Trapped in the Loop: Prediction Errors, Palinopsia, and a Nervous System That Can’t Switch Off

One of the things I was diagnosed with a while back is something called palinopsia. It sounds a bit poetic, doesn’t it? The word comes from Greek:

• “Palin-” meaning again, back, or repeat,

• and “-opsia” meaning vision.

So, palinopsia literally means “seeing again.”

What it means in real life? I would see visual images reappear or linger in my field of vision even after the object was gone. Like a ghost-image that refuses to fade. Think headlights or patterns stuck in your sight long after you’ve looked away. Trippy, unnerving—and, for me, it turned out to be a fascinating metaphor for something deeper going on with my brain.

Image by Jonas KIM from Pixabay

My Brain: A Faulty Fortune Teller?

When I first learned about palinopsia, I thought: Wait… why would my brain keep showing me something that’s no longer there?

Then one day, I was studying the brain and came across the concept of brain prediction errors.

According to modern neuroscience, our brains aren’t just passive receivers of the world—they’re prediction machines. They constantly make guesses about what’s going to happen next, based on past experiences, emotions, and sensory input. Your brain is like that overconfident friend who finishes your sentences—except sometimes it gets it wrong.

And when the brain gets it wrong repeatedly, it creates what’s known as a prediction error.

With palinopsia, it’s like the brain is stuck replaying a visual scene because it expects it to still be there. The visual system can’t update fast enough to match reality. It sees "again" even when it shouldn't.

If you want to dive deeper, the Wikipedia article on predictive coding gives a solid overview of how this works on a neural level.

But here’s where it gets really interesting:

This same idea of faulty predictions might explain not just visual disturbances like palinopsia, but a whole range of debilitating symptoms—internal tremors, dizziness, chronic pain, chronic fatigue, tinnitus, post-exertional malaise, insomnia, hypnagogic hallucinations... the list goes on. In my case, palinopsia appeared alongside a diagnosis of Functional Neurological Disorder (FND), with no structural damage found. That suggests it could be the result of the nervous system misfiring—predicting or processing sensory input incorrectly. And if the brain can mispredict what we see, what if it can also mispredict how we feel in our bodies?

What If My Symptoms Are a Loop of Misinformation?

Let me throw something out there:

What if the body sends out a genuine stress or pain signal—but then the brain keeps predicting that it’s still happening, even when the original trigger is long gone?

And because the nervous system trusts those predictions, it stays stuck in fight-or-flight. The result? Exhaustion. Pain. Dizziness. Light sensitivity. Internal buzzing. And yep—palinopsia.

That’s the thing with these conditions. The symptoms are very real—but the root cause might be a miscommunication between body and brain. A kind of glitch in the feedback loop where the brain gets stuck misinterpreting the signals and keeps the whole system trapped.

In a well-regulated nervous system, it goes like this: Stress → response → recovery. But in a hypersensitive or dysregulated system, that final step—recovery—doesn’t come easily. The brain keeps expecting danger, so it keeps telling the body: Stay alert. Stay tense. Stay sick.

Even when everything’s actually fine.

And every so often, you do start to feel a shift — a “good day,” a glimmer of normal. But it doesn’t take much to tip things back. Even minor exertion can overstimulate the system now. Too much movement. Too much emotion. Too much light or noise. And boom — you’re back in the loop.

The brain starts predicting the crash, the flare, the storm…

It’s like your nervous system has been conditioned to expect chaos — so it keeps recreating it.

Why Flow Helps and Repetition Hurts

I’ve also noticed something that seems to support this: it’s not always the effort behind a movement that makes my symptoms worse — it’s the type of movement.

Repetitive exercises—like dumbbell curls, treadmills, or crunches—leave me worse off. Not always immediately, but later. It’s the post-exertional effect that gets me. It feels like my nervous system can’t shift back into rest-and-digest mode. It’s like it gets stuck in a loop, still predicting stress, still expecting the next rep—even after I’ve stopped moving.

Just like with palinopsia, where I keep seeing something that’s no longer there, this feels like a kind of motor or stress palinopsia—my brain is still reacting to movements that are already over. It’s stuck predicting another rep, another strain, another demand.

But activities that are fluid and unpredictable, like surfing, being out in nature, or even a game of badminton , seem to slip past that “over-prediction” filter. These are what I call flow-based activities—they keep my brain engaged without overwhelming it. They ask the brain to respond in real time, not default to a prediction.

Maybe this is why people with nervous system disorders often do better with practices like yoga, tai chi, or qigong. These movements are varied, mindful, and flexible — a direct contrast to repetitive gym-style routines that may just reinforce the repetition, the expectation.

Just a quick note here: People often say that even fun or flow activities can trigger PEM — and they’re right. I’ll try to explain what I think is going on. In my experience, the exertion alone from an activity can be enough to trigger PEM, because the nervous system still registers that exertion as a form of stress. That’s why progress tends to be slow.

But gradually, the nervous system can begin to react less severely as it starts connecting the dots. Positive emotions and feel-good hormones act as a kind of counterbalance. They won’t eliminate symptoms immediately, but they can soften the impact — making the crash feel less severe relative to the exertion.

With persistence, your nervous system becomes less reactive to exertion. You’re not just telling your nervous system it’s safe — you’re showing it through experience. In time, it begins to associate activity with positive emotions, flow, and feel-good hormones, rather than just with stress.

Autism, Familiarity, and Over-Prediction

There’s something else I want to bring into the conversation — something that often gets overlooked. Many people I’ve connected with who live with FND, fibromyalgia, ME/CFS, PEM, and even Long COVID also happen to be autistic or ADHD. I’m one of them.

And the more I’ve learned about how the brain predicts and processes the world, the more that overlap makes sense.

My autistic brain craves familiarity. It constantly runs through scenarios, predicting what might happen next. I rehearse conversations before they happen, fixate on routines, and can happily loop the same song all day long. Repetition feels safe — grounding. Change, surprise, or uncertainty? Not so much. It’s like my brain is always trying to stay one step ahead — but that constant forward scanning comes at a cost.

Now, some researchers, like Lisa Feldman Barrett, suggest that autistic brains struggle with prediction. But in my experience, it’s almost the opposite: my brain doesn’t under-predict — it over-predicts. It tries to anticipate everything, all the time. And while that still fits within the broader theory of predictive coding, it paints a very different lived picture — one of a brain working overtime to stay safe.

If a healthy nervous system thrives on adaptability, then neurodivergent systems — wired for precision and routine — might struggle to shift gears. When you're constantly over-predicting, it’s harder to come back down after stress. Even when the threat is gone, the brain keeps sounding the alarm. The result? A nervous system that can’t transition from fight-or-flight back into rest-and-digest.

Maybe that’s why autistic people seem more prone to nervous system disorders. Not because our systems are broken — but because they’re incredibly finely tuned. What helps us feel safe in daily life — predictability, routine — might also make it harder to recover when our system gets thrown off course.

And this circles right back to brain prediction errors. The brain keeps saying, “I’m still in danger,” long after the danger has passed — and the body listens, even if it shouldn’t.

From Theory to Practice: Gently Rewiring the Loop

So what do we do with all this?

Well, it’s not something that changes overnight—it certainly hasn’t for me. But little by little, I’ve started to notice some shifts. Here are a few things that have gently helped my system feel safer over time:

First, by recognising that the brain can relearn. Neuroplasticity is real, even when the changes are slow and subtle.

Second, by giving the nervous system new experiences that don’t trigger the old prediction. It needs evidence—real, lived evidence—that not everything leads to danger.

Third, by building in rest, safety, and self-trust. You can’t force the brain to update its patterns. You have to coax it gently. Let it feel safe, seen, and steady.

Fourth, through fluid movement and time in nature. There’s a big difference between movement that feels playful and grounding, and movement that feels like punishment. The body knows the difference—and it remembers.

There are many other tools and techniques I’ve used too—like breathwork, meditation, visualisation, and nutritional support—But that’s a deeper dive than we’ve got space for here.

Final Thoughts: Seeing Again, Feeling Again

This work is tough. I stumble, I struggle—but every day, I try. The brain can change. People recovering from these conditions prove it’s possible.

And for those of us in the neurodivergent community—whose nervous systems simply operate differently—progress is possible too. By understanding our needs and supporting our nervous systems, we can also find ways to improve.

So, whether it’s prediction errors or something else, we keep moving forward—asking questions, exploring new ideas, learning from the science, and growing as we go.

References

🧠 Brain & Predictive Coding

• Predictive coding theory: The brain builds internal models to predict sensory data, updating when prediction errors occur. Wikipedia – Predictive coding

• “Top-down predictions integrate with bottom-up signals … modulated by the predictability of the sensory input.”eLife article on Predictive Coding

• Free Energy Principle: The brain reduces uncertainty by aligning predictions with sensory input. Wikipedia – Free energy principle

  
  

👁️ Palinopsia & Visual Prediction Errors

• Palinopsia is a neurological condition where visual images persist or reappear after the original stimulus is gone. This phenomenon—often described as lingering afterimages—is formally referred to as visual perseveration (Wikipedia – Palinopsia).

• Emerging research suggests that palinopsia may be consistent with predictive coding theory—a framework proposing that the brain constantly generates predictions about sensory input and updates them based on incoming information. When this system fails, prediction errors—the mismatches between expected and actual input—may go unresolved or become exaggerated, leading to perceptual anomalies like palinopsia.

• A recent review of prediction-error mechanisms across brain systems supports this framework, exploring how disrupted or miscalibrated prediction error signals can shape sensory experiences and memory formation (PubMed – PMC11488523).

⚠️ Post-Exertional Malaise (PEM)

• PEM is the hallmark symptom of ME/CFS — worsening of symptoms after minor activity, with delayed onset and prolonged duration. Post-Exertional Malaise Wikipedia – Post-exertional malaise

  
  

🚫 Harm from Structured Exercise (GET)

• Graded Exercise Therapy (GET) was once recommended but many patients report harm.~30–50% of patients report worsening from GET.

  Wikipedia – Graded Exercise Therapy