Abstract
In daily life attention is constantly spread not just across computer displays, but across several modalities, tasks, and objects, and it is unclear how attention operates in such realistic situations. Here we report a striking effect of sustained inattentional blindness (SIB) induced by one particularly relevant attention-demanding task: talking on a cellular telephone. Much research has shown that talking on a cellphone will slow responses, increase performance errors, and degrade detailed visual memory. But while some traffic accidents are no doubt caused by such factors, many have a different cause: Why did I hit the the other car? Because I didn't *see* it! Here we report a first test of the impact of cellphone use on visual awareness. Observers viewed a dynamic display containing many moving items with various features, and were given a ‘multiple object tracking’ (MOT) task. Observers completed 3 trials, then on the 4th trial an unexpected event (UE) occurred: a new salient object suddenly entered and passed across the display, fully visible and in motion for 5 s. Observers were then probed in several ways for their awareness of the UE, and as in other studies many observers — 30% — were ‘inattentionally blind’, and completely failed to perceive the UE. Another group of observers completed the identical task, but also had a cellphone conversation with a confederate during the experiment. These observers were no less accurate at the overt MOT task, but their level of SIB skyrocketed to 90%! The nature of this impairment was refined in several additional controls, in which subjects had to talk but not listen to the confederate, listen but not talk, or mindlessly shadow a list of words. The massive jumps in SIB caused by the cellphone conversations and other cognitively engaging controls suggests a sobering conclusion: that visual *awareness* is particularly impaired by cellphone conversations, above and beyond any smaller effects on visual performance.