Abstract:
Some studies suggest that attention can be captured by irrelevant, salient objects when they appear rarely. We addressed this issue using the N2pc effect, a lateralized, negative voltage spike in the brain potentials in parietal cortex, thought to reflect attentional allocation. A cue display was followed by a target display where participants identified the letter in a specific color. Experiment 1 examined rare, irrelevant color singleton cues (10% of the trials for one color, 10% for the other color, and 80% with no singleton). Despite being rare and salient, these singleton cues produced very little N2pc effect and cue validity effect, indicating little or no attentional capture. Experiment 2 pitted a rare, irrelevant, abrupt onset (appearing on only 20% of the trials) against a target-relevant color cue (appearing on 100% of the trials). Overall, this "relevant" color cue produced N2pc effect and cue validity effects. Most importantly, these effects persisted even when the relevant color cue had to compete with a salient, simultaneous abrupt onset. We argue that salient, irrelevant objects do not necessarily capture attention even when they occur rarely.
