeated stimulus, leading to the second appearance being dropped from short term memory before it can be reported.