Researchers at UC San Diego School of Medicine discovered that movement-triggered pain in chronic low back pain activates the brain's Default Mode Network, a region normally associated with self-reflection and personal identity.
The study, published October 5, 2026, in the British Journal of Anaesthesia, involved 114 patients with chronic low back pain. Researchers used arterial spin labeling, a functional MRI method, to monitor brain activity while participants performed a leg raise test designed to provoke back pain. They also applied harmless heat to the calf to test responses to acute pain.
The findings revealed a striking difference. When movement triggered a chronic back pain flare, the Default Mode Network became more active. When participants experienced the painful heat stimulus, the same network became less active, following the typical brain response to acute pain.
"In every pain study, when you're experiencing pain, the DMN deactivates," said Fadel Zeidan, corresponding author and professor in the Department of Anesthesiology at UC San Diego School of Medicine. "What we show for the first time ever is that when you have a pain flare, it turns on instead. You start to identify the experience with who you are."
The Default Mode Network consists of interconnected regions in the frontal, parietal, and temporal lobes. These areas normally activate during self-reflection and become less active when attention turns outward.
Zeidan noted that the moment-to-moment experience of chronic pain becomes contaminated not only by the feeling of pain but by anticipation of it, recovery from it, memories of previous episodes, and fear of triggering movements.
Because movement-triggered chronic back pain engages different brain networks than acute pain, researchers believe traditional pain treatments may not address processes sustaining chronic pain. Medications like opiates primarily target pain signaling but may not adequately address emotional and personal dimensions.
Zeidan and colleagues are investigating mindfulness meditation and psilocybin as potential treatments. Both approaches aim to change how the brain interprets pain without necessarily eliminating pain signals. Zeidan described mindfulness as cultivating non-judgmental awareness of the present moment and psilocybin as potentially resetting the pain system integrating trauma, past experiences, and future worries.