People with chronic low back pain can experience sudden flare-ups during ordinary movements, and new research suggests these episodes engage brain networks linked to a person’s sense of self. A study from the University of California, San Diego School of Medicine found that movement-induced pain activated the brain’s default mode network, or “self-network,” in a way that differs from the response to ordinary acute pain.
Low back pain is the leading cause of disability worldwide, according to the World Health Organization. Pain that lasts longer than 12 weeks is considered chronic, and for many people, everyday activities can trigger sudden increases in symptoms.
The brain has a central role in how pain is perceived, but researchers have had difficulty identifying the circuits involved in chronic pain flare-ups caused by movement. The new findings suggest that persistent back pain may involve more than the processing of physical sensations: It may also become intertwined with identity, memories, expectations and emotional experiences.
Chronic low 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 involving the brain’s default mode network (DMN).
The DMN consists of interconnected regions in the frontal, parietal and temporal lobes. Also known as the “self-network,” it is particularly active when attention turns inward—for example, when people reflect on personal experiences, consider their identity, or think about their thoughts and feelings. The network generally becomes less active when attention is directed toward the outside world.
Researchers found that sudden back pain caused by movement switched the DMN on rather than off. This unusual response suggests that chronic pain may involve brain systems that influence how people experience themselves, not just systems that process bodily signals.
The findings may help explain why treatments focused mainly on controlling pain symptoms do not always provide lasting relief for chronic low back pain. They also raise the possibility that targeting the DMN could offer another therapeutic approach.
Brain scans reveal differences between chronic and acute pain
To study what happens during pain flare-ups, the researchers recruited 114 patients 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 tracks changes in cerebral blood flow. The method measures patterns of brain activity without requiring injected contrast agents.
The researchers also examined participants’ responses to another painful stimulus: a harmless but unpleasant heat sensation applied to the calves, similar to the brief pain of accidentally touching a hot stove.
The two situations produced notably different brain responses. When the leg raise triggered a chronic low back pain flare-up, activity in the DMN increased. When participants experienced the painful thermal stimulus, activity in the same network decreased, matching the brain’s more typical response to acute pain.
The researchers also identified several other patterns:
- Patients 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 areas involved in sensation and movement.
- The increase in heart rate during the test reliably reflected the intensity of the pain flare-up.
Together, the findings provide evidence that recurring chronic pain involves brain processes related to personal identity, rather than simply the detection 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 it can focus on an immediate threat. This response shifts attention away from internal thoughts and toward the external source of danger.
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. Pain may be processed 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 moment when pain is physically present. Concern about the next flare-up, memories of earlier episodes and fear of movements that could cause pain can all become part of everyday 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.
Possible new directions for treatment
Because exercise-induced chronic low back pain involves different brain networks from regular acute pain, the researchers suggest that conventional treatments may not address all the processes that sustain chronic pain.
Drugs such as opiates primarily target pain signaling, but they may not adequately address brain networks involved in the emotional and personal dimensions 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 further research is needed to confirm those findings and establish how effective the 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 the brain’s response to pain?
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 lab is conducting several clinical trials that use 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 restructure brain activity and improve the subjective experience of chronic pain.
The research is still in its early stages, but it offers another way to understand persistent low back pain. Learning why the brain links chronic pain with a person’s sense of self could eventually help scientists develop treatments that address aspects of pain often overlooked by conventional approaches.
Other study authors from the University of California, San Diego School of Medicine include 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
