Have you wondered where imagination comes from, what makes us creative, why we think scientifically or create art, and invent tools? Philosophers have argued for thousands of years about the essence of imagination. Scientists at Dartmouth College believe their study brings us closer to the answer.
According to lead researcher, Alex Schlegel, a graduate student in the Department of Psychological and Brain Sciences, the answer lies in the human brain's "mental workspace", a widespread neural network that coordinates activity across several regions in the brain and consciously manipulates symbols, images, ideas and theories.
The study, which was published in the Proceedings of the National Academy of Sciences, shows how humans are able to focus intensely and rapidly in order to solve complex problems and think up new ideas.
"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.
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."
Proving how imagination occurs is not easy
Researchers have long suggested that human imagination exists thanks to a widespread neural network in the brain.
However, clearly demonstrating that such a "mental workspace" exists has been extremely difficult with available techniques that only managed to examine brain activity in isolation.
How do we manipulate mental imagery?
The Dartmouth scientists approached the issue by asking the question "How does the brain allow us to manipulate mental imagery?"
The authors gave the example of humans being asked to imagine a bumblebee with the head of a bull. Most of us would find the task easy. However, in order to make the image appear in our mind's eye, the human brain has to construct a totally new image, seemingly out of nowhere.
Fifteen volunteers were asked to conjure up in their minds specific visual shapes, and then mentally combine them into more complicated figures. Others had to create complex images in their minds, and then mentally dismantle them into their separate parts.
With the use of fMRI (functional magnetic resonance imaging) the team was able to measure the volunteers' brain activity. What is the difference between fMRI and MRI? - Put simply, MRI looks at the anatomical structure, while an fMRI views the metabolic function. In other words, MRI looks at what is there, while fMRI tells you what is happening there.
Schlegal and colleagues had expected the visual cortex - the part of the brain that processes imagery - to be actively involved in driving mental manipulation. Their study confirmed this, but they also discovered that several other regions appeared to be involved in manipulating imaginary shapes.
Several areas of the brain show differential activity in the study using fMRI
to measure how humans manipulate mental imagery (Credit: Alex Schlegel)
The study confirmed what most scholars had theorized - that the "mental workspace" is responsible for most of human conscious experience and the flexible cognitive abilities we (humans) have evolved.
The team added that further studies are needed to better understand how these neural networks function.
This study shows that when it comes to complex human cognitive behaviors, we need to look at how the brain acts as a whole, rather than its isolated parts.
Imagination affects how we see and hear
How we perceive the world around us is affected by our imagination, to a much greater degree than we perhaps realize, researchers at the Karolinska Institute explained in the journal Current Biology.
Senior author, Christopher Berger, said "We often think about the things we imagine and the things we perceive as being clearly dissociable. However, what this study shows is that our imagination of a sound or a shape changes how we perceive the world around us in the same way actually hearing that sound or seeing that shape does. Specifically, we found that what we imagine hearing can change what we actually see, and what we imagine seeing can change what we actually hear."
The researchers believe their findings may help better understand the mechanisms by which the human brain fails to differentiate thought and reality in schizophrenia and some other psychiatric disorders.