22 APRIL 13 by PHILIPPA WARR
When we’re scouting round for Important Objects Which We Know Are Around Here Somewhere (if only we could just remember where) the brain activates specific regions to help with the search.
As a result, regions of the brain usually employed in other tasks — recognition of unrelated objects or processing abstract thought — are hijacked for the search mission.
“Our results show that our brains are much more dynamic than previously thought, rapidly reallocating resources based on behavioural demands, and optimising our performance by increasing the precision with which we can perform relevant tasks,” said Tolga Cukur, a neuroscientist at UC Berkeley and lead author of the study published in Nature Neuroscience.
Using functional magnetic resonance imaging (fMRI) the researchers recorded brain activity as participants looked for people or cars in movie clips. The team then compared how much of the cortex was devoted to detecting humans or cars depending on which of the two was the search target.
The results showed that when humans were the target, more of the cortex was allocated to “humans” and when the target was vehicles the cortex prioritised “vehicles”.
“These changes occur across many brain regions, not only those devoted to vision,” said Cukur. “In fact, the largest changes are seen in the prefrontal cortex, which is usually thought to be involved in abstract thought, long-term planning and other complex mental tasks.”
The brain’s flexibility isn’t just a matter of helping you find your car keys or small child faster, though. It means that when you focus on any specific task there is a natural tendency to redistribute neural resources, diverting them from other tasks.
This would help explain why multitasking can sometimes prove so difficult as well as possibly offering future insight into attention-related issues such as ADHD.
Edited by IAN STEADMAN