The body influences emotions and the mind through daydreaming
Freely flowing thoughts often pick up signals from the body’s interior. And this appears to have a significant impact on our emotions and, over time, also on our mental health. This is shown by a new international study led by Danish researchers. The scientists behind the study call this previously overlooked phenomenon “body-wandering”.
When boredom sets in or attention drifts, thoughts flow freely and circle around the past and the future, seemingly without any anchor in the physical world. We daydream or “zone out”. In English, this is known as “mind-wandering”. In fact, our thoughts take their own paths for between 30 and 50 per cent of our waking time. And that is a good thing, as mind-wandering is associated, among other things, with creativity and problem-solving.
We know a great deal about daydreaming, but we have misunderstood one aspect. For many years, both in research and more generally, these drifting thoughts have been regarded as being disconnected from the body. However, a brand-new study now reveals that signals from within the body can significantly shape our thoughts.
Based on data from brain scans of more than 500 Danes, an international team of researchers has discovered that freely flowing thoughts, some of the time, revolve around bodily sensations and signals from the body’s organs. A rumbling stomach, a rapidly beating heart, or strained breathing influence our thoughts and also create an emotional response. The researchers call this phenomenon “body-wandering”.
“Our study shows that there is a previously overlooked connection between the brain and the body, which is influenced by emotions, and it even has its own signature in the brain,” says the study’s first author, postdoctoral researcher Leah Banellis from Professor Micah Allen’s research group at the Department of Clinical Medicine at Aarhus University.
Professor Micah Allen is the senior author of the study, which originates from “The Visceral Mind Project”, a unique brain–body data repository that he established with support from the Lundbeck Foundation. “Visceral” refers to the body’s internal systems. Researchers in the project work interdisciplinarily with data-driven methods, brain scans and theoretical modelling, and the aim is to understand how the body influences the mind.
The study has been published in the American journal Proceedings of the National Academy of Sciences (PNAS).
A surprising discovery
The practical part of the study took place in an fMRI brain scanner, where participants lay immersed in their own thoughts for 14 minutes. Immediately afterwards, they were asked questions inside the scanner about their thoughts, feelings and bodily sensations, as well as whether they had symptoms of ADHD and depression.
It turned out that more abstract thoughts were the most common, but thoughts about the body appeared intermittently while participants lay in the scanner. However, there was considerable variation in how often this occurred, and that variation had a surprising significance.
While daydreams were generally associated with positive feelings, participants who thought particularly often about their bodies experienced those thoughts as being linked to negative emotions. In addition, there was increased bodily activity, for example a faster heart rate.
“My expectation was to see an emotional connection, but not in a negative direction. So that was surprising. One might think it was related to the experience of lying in the scanner, but another study without a scanner has since shown the same result,” says Micah Allen.
The surprise grew when the researchers compared responses about emotions with participants’ scores for symptoms related to ADHD and depression.
“Individuals with many body-related thoughts and negative emotions had low scores for symptoms of depression and ADHD, whereas those with few body-related thoughts had high scores,” explains Leah Banellis.
“It may sound paradoxical, but we believe it could be a kind of trade-off: thinking about the body’s signals may feel unpleasant in the moment, but in the long term it provides an advantage,” she says.
Regarding the link to symptoms of ADHD and depression, Micah Allen adds:
“Participants reported whether they had symptoms associated with ADHD and depression. Whether they had a formal diagnosis was not part of the study, as the participants represented a cross-section of the general population. Therefore, our findings do not necessarily correspond to what we would find in people living with diagnosed depression or ADHD. That remains to be investigated.”
Participants were also asked which parts of the body they thought about. It turned out that their thoughts primarily centred on breathing, and they were also preoccupied with bodily movement. To a lesser extent, they thought about individual organs, heartbeats, and activity in the stomach and intestines. The researchers note that the strong focus on movement may be linked to the fact that participants were lying still in a narrow tube.
Brain scans showed that body-wandering has its own distinct signature in the brain. This, too, surprised the researchers, says Micah Allen.
“We did not see much activity in the areas we associate with mind-wandering. So our research suggests that body-wandering is a complementary state to mind-wandering.”
While mind-wandering activates brain regions involved in planning, reflection and other forms of higher-order thinking, body-wandering also leads to activity in networks that monitor signals from the body and regulate levels of alertness or arousal.
Overall, the results suggest that when our thoughts wander, they are far more grounded in the body and shaped by emotions than previously believed. They also indicate that the connections between body and thought are complex and individual.
Leah Banellis sees immediate potential in applying the study’s findings in body-oriented therapy.
“The study shows that individualised therapy is important. People who are already very aware of their bodies risk becoming more anxious and negative if they focus even more on bodily sensations. Conversely, those who are less in touch with their bodies may benefit from tuning in, as they may be at
greater risk of developing depression and ADHD.”
A new chapter
Leah Banellis is currently investigating the interplay between the gut, heart, lungs and brain. Micah Allen is examining, among other things, whether medication can influence communication between the body and the brain, including beta-blockers, which inhibit the effects of stress hormones, and weight-loss drugs containing hormones that affect signalling between the gastrointestinal system and the brain.
Micah Allen explains that the next step will be to uncover the complexity of body-wandering and to investigate variations across populations, cultures, age groups, and in relation to physical and mental health.
The list of possible research topics is long. Among other things, he would like to explore whether it is possible to become stuck in either a mind-wandering or body-wandering state, whether the brain signature of body-wandering can be used as a measure of sensitivity to mental disorders, and whether the connection between body and brain can be regulated through medication, targeted breathing techniques or brain stimulation.
The professor regards the new study as the beginning of a new chapter in the exploration of daydreaming.
“Mind-wandering has been thoroughly studied, and everything we have examined about mind-wandering can now begin to be investigated in relation to body-wandering. We are only just getting started.”