The onset of receding motion captures attention: comment on Franconeri and Simons (2003)

Franconeri & Simons (2003) reported that some but not all types of motion capture attention in a visual search task, ostensibly because some types of motion are behaviorally significant. In the present article, we argue that a more parsimonious explanation of their results is that the onset of motion, but not motion per se, captures attention. This conclusion helps to resolve inconsistencies between the Franconeri and Simons findings and earlier reports from other investigators and is consistent with results that we have recently reported (Abrams & Christ, 2003). The Franconeri and Simons interpretation rests largely on their failure to find attentional capture by one type of motion-simulated receding motion. We report here the results of two experiments that demonstrate that the onset of receding motion does indeed capture attention when the motion is produced using stereo depth cues. As we have argued elsewhere, the capture of attention in displays containing motion appears to be dependent on the onset of the motion, rather than on the mere presence of specific types of motion as suggested by Franconeri and Simons. One possible explanation is that the onset of motion captures attention because it serves as a strong cue to animacy--and the detection of nearby animals can have important consequences for survival.