Nociception is subject to all the truths and flaws of any other input system.
Patients never have this view, since their pain has been described to them in terms of body parts and structures. However, the tissue is as important in pain as the eyeball is in what we see.
This past week’s viral internet subject is a great example of all that (Black ‘n’ Blue dress). Vision is simply our brain’s decision based on the information available to it, including, but not limited to, the light waves of objects. The eye itself is simply an information gathering tool, the optic nerves and radiations are conduction pathways for that information, and it is our occipital cortex, along with association areas, that determine what we “see.” (Please reference the unbelievably fascinating Cortical Blindness. Inversely, you ‘see’ in your dreams. No eyes needed.)
Our focal visual fields are quite small, and much of what we think we see is made up, filled in and inferred in our brain. Go ahead, concentrate on what you can ‘see’ clearly in your visual field… it’s just a small bit in the middle that we take in accurately. A wonderful example of this from Ash Donaldson is to ask “why do you have to scan the sky to see a small plane?” If we actually “saw” the whole sky, we could just look up and see. But we don’t see, our brain fills in what we expect to be there: blue space.
Pain works the same way. It is a result of the information we can gather from many input sources. We paint the picture of what is occurring, and sometimes our brain fills in the rest.
So, a truth comes forth here: Our lives and existence occur inside us. Life is derived from the input we gather from our body’s “feelers” out into the world. But there is no world without our perception of it.
We do not see our desk in front of us. Light from the desk comes in through our lenses, travels via electrical impulses along the optic radiations, and we actually ‘see’ the desk inside ourselves. Same goes with touch, hearing… and nociception. Our external world occurs within.
Yes, cue the Matrix. Yes, cue questions of existence and consciousness.
These concepts are difficult to apply to the patient who is feeling the pain in that certain spot and is living it at the moment. From my experience 97% of people don’t want to hear anything about their pain, other than what I can do to get rid of it. So we will put images in front of the eyeball. We will bias the A-Betas vs the C fibres. We will try to give the right input to the body.
Of course we don’t ignore the body tissues, because they lend a great deal of input to the picture. Their relative fullness, tension, position, velocities, etc. It is all relevant because we need to help people find the plane in the sky…
Thank you for reading this… in your own voice… in your head.
More on Visual Dominance.