THE CAPTURE OF ATTENTION BY ABRUPTLY ONSETTING NEW OBJECTS UNDER CONDITIONS OF UNEXPECTEDNESS AND UNPREPAREDNESS

摘要

The control of attention has to accomplish two aims. First, attention has to be directed to vital events of the environment that are relevant to survival, independently of the current goals. Second, attention has to be maintained in accord with the current task demands. These two types of attention are often referred to as involuntary and voluntary attention. A particular variant of involuntary attention is attentional capture, where attention is involuntarily relocated away from its current focus. One of the proposed conditions for attentional capture has been the presentation of an abruptly onsetting new object. Evidence comes from experiments where task irrelevant onsets that were not predictive of the targeta??s position nonetheless biased attention to their position. Concerns, however, have been raised whether these effects are actually independent from the current task and intentions. The current experiments explore the conditions of onset capture when strategies related to the onset can be excluded with certainty, that is, on the unannounced first presentation. Participants worked on an inefficient visual search task for a while, when in the critical trial, an onset cue was presented either near the target (valid condition) or at distance from the target (invalid condition) without prior warning or information. In the critical trial, large validity effects were observed, which were also found to be stronger than in the post-critical trials, where the non-predictive onsets were repeatedly presented. Further conditions suggest that capture was not due to a general task driven set to detect onsets, and that presenting a new shape (without an onset) does not capture attention. It is concluded that abruptly onsetting new objects pass the test for attentional capture, even when strategies can be excluded by testing their unannounced first presentation.