Creative Fluency is Driven by Default Network Activity
Post by Lincoln Tracy
The takeaway
Creative thinking is a complex and crucial part of the human experience that cannot be linked to one specific area of the brain. Stimulating the brain’s default network - a brain network that is active during activities like daydreaming or mind-wandering - limits creative thinking.
What's the science?
Creative thinking—the ability to produce novel and useful ideas—has been a key evolutionary mechanism underlying the rapid advancement of humans as a species. While certain senses or processes are linked to a specific area of the brain (such as vision with the visual cortex), creative thinking cannot be pinned down to just one area. Previous evidence suggests that connectivity between brain regions associated with the default network may contribute to creative thinking, but no causal relationship has been identified. This week in Molecular Psychiatry, Shofty and colleagues utilized a creative thinking task in the unique environment of awake brain surgery to explore the effects of default network stimulation on creativity.
How did they do it?
The authors recruited 13 patients (three women, age range 19-69 years) with gliomas, a common type of brain cancer. All patients were scheduled for awake brain surgery to remove their tumor. At the beginning of surgery, the left default network was electrically stimulated while patients completed an alternate uses task (AUT), a task commonly used to assess creativity. In this task, patients were presented with a series of everyday objects and asked to list possible alternative uses. For example, a newspaper can be used to swat files, start a fire, or be used for a ransom note. Patients were scored on fluency (the number of alternative uses for each object they could think of) and originality (how many other people suggested the same use). Patients underwent a pre-surgery functional magnetic resonance imaging (fMRI) scan to map their own (individualized) default mode network, which was then stimulated during surgery.
What did they find?
First, the authors sought to validate the AUT in an awake brain surgery setting. Correlating baseline AUT scores with a marker of default network integrity (obtained from the pre-surgery fMRI) revealed a positive correlation for fluency but no correlation with originality. When the authors examined the effect of stimulation on creative thinking during awake brain surgery, they found creative fluency was reduced during default network stimulation. No effect of stimulation on originality was observed. The authors then investigated how stimulating regions associated with the default network affected creativity. Changes in fluency were observed by stimulating the parietal, frontal, and temporal regions of the default network; no effects were observed for originality. Taken together, these findings mean that cortical stimulation impacts creative fluency—but not originality—and that stimulating areas more connected to the default network results in a greater impact.
What's the impact?
This study found a causal link between the default mode network and creative fluency, where direct stimulation disrupted creative fluency. These results imply that different aspects of creativity are controlled by specialized parts of the default network. These findings hint at the possibility of using such a technique to identify and preserve creativity and other cognitive functions of patients undergoing brain surgery.
