Change Detection Ability in Naturalistic Scenes: Are Object Appearances or Disappearances Easier to Detect When Disappearances Should Be More Noticeable?

Onset primacy is a robust phenomenon in which appearance of new objects in a scene effectively captures observers\u27 attention. The present study explored conditions under which object offsets may also capture observers\u27 attention. We hypothesized that our visual attentional system is programmed by default to look for onsets of new objects. However, our attentional priority may be able to flexibly adapt to the detection of object offsets depending on what types of visual event better fulfills observers\u27 behavioral goals. To test this hypothesis, an experiment was conducted in which participants were biased toward finding offset of an existing object. Results suggested that participants who experienced the bias detected offsets more quickly and accurately than participants who did not experience the bias, but still had shorter reaction times and higher accuracy on onset trials. Participants who were free from any biases performed better on onset trials than offset trials. Improved performance on offset trials in participants who experienced the offset bias support the idea that onset primacy may not be a hard-set rule and that observers may be able to give attentional priority to non-onset events in an adaptive manne