During the course of a day, our attention can easily wander from time to time. Our brain can go from focusing on something around us to involuntary, random thoughts for no apparent reason. This “mind-wandering” describes a common phenomenon in which a wide range of self-generated thoughts emerge spontaneously. Neuroscientists have been studying the brain for years as they try to understand where these spontaneous thoughts come from.
Aaron Kucyi, PhD, an assistant professor of psychological and brain sciences in the College of Arts and Sciences, recently published a paper in Imaging Neuroscience where he discussed “brain-triggered experience sampling,” a method that his team in the Dynamic Brain & Mind Lab developed, to learn more about what is happening in the brain when our mind wanders. He spoke with the Drexel News Blog to discuss some of his findings.
Q: What were your main reasons for performing this research?
The experience of “mind wandering” is incredibly common. During mind wandering, you zone out of your immediate surroundings and focus on inner thoughts. Scientists understand very little about what happens in the brain during these moments. That’s partly because it’s very difficult to catch wandering thoughts at the precise times that they occur. We performed this research because we wanted to leverage new advances in real-time neuroimaging to develop a method to accurately catch wandering thoughts as they unfold. That might allow us to better understand how the brain produces different types of spontaneous thoughts, including those that are adaptive (like creative thinking) or maladaptive (like ruminating about negative past experiences).
Another major reason why we performed this research is that neuroscientists have increasingly been studying the “resting state”—what happens in the brain when people simply let their minds wander. It turns out that the brain’s spontaneous activity at rest is extremely organized. Researchers have even proposed that a person’s brain organization at rest could indicate illnesses like depression and anxiety. But interpretation is difficult because we don’t currently understand what components of brain activity at rest are related to ongoing thoughts. With our new real-time neuroimaging method, we wanted to shed light on an important question that has often been overlooked: how do spontaneous events in the brain relate to first-person mental experiences?
Q: What made this study different from previous studies that have been done on this subject?
Previous research on mind wandering has often relied on the experience sampling method. Typically, it involves asking people at random moments what kinds of thoughts they are currently having. By combining experience exampling with neuroimaging methods like functional magnetic resonance imaging (fMRI), scientists can identify correlations between mind wandering and activity in different parts of the brain. However, because people report their experiences at random moments, it has been impossible to determine when a spontaneous thought is initiated and what events in the brain are precisely aligned in time with the beginning of a thought.
Our study was unique because instead of asking people about their thoughts at random times, we selected the moments of experience sampling based on brain activity. In other words, people underwent fMRI while letting their minds wander. As the data streamed in, we rapidly analyzed their brain activity in real time. Whenever we saw an event that was interesting to us, like a blip of activity in a part of the brain involved in emotion, we immediately asked people what they were just thinking about. This allowed us to investigate how certain types of events in the brain are aligned to mental experiences. We call our new method “brain-triggered experience sampling.”
Q: What happens in the brain during these moments of “mind wandering”?
Previous studies show that when people are mind-wandering, the default mode network (DMN) – a specific set of brain regions — activates. So in our study, we monitored activity in a part of the DMN. When a big blip of activity appeared, we immediately asked people whether they were mind-wandering — and they were! This provided a nice validation of our method. It not only verified the role of the DMN in mind wandering but also showed that individual instances of DMN activation were precisely aligned in time with episodes of ‘zoning out.’
But it’s not only about the DMN. We previously showed that different people have a variety of unique experiences during mind wandering, which are reflected in unique patterns of brain activity. So, using our new brain-triggered experience sampling method, we also targeted another part of the brain called the insula, which has been linked to emotion. We thought that this brain region would be associated with moments of high arousal in spontaneous thought. However, our results did not provide support for this idea. Complex experiences involving emotion and arousal likely involve broader coordination of activity across brain regions rather than just activation in one region.
Q: Are there positive and/or negative effects we know about “mind wandering’ and if so what are they?
Yes, both! A common misconception is that mind wandering is all bad. There is increasing evidence that mind wandering after learning something new may actually be beneficial for stabilizing memories. And when you are working on solving a problem but getting stuck, it can sometimes be beneficial to step back and just let your mind wander (think of having an “aha!” moment in the shower). However, zoning out too much – and in the wrong way – can be maladaptive. In conditions like depression and anxiety, moments of mind wandering can turn into prolonged episodes of rumination or worry. In that way, mind wandering is closely tied to mental health.
Q: What are some of the questions you will be looking to answer in future studies?
In the future, brain-triggered experience sampling could be used to study a range of questions in basic science and clinical research: What patterns of brain activity predict the content of spontaneous thought, such as whether a thought is experienced as positive or negative? How do predictive brain patterns change in situations where thought goes awry, such as experiences of rumination and worry in depression and anxiety? In my lab, we are also interested in how the brain and body interact with each other during spontaneous thoughts.
This work was supported by the National Institutes of Health.
Reporters interested in speaking with Kucyi should contact Mike Tuberosa, assistant director, News & Media Relations, at mt85@drexel.edu or 215.895.2705.
