Philosophers and
scientists have long puzzled over where human imagination
comes from. In other words, what makes humans able to create
art, invent tools, think scientifically and perform other
incredibly diverse behaviors?
The answer,
Dartmouth researchers conclude in a new study, lies in a
widespread neural network -- the brain's "mental workspace"
-- that consciously manipulates images, symbols, ideas and
theories and gives humans the laser-like mental focus needed
to solve complex problems and come up with new ideas.
Their findings,
titled "Network structure and dynamics of the mental
workspace," appear the week of Sept. 16 in the Proceedings of
the National Academy of Sciences.
"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," says lead author Alex Schlegel , a graduate
student in the Department of Psychological and Brain
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."
Scholars
theorize that human imagination requires a widespread neural
network in the brain, but evidence for such a "mental
workspace" has been difficult to produce with techniques
that mainly study brain activity in isolation. Dartmouth
researchers addressed the issue by asking: How does the
brain allow us to manipulate mental imagery? For instance,
imagining a bumblebee with the head of a bull, a seemingly
effortless task but one that requires the brain to construct
a totally new image and make it appear in our mind's eye.
In the study,
15 participants were asked to imagine specific abstract
visual shapes and then to mentally combine them into new
more complex figures or to mentally dismantle them into
their separate parts. Researchers measured the participants'
brain activity with functional MRI and found a cortical and
subcortical network over a large part of the brain was
responsible for their imagery manipulations. The network
closely resembles the "mental workspace" that scholars have
theorized might be responsible for much of human conscious
experience and for the flexible cognitive abilities that
humans have evolved.