Where do our minds wander? Brain waves can lead the way

Anyone who has tried and failed to meditate knows that our mind is seldom still. But where do they roam? New research from UC Berkeley has come up with a way to track the flow of our internal thought processes and signal whether our minds are focused, fixed, or wandering.

Using an electroencephalogram (EEG) to measure brain activity while people performed mundane attention tasks, researchers identified signals to the brain that reveal the mind is not focused on the task at hand or wandering around aimless, especially after focusing on a mission.

Specifically, an increase in alpha brain waves was detected in the prefrontal cortex of more than two dozen study participants as their thoughts jumped from subject to subject, providing an electrophysiological signature for spontaneous and unconstrained thinking. . Alpha waves are slow brain rhythms ranging in frequency from 9 to 14 cycles per second.

Meanwhile, weaker brain signals known as P3 have been observed in the parietal cortex, further providing a neural marker when people are not paying attention to the task at hand.

“For the first time, we have neurophysiological evidence that distinguishes different internal thought patterns, allowing us to understand varieties of thought essential to human cognition and to compare between healthy and disordered thinking,” said the lead author of study, Robert Knight, UC Berkeley member. professor of psychology and neurosciences.

The results, published this week in the Proceedings of the National Academy of Sciences journal, suggest that adjusting our external environment and allowing our internal thoughts to move freely and creatively is a necessary brain function and can promote relaxation and exploration.

Plus, EEG markers of how our thoughts flow when our brains are at rest can help researchers and clinicians detect certain thought patterns, even before patients know where their minds are wandering.

“It could help detect and diagnose thought patterns related to a range of psychiatric and attention disorders,” said study lead author Julia Kam, assistant professor of psychology at the University. from Calgary. She initiated the study as a postdoctoral researcher in Knight’s Cognitive Neuroscience Lab at UC Berkeley.

Another co-author of the article is Zachary Irving, an assistant professor of philosophy at the University of Virginia who explored the psychological and philosophical foundations of wandering the mind as a postdoctoral researcher at UC Berkeley.

“If you focus on your goals all the time, you may miss important information. And so, having a free associative thought process that randomly generates imaginative memories and experiences can lead you to new ideas and perspectives, ”said Irving, whose philosophical mind-wandering theory shaped the methodology of study.

Irving worked with Alison Gopnik, developmental psychologist and philosophy specialist at UC Berkeley, who is also a co-author of the study.

“The minds of babies and toddlers seem to be constantly wandering, and so we wondered what functions this could serve,” Gopnik said. “Our article suggests that mental wandering is as much a positive characteristic of cognition as it is an oddity, and explains something we all experience.”

To prepare for the study, 39 adults learned the difference between four different categories of thinking: task-related, free-moving, deliberately constrained, and automatically constrained.

Then, while wearing electrodes on their heads that measured their brain activity, they sat in front of a computer screen and tapped the left or right arrow keys to match the left and right arrows appearing in random sequences on the l ‘screen.

When they completed a sequence, they were asked to rate on a scale of one to seven – whether their thoughts during the task had been task-related, moving freely, deliberately constrained, or automatically constrained.

An example of task-unrelated, free-moving thoughts would be if a student, instead of studying for an upcoming exam, wondered if she had received a good grade for an assignment, then realized that she hadn’t. not cooked dinner yet, and then wondered if she should exercise more and ended up remembering her last vacation, Kam said.

The responses to the thought process questions were then divided into four groups and compared to the recorded brain activity.

When study participants reported having thoughts that moved freely from subject to subject, they showed increased alpha wave activity in the frontal cortex of the brain, a pattern linked to the generation of ideas. creative. Researchers have also found evidence of lower brain P3 signals during off-task thoughts.

“The ability to detect our thought patterns through brain activity is an important step towards generating potential strategies to regulate the flow of our thoughts over time, a useful strategy for healthy and disordered minds,” said Kam.