A new object captures attention--but only when you know it's new.

Two hypotheses have been advanced to explain why an object appearing suddenly in an empty location captures attention. According to the first hypothesis, the visual transients that accompany an abrupt onset automatically trigger attentional orienting toward the object. The second hypothesis claims that the visual system regards the onset as an advent of a new object, and the latter's novelty causes attention to be drawn toward it. To discriminate between these two accounts, Franconeri, Hollingworth, and Simons (2005) introduced a procedure in which an object was added to the display but, crucially, the object's onset transients were concealed. Their results showed that this additional object failed to capture attention, which they interpreted as evidence against the new-object hypothesis. But the Franconeri et al. procedure could somehow have impeded the visual system from identifying the additional object as new. In three experiments, Franconeri et al.'s results were first replicated and extended. Further, it was shown that when the conditions facilitated the encoding of the locations of the old items, the new object did succeed in capturing attention.