Attention is not a that can be widened; it is a budget that must be spent somewhere.
Attending to one thing is therefore not merely a choice to look at it but a choice not to see others.
Observers counting passes in a video routinely fail to notice a person in a gorilla suit walking through the scene.
They are not ; they are attending, which is precisely why they miss it.
The finding is usually reported as a and has consequences in every setting where somebody is watching for something specific.
searching for lung miss other at rates that surprise them.
Security told to look for one category of object detect others less well.
In both cases performance on the assigned task is excellent, which is what makes the problem invisible.
Nobody notices what a highly competent observer did not see, including the observer.
Remedies that work do not ask people to attend more broadly, which is not something a person can do.
They change the task so that a second pass is made with a different instruction.
A radiologist asked, in a separate reading, to look for anything unexpected finds a proportion of what was missed.
The second reading takes minutes and is resisted because the first reading felt complete.
The feeling of completeness is generated by the task, not by the image.
That is the hardest part of the finding to convey to anybody who is good at their job.
increases the effect rather than reducing it, because experts search more efficiently.
An efficient search is one that spends nothing on regions unlikely to contain the target.
Everything that is elsewhere is therefore exactly what an expert is trained not to look at.