Exercise-induced flare-ups of chronic low back pain activate the brain’s default mode network (DMN), a system associated with self-reflection and personal identity, according to research from the University of California, San Diego School of Medicine. The finding distinguishes recurrent chronic pain from ordinary acute pain and suggests that persistent back pain may become intertwined with how people think about themselves, their past experiences and their expectations about the future.
Low back pain is the leading cause of disability worldwide, according to the World Health Organization. Pain lasting more than 12 weeks is considered chronic, and everyday movements can trigger sudden worsening in symptoms for many patients.
Although the brain plays a central role in pain perception, researchers have had difficulty identifying the circuits involved in exercise-induced flare-ups.
Chronic back pain activates the brain’s sense of self
The study was published on October 5, 2026, in the British Journal of Anesthesia. It identified an unexpected response in the brain’s default mode network, also known as the “self-network.”
The DMN consists of interconnected regions in the frontal, parietal and temporal lobes. These regions are particularly active when attention turns inward, such as during reflection on personal experiences, identity, thoughts and feelings. They generally become less active when attention is directed toward the outside world.
The researchers found that movement-induced back pain activated the DMN rather than suppressing it. This unusual response suggests that chronic pain involves more than the processing of physical sensations; it may also engage brain systems that influence how people experience themselves.
The findings could help explain why treatments focused primarily on reducing pain symptoms do not always provide lasting relief for chronic low back pain. They also raise the possibility that therapies targeting the DMN could offer another treatment approach.
Brain scans reveal differences between chronic and acute pain
To study the brain during pain flare-ups, the researchers recruited 114 people with chronic low back pain.
Each participant completed a “leg raise test,” a standard clinical procedure used to induce low back pain. During the test, the researchers used arterial spin labeling, a functional MRI technique that monitors changes in cerebral blood flow without injected contrast agents.
The participants also received a harmless but unpleasant heat stimulus on their calves, similar to the brief pain caused by accidentally touching a hot stove.
The two types of pain produced notably different brain responses. When movement triggered a chronic low back pain flare-up, activity in the DMN increased. When participants experienced the painful heat stimulus, activity in the same network decreased, consistent with the brain’s typical response to acute pain.
The researchers also observed several other patterns:
- People with more severe chronic back pain had stronger connections between the DMN and the primary somatosensory cortex, which processes bodily sensations, including signals from the back.
- Greater pain intensity during the leg raise test was associated with increased activity in brain regions involved in sensation and movement.
- Increases in heart rate during the test reliably reflected the intensity of the pain flare-up.
Together, the findings provide evidence that recurrent chronic pain involves brain processes related to personal identity, rather than only the perception of physical pain.
Why chronic pain may produce a different brain response
During ordinary acute pain, the brain typically reduces activity in the DMN so that attention can shift toward an immediate threat. This helps redirect focus from internal thoughts to the potential source of danger.
The exercises that triggered chronic back pain had the opposite effect in the study.
“Every pain study shows that when you’re in pain, the DMN is deactivated,” said corresponding author Dr. Fadel Zeidan, professor of anesthesiology, endowed professor at the Sanford Institute for Empathy and Compassion, and director of the Institute for Pain Health and Mindfulness at the University of California, San Diego School of Medicine. “What we’ve shown for the first time is that when pain flares up, the pain turns on instead. People start to identify with the experience.”
The results suggest that chronic low back pain may be closely connected to the brain’s representation of the self. The brain may process pain not only as a physical warning signal, but also in association with personal memories, expectations and emotional experiences.
For people living with chronic pain, the experience can extend beyond the moments when pain is physically present. Worry about the next flare-up, memories of earlier episodes and fear of movements that might cause pain can all become part of daily life.
“Moment-to-moment experience is contaminated not only by the sensation of pain, but also by anticipation of pain and recovery from pain. It is contaminated by past experiences, such as shame at not being able to participate in normal activities and fear of movement in an attempt to avoid pain.”
This relationship between pain and personal identity may help explain why chronic low back pain can be particularly difficult to treat.
Potential new directions for treatment
Because exercise-induced chronic low back pain engages different brain networks from ordinary acute pain, the researchers suggest that conventional treatments may not address every process that sustains chronic pain.
Drugs such as opiates primarily target pain signaling and may not fully address the brain networks involved in the emotional and personal aspects of persistent pain.
“Current pain medications focus on eliminating a patient’s pain symptoms, but not the cause of chronic pain. These data suggest that chronic pain recurrence also involves a person’s identity.”
The findings point toward treatments that address both the sensation of pain and the relationship between that sensation and the brain.
A recent study by Zeidan and his colleagues examined mindfulness meditation and the psychedelic compound psilocybin. Both approaches have been studied for their potential to help people experience physical pain without closely associating it with their identity. Early results suggest that changing this relationship may reduce pain intensity, but additional research is needed to confirm the findings and determine how effective these treatments are.
“This kind of mind-body medicine or psychedelic medicine approach targets the whole person,” Zeidan says. “Mindfulness is a meditation technique aimed at cultivating a non-judgmental awareness of the present moment that dramatically reduces pain in a very unique way. Psilocybin appears to reset the pain system that integrates trauma, past experiences, and future worries, facilitating a reboot when needed. They are not a silver bullet. They do not necessarily eliminate pain, but they change your relationship with that pain so that it no longer contaminates your daily life.”
Can mindfulness and psychedelics change pain perception?
Rather than attempting to eliminate every pain signal, these approaches aim to change how the brain interprets and responds to pain.
Mindfulness meditation encourages people to observe thoughts, emotions and physical sensations without immediately judging or reacting to them. Psilocybin is being studied for its potential to alter brain processes that connect pain with previous experiences, psychological distress and expectations about the future.
The goal is not necessarily to eliminate pain completely, but to reduce its effects on a person’s thoughts, emotions and daily life.
Zeidan’s laboratory is conducting several clinical trials using brain imaging to investigate whether mindfulness meditation and psychedelic treatments can alter the neural processes involved in introspection. The researchers hope to determine whether these approaches can change brain activity and improve the subjective experience of chronic pain.
The research remains in its early stages. However, the findings offer another way to understand persistent low back pain: by examining how the brain links pain with a person’s sense of self. That perspective could eventually help researchers develop treatments addressing aspects of chronic pain that traditional approaches may overlook.
Other study authors from the University of California, San Diego School of Medicine are Morgan Gianola, Jon Dean, Conan Chen, Daniel Barrows, Gabriel Reigner and Thomas Liu.
Funding was provided in part by the National Institutes of Health’s National Center for Complementary and Integrative Health through grant #R01AT009693 and by the Sanford Institute for Empathy and Compassion at the University of California, San Diego. The researchers reported no conflicts of interest.
Source: www.sciencedaily.com