Brain Imaging and Pain | What fMRI Shows

Published March 4, 2026 · 9 min read

By Tauri Urbanik, Pain Science Researcher

You can literally see it on a brain scan

When someone tells you chronic pain is "all in your head," they're wrong about the implication but accidentally right about the location. Brain imaging technology has made it possible to watch pain happen in the brain in real time. And what researchers see has changed how we understand chronic pain completely.

This isn't theory. It's not a model. It's brain scans showing measurable, objective differences between acute pain, chronic pain, and pain that has resolved after treatment. If you've ever wondered whether neuroplastic pain is "real," brain imaging provides the visual proof.

Acute pain vs. chronic pain: different brain circuits

One of the most important brain imaging discoveries is that chronic pain doesn't just live in the same place as acute pain but louder. It lives in different brain regions entirely.

When you stub your toe, your brain's sensory areas light up. The somatosensory cortex processes the signal. The location, the intensity, the quality. That's acute pain. It makes sense. Something happened to your body, and your brain registered it.

But when pain becomes chronic, something shifts. Research by Hashmi and colleagues tracked back pain patients over a year using repeated fMRI scans (Hashmi et al., Brain, 2013↗). They watched in real time as pain representation moved from sensory circuits to emotional and learning circuits.

Specifically, activity decreased in the somatosensory cortex (sensory processing) and increased in the prefrontal cortex, amygdala, and nucleus accumbens (evaluation, fear, and learning). Chronic pain had literally moved neighborhoods in the brain. It was no longer a sensory experience. It had become a learned emotional pattern.

This is why chronic pain doesn't respond to the same treatments as acute pain. You're not treating a sensation anymore. You're treating a brain pattern.

The brain predicts chronic pain before it happens

Perhaps the most striking brain imaging finding comes from Apkarian's work at Northwestern. His team showed that the structure and connectivity of certain brain regions can predict who will develop chronic pain after an acute injury, before it happens (Apkarian et al., Journal of Neuroscience, 2004↗).

Think about what that means. Two people get the same back injury. Same severity. Same location. One recovers fully. The other develops chronic pain. The difference isn't in their spines. It's in their brains.

Baliki and colleagues expanded on this, showing that brain connectivity patterns at the time of acute injury predicted chronification with significant accuracy (Baliki et al., Nature Neuroscience, 2012↗). The connections between the prefrontal cortex and the nucleus accumbens were particularly predictive. Stronger connectivity meant higher risk of chronic pain.

This research demolishes the idea that chronic pain is simply about tissue damage. If brain structure predicts outcomes better than injury severity, the brain is the primary player.

What the Boulder study brain scans showed

The Boulder back pain trial didn't just measure self-reported pain. It included fMRI scans before and after treatment (Ashar et al., JAMA Psychiatry, 2022↗).

After 4 weeks of Pain Reprocessing Therapy, participants showed reduced activity in brain regions associated with pain processing. The anterior insula and anterior midcingulate cortex, areas that evaluate the emotional significance of pain, showed decreased activation.

This is critical evidence. It means the treatment didn't just change how people talked about their pain. It changed how their brains processed it. Objective, measurable, visible on a scan.

The skeptic's argument, "they just say they feel better," falls apart here. The brain scans show something physically different. The neural patterns changed.

The pain "neuromatrix": it's a network, not a spot

Early pain research tried to find "the pain center" in the brain. A single region responsible for producing pain. That search failed. Because pain doesn't have a center.

Instead, pain involves a distributed network of brain regions working together. Researchers call it the pain neuromatrix or pain matrix. It includes sensory areas, emotional areas, evaluative areas, memory areas, and motor planning areas. Pain is a whole-brain experience.

Tor Wager's work on the neurologic pain signature identified a specific pattern of brain activity that reliably tracks acute pain across individuals (Wager et al., New England Journal of Medicine, 2013↗). This signature can distinguish physical pain from emotional distress, social rejection, and other aversive experiences.

But here's the key finding for chronic pain: the neurologic pain signature is less predictive for chronic pain than for acute pain. That's because chronic pain has shifted to different circuits. It's no longer using the same neural infrastructure as a fresh injury. It's become something else. A learned pattern in emotional and evaluative circuits.

Fibromyalgia: central sensitization visible on scan

Brain imaging has been particularly revealing for fibromyalgia. Patients with fibromyalgia show measurably different brain responses to normal stimuli. Gentle pressure that doesn't activate pain regions in healthy controls produces robust pain-related brain activity in fibromyalgia patients.

This is central sensitization visualized. The nervous system's volume is turned up. The brain is treating normal signals as threats. And you can see it on the scan.

This finding has been important for validation. For decades, fibromyalgia patients were told their pain wasn't real because tests came back normal. Brain imaging showed the opposite. Their pain processing was amplified at the neural level. The pain was real. The mechanism was central sensitization, not tissue damage.

What this means for you

Brain imaging research proves three things that matter for anyone with chronic pain.

First, your pain is real. Brain scans show measurable activity associated with chronic pain. Nobody who understands the neuroscience would say it's imaginary.

Second, chronic pain is a brain phenomenon. It involves emotional and learning circuits, not just sensory processing. This is why stress makes it worse. Why it fluctuates with your mood. Why it responds to fear and attention.

Third, it can change. If pain patterns are visible on brain scans before treatment and those patterns change after treatment, then the brain is plastic. It learned the pain. And it can unlearn it.

A

Alex, 43

chronic pain for 5 years

Alex was a research scientist who demanded evidence. When a colleague mentioned neuroplastic pain, Alex was dismissive. Until he read the brain imaging studies. Seeing that chronic pain literally shows up differently on fMRI than acute pain shifted something for him. His pain wasn't damage. It was a pattern. And patterns, as a scientist, he understood could be changed. That shift in framing, from body damage to brain pattern, was the starting point for his recovery.

Composite story based on common patient patterns. Not a specific individual.

Frequently asked questions

Can brain scans show chronic pain?

Yes. fMRI studies show that chronic pain activates different brain regions than acute pain. Chronic pain shifts from sensory processing areas to emotional and learning circuits. Researchers can see these patterns and even predict who will develop chronic pain based on brain connectivity.

What brain regions are involved in chronic pain?

Key regions include the prefrontal cortex (evaluating threat), anterior insula (interoception), anterior cingulate cortex (emotional response to pain), and amygdala (fear processing). In chronic pain, these emotional and evaluative regions become more dominant than sensory areas.

Does brain-based pain treatment change brain scans?

Yes. The Boulder study (Ashar et al., 2022) showed that Pain Reprocessing Therapy reduced activity in pain-processing brain regions on fMRI. After treatment, participants' brains processed pain signals differently, providing objective evidence that the treatment worked at a neural level.

Can the brain really create pain without an injury?

Brain imaging confirms this. fMRI studies show the brain can generate full pain experiences without any peripheral input. Phantom limb pain, where amputees feel pain in missing limbs, provides the most dramatic evidence. The brain's pain matrix fires without any body signal.

References

1. Hashmi JA, et al. Shape shifting pain: chronification of back pain shifts brain representation from nociceptive to emotional circuits. Brain. 2013;136(Pt 9):2751-68.DOI: 10.1093/brain/awt211
2. Apkarian AV, et al. Chronic back pain is associated with decreased prefrontal and thalamic gray matter density. J Neurosci. 2004;24(46):10410-5.DOI: 10.1523/JNEUROSCI.3623-04.2004
3. Baliki MN, et al. Corticostriatal functional connectivity predicts transition to chronic back pain. Nat Neurosci. 2012;15(8):1117-9.DOI: 10.1038/nn.3153
4. Ashar YK, et al. Effect of Pain Reprocessing Therapy vs Placebo and Usual Care for Patients With Chronic Back Pain: A Randomized Clinical Trial. JAMA Psychiatry. 2022;79(1):13-23.DOI: 10.1001/jamapsychiatry.2021.2669
5. Wager TD, et al. An fMRI-based neurologic signature of physical pain. N Engl J Med. 2013;368(15):1388-97.DOI: 10.1056/NEJMoa1204471