How mental predictions shape our perceptions
I recently listened to a very interested TED talk given by neuroscientist, Anil Seth, that contains very salient points for chronic spine pain sufferers. Bear with me at first to review the research.
He makes the point that the brain is a predictive engine. The brain tries to figure out the world by interpreting streams of electrical signals from the body. It combines the signals it receives with previous expectations/beliefs about the world to form its best guess as to what caused those signals. He gives examples of how the brain’s ‘best guess’ can go wrong. One example stuck out, the rubber hand illusion. In this experiment, the subjects real hand is hidden, and instead a fake rubber hand is placed within eyeshot. After a while touching the rubber hand is perceived by the subject as touch on the real hand. So much so that when someone suddenly stabs the rubber hand, the subject violently withdraws his hand in pain. Even our perception of what our bodies is is a kind of best guess or controlled hallucination!
Therefore, instead of perception depending on sensory information coming from the world, it depends as much or more on perceptual predictions flowing in the opposite direction. He emphasizes that, “We don’t just passively perceive the world, we actively generate it. The world we experience comes as much if not more from the inside out as from the outside in.” If we are depressed, anxious, regretful, self-pitying, or pessimistic, we are projecting negativity and therefore manifesting it in our body as a greater perception of pain.
How else does this information about our nervous system apply to chronic pain patients? Well, I see it every day of practice. A patient’s expectations affect their perception. If someone has told them that their MRI shows a defect, their mind incorrectly amplifies this into feeling that they are damaged. They then will act and feel debilitated even though there is nothing truly wrong. Once I can show them that these MRI findings are not a sign of disease, and that if they were my family member I would not operate on them, then their entire outlook changes. They are able to partake in appropriate rehabilitation and improve their function. The take home lesson is that YOU actively generate your reality, so when you incorrectly convince yourself that you are damaged, you will act and be damaged. Even if there is something wrong, you can do much better expecting that your body can heal itself with the right rehabilitation. In our clinics we give examples of patients who have healed with even worse MRI findings, setting up the expectation that each patient can obtain the same result.