"Our findings move us closer to understanding how the organization of our brains sets us apart from other species and provides such a rich internal playground for us to think freely and creatively," said lead author Alex Schlegel, a graduate student in the Department of Psychological and Brain Sciences.
Scientists have theorized that imagination requires a "mental workspace," or widespread neural network, that consciously manipulates symbols, images and ideas. Evidence for this type of brain activity hasn't been found until now, as most brain activity is studied in isolation.
Researchers asked 15 study participants to imagine things they've never pictured in their mind before, such as a bumblebee with the head of a bull.
Participants imagined abstract visual shapes, and then mentally combined them into more complex figures or dismantled them into separate parts.
Using functional MRI, researchers found that a cortical and subcortical network over a large part of the brain was responsible for manipulating imagined imagery. The network resembles the theorized "mental workspace."
The network covered areas responsible not just for visual process but also attention and executive processes. The mental workspace allows manipulation of concepts but also gives humans the intense focus to zero in on the solution to a problem.
Their findings appear in the Proceedings of the National Academy of Sciences.
"Understanding these differences will give us insight into where human creativity comes from and possibly allow us to recreate those same creative processes in machines," Schlegel said.