London: Scientists at the University of California, Berkeley, have discovered that when we embark on a targeted search, various visual and non-visual regions of the brain mobilize to track down a person, animal or thing.
That means that if we`re looking for a youngster lost in a crowd, the brain areas usually dedicated to recognizing other objects, or even the areas attuned to abstract thought, shift their focus and join the search party. Thus, the brain rapidly switches into a highly focused child-finder, and redirects resources it uses for other mental tasks.
"Our results show that our brains are much more dynamic than previously thought, rapidly reallocating resources based on behavioral demands, and optimizing our performance by increasing the precision with which we can perform relevant tasks," said Tolga Cukur, a postdoctoral researcher in neuroscience at UC Berkeley and lead author of the study.
The findings help explain why we find it difficult to concentrate on more than one task at a time. The results also shed light on how people are able to shift their attention to challenging tasks, and may provide greater insight into neurobehavioral and attention deficit disorders such as ADHD.
These results were obtained in studies that used functional Magnetic Resonance Imaging (fMRI) to record the brain activity of study participants as they searched for people or vehicles in movie clips.
The findings build on an earlier UC Berkeley brain imaging study that showed how the brain organizes thousands of animate and inanimate objects into what researchers call a "continuous semantic space."
Those findings challenged previous assumptions that every visual category is represented in a separate region of visual cortex. Instead, researchers found that categories are actually represented in highly organized, continuous maps.
The latest study goes further to show how the brain`s semantic space is warped during visual search, depending on the search target.
The study will be published in the journal Nature Neuroscience.