Negative priming without ignoring

Negative priming is conventionally defined by slowed responses to a target item that appeared previously as a distractor. As a result, it is widely assumed that negative priming is caused by an act of ignoring. Three experiments are reported in which novel abstract shapes were studied with either “shallow” or “deep” encoding instructions. This study phase was followed by asame-different discrimination task similar to that employed by DeSchepper and Treisman (1996). Same-different discrimination was slower for old than for new target shapes, and this negative priming effect depended on the difficulty of the discrimination task. The results suggest that negative priming may not be caused by the ignoring of a prime stimulus.