Or in other words: to focus on what is most important.
An experiment performed at the University of Rochester confirmed previous findings of more intelligent people (measured by IQ) being more able to correctly identify in which direction moving bars drifted at the center of a screen. However they also made a new discovery: high IQ people were less able than lower IQ-scoring individuals to correctly identify this movement when the bars occupied all the screen, contrary to expectations.
They suspect that this makes sense after all, because it may reflect an ability of more intelligent people to suppress peripheral information to the benefit of their focus, having a less noisy mental processing overall.
Other tested sensory measures such as color discrimination have produced only lower correlation scores.
Source: Science Daily.
Ref. Michael D. Melnick, Bryan R. Harrison, Sohee Park, Loisa Bennetto, Duje Tadin. A Strong Interactive Link between Sensory Discriminations and Intelligence. Current Biology, 2013; DOI: 10.1016/j.cub.2013.04.053