Jen messaged her closest friend in the afternoon. By evening there was still no reply.

“Is she angry with me? Did I say something that upset her?” The more she thought, the more her stomach turned and her heart raced. She read back through their old messages several times, looking for where she had gone wrong. When her friend replied at nine — “Sorry for the slow reply, it’s been a mad day” — Jen could breathe properly again. What is interesting is that for all those hours, her body had been responding to a possibility her brain had forecast, as though the conclusion that her friend was angry were established fact, when the information in front of her said only that a message had not yet been answered.

One frame first, clearly stated. The idea that the brain is a prediction machine — known in the literature as predictive processing — is a highly influential theoretical framework that accounts for a great many phenomena. But it remains a theory under study and under debate, not a settled account of everything the brain does. In this article we use it as a lens for looking at our own minds, without claiming it is the final word.

In short: predictive processing proposes that the brain uses prior experience to generate predictions about what it is perceiving, then compares those predictions against the incoming sensory information. The difference between the two is called prediction error, which may help the brain adjust its next prediction. This does not mean the brain invents reality wholesale.

What predictive processing proposes

The central idea is that the brain does not sit waiting passively for information from the outside world and then process it afterwards. It works actively, forecasting continuously what is about to happen, and using sensory information to confirm or correct that forecast.

Put simply, what we perceive in any given second is not a straightforward reflection of the world. It is a blend of the information genuinely arriving and what the brain expects to be there, built on prior experience. (You will sometimes see the term predictive coding alongside it — a related term, though occasionally used with a different emphasis.) Many neuroscientists therefore describe perception as the brain’s best guess, constrained by sensory information, rather than a camera’s record of reality. And this is why two people can witness the same event and perceive it quite differently: each has a different store of experience with which to predict.

How the brain uses old experience to forecast

The process relies on two parts working together. The first is the expectation, or model, the brain has built from past experience. The second is the information actually arriving through the senses at that moment. When the two agree, everything runs smoothly. When they do not, what arises is prediction error — a signal telling the brain it is time to revise the model.

In ordinary circumstances this system is enormously useful. It saves us processing everything afresh every second, letting us walk, read or drive fluently without thinking step by step. The difficulty arises when the model the brain predicts with was built from painful experience. Someone rejected repeatedly may have a brain that forecasts rejection by default, and reads a friend’s silence as anger though nothing in the actual information says so — exactly what happened to Jen.

Predictive processing is like autocomplete

Think of the autocomplete on your phone. You have barely begun typing a word and it has already guessed the next one, based on patterns you have typed often before. Most of the time it guesses correctly and speeds you up considerably. That is the useful face of prediction. But we have all met the moment where it guesses comically wrong, because it reached for a word you use frequently rather than the one you intended.

Our brains work in a similar way. They fill the gaps in a situation with predictions drawn from prior experience. Sometimes the guess is accurate and helpful. Sometimes it fills in a meaning that does not match what is in front of us — particularly when the experience it draws on is full of hurt. The good news is that, like an autocomplete that gradually learns a new pattern once you type differently often enough, the brain can adjust an old model through new learning and new experience. How much updating happens depends on how much weight the brain gives the new information, and on whether that new experience occurs consistently in a relevant context. If the brain still treats the new information as an exception, the old model may well persist.

Prediction, anxiety and pain

Once the principle is understood, a good deal about distress begins to make sense. Seen through predictive processing, some forms of anxiety may be understood as a state in which the system gives unusual weight to predictions of danger, so the body prepares to respond before there is sufficient information to confirm anything. The heart thuds, the stomach turns, the muscles tighten, though the feared event has not happened at all. This is a brain whose pattern for forecasting danger has been set unusually sensitive — something that may be influenced by past experience, by learning, and by other factors together, rather than by any single cause.

This is especially clear in the case of pain. Research finds that expectation genuinely affects the perception of pain, as seen in the placebo phenomenon, where expecting improvement is associated with reduced perception of pain. The reverse holds too: forecasting a great deal of pain can increase how much is perceived. None of which means pain is imaginary or all in the head. The pain is always real. It is only that our perception of it is shaped by prediction more than we tend to think.

In some theories of emotion, it has been proposed that the brain uses signals from inside the body, prior experience, and context together to predict and assign meaning to what we are feeling. That idea is influential and explains a good deal, but it is not an account of emotion the field agrees on entirely, and not every school of predictive processing accepts the same conclusions. It is worth holding as an interesting perspective rather than as settled fact.

How hypnotherapy relates to the brain’s predictions

This is a point easily overstated, so it is worth staying strictly with the evidence. Some theoretical models view hypnotherapy and responsiveness to suggestion as related to the brain’s predictive processes, since suggestion, expectation and imagery can influence certain kinds of perception and response. That said, this is one of several frameworks used to explain hypnosis, and it is not a conclusion that all of hypnosis arises from predictive processing alone.

There are a few areas where the research evidence is rather firmer than elsewhere: pain management, and anxiety before a medical procedure — contexts in which expectation, attention, suggestion and the interpretation of experience may all play a part together. Plainly: hypnotherapy is not the deletion of memory, nor the overwriting of reality in the brain at will, and not a special power that changes perception instantly. What can fairly be said is that it may be one context in which a client can practice adjusting expectations and responses, through the brain’s natural mechanisms for learning — and that, like any other change, it still relies on consistent repetition.

At NBRH we work on the principle of Neuro-Behavioral Repatterning & Hypnotherapy: adjusting the nervous system’s patterns of response, and behavior, systematically. Where prediction is concerned, that means one thing above all: patterns of forecast built from prior experience can be revised, gradually, through experience and learning repeated consistently. Lasting care for the mind does not come from ordering the worry to stop this instant. It comes from helping the system build forecasts that are more flexible, more open to new information, and slower to draw their conclusions from old experience alone.

Prediction is only one of the patterns the brain keeps revising — “What Neuroplasticity Is” sets out how that revision happens.

What the Predictive Brain Is: Why We Are Always Anticipating, and How Those Forecasts Shape What We Feel