According to Friston's way of thinking, which he calls active inference, the brain is not the body's helmsman or puppeteer, but its dreamer. Brain and body are bound up in a mutual project to predict the world successfully. Sometimes the brain does the work, sometimes the body.

The contents of perception, he argued, are not given by sensory signals themselves but have to be inferred by combining these signals with the brain’s expectations or beliefs about their causes.

There is only one way to interpret your reaction to the altered door: your brain makes low-level sensory predictions about what it expects to see, hear, and feel at every given moment, and it does so in parallel. All regions of your neocortex are simultaneously trying to predict what their next experience will be.