Activity in the neurons that responds to injury is called nociception. It allows us to recognise and label different kinds of damaging stimuli, such as slamming your hand in the door or burning it on a stove.

Researchers wanted to observe what happens in the brain when we're exposed to damaging stimuli. They reported a pattern of neural activation across a network of brain regions that tracked nociceptive activity. Surprisingly, neuroscientists also observed this signature in the brain, and patients can report intense pain, without any tissue damage.

Nociception is often a part of the experience of pain, but it is not pain. It is not sufficient nor necessary for pain, for example, when we consider the pain of depression or grief.

So tissue damage can happen without pain, and pain can occur without tissue damage, and nociception that seems like pain isn't pain. This is because our experience of our bodies, perceptions, and explanations of the perceptions is part of a complex network of our nervous system.

Our complex nervous systems continually process and integrate information about the body, regulating and balancing the resources. We respond and adapt to what is happening to us or is expected to happen to us.

We do this by running simulations of information we gathered and stored from past experiences. We can feel the signals of these simulations just as intensely as the signals we get from actual injury. This can be useful as the body can kickstart the circulation of our endogenous painkillers just before the injury happens.

Placebo can be a powerful treatment as it can cause pain relief or therapeutic benefit on the expectation of treatment rather than 'real' treatment.

• Studies show patients expecting morphine increase the circulation of their own endogenous opioids in advance of getting morphine.
• Patients who had undergone amputation can overcome phantom limb pain with mirror therapy. The brain is tricked into thinking their limb is restored and able to move, loosening up the discomfort.

If we received a real injury, it wouldn't disappear because we use the power of positive thinking. Paracetamol does work for pain, and surgical and pharmacological interventions are life-saving and can reduce suffering.

But pain is complex. It is often caused more by what we think and fear, and that means we have more tools at our disposal to deal with it.