UC Berkeley researchers in neuroscience and philosophy published a study on identifying brain markers of internal thought patterns Monday.
The researchers tracked directed, wandering and “sticky” or obsessive thoughts using electroencephalograms, or EEGs, which are used to map electrical activity in the brain. The study also redefined a previous understanding of mind wandering and could potentially measure how different streams of thought relate to clinical disorders such as ADHD or anxiety.
“Some of these internal thought patterns are off the rails in people with psychological disorders,” said campus psychology and neuroscience professor Robert Knight, who co-authored the study. “The more we understand normal brain processes, the more insight we get into psychological diseases — for instance, depressed and ruminating internal thoughts.”
Study co-authors Zachary Irving and Julia Kam developed the idea for this study at the 2017 summer seminars in neuroscience and philosophy at Duke University.
The research was built off a theory of mind wandering published by Irving in 2016.
“The original definition of mind wandering is all thoughts that aren’t related to the current task,” Kam said. “In our theoretical framework, mind wandering should refer to thoughts that jump from topic to topic.”
Kam added that they were able to quantify and objectively measure the wandering thoughts using EEGs.
The researchers found clear neural signatures of mind wandering and directed thoughts, but they did not find similarly distinct signatures of sticky thoughts. Irving suggested that sticky thoughts may be linked to disorders such as anxiety or depression.
A survey conducted by Irving and campus psychology professor Alison Gopnik found that ordinary people think of mind wandering as dynamic and moving through time — the same way Irving’s new definition does.
“It was really cool for both of us to see that there’s this lay definition of mind wandering that ends up being fruitful in a scientific context,” Irving said. “The folk theory is informing science here.”
A previous version of this article incorrectly attributed a statement that sticky thoughts may be linked to disorders such as anxiety or depression to Julia Kam. In fact, the statement was made by Zachary Irving.