This is the last post in my series on diagrams. This diagram shows how feedback mechanisms in the brain, in conjunction with the prefrontal cortex generate both our behaviour and our consciousness or sense of self.
I think consciousness, our sense of self, comes from some simple feedback mechanisms in our brains. It comes in two parts, how we feel about ourselves and how we think about ourselves. I think, evolutionarily speaking, it develops, particularly in predators and in social animals, as a side-effect of the organism making a mental map of the world which includes itself.
Now, while I have a background in neurophysiology and worked as a neuroscientist straight after university, I want to try to explain this idea in a straight forward way. So I made this diagram to show how I think this might work at a very basic level…
Following the diagram
Starting at the bottom (and sides) of the diagram and working upwards, we begin with 4 basic types of brain input:
① – Internal body sensations – sensory information which originates inside the body. This includes things like internal pain, gut sensations, bladder fullness, proprioception (awareness of the body’s position relative to itself), etc.
② – External sensory input – this includes all sensory information which the body collects from the world around us and includes things like sight, smell, touch, hearing and taste.
⑧ – Feedback of thoughts – Processing information is fed back into the brain.
⑨ – Feedback of feelings – Information from the limbic system (arousal and emotion) is fed back into the brain.
These inputs come into our brains ③ .
This pattern of information is brought together to make a mental map of ourselves and the world around us ⑤ .
Various possible responses to this situation are generated ⑥ . One of these is then chosen by the brain as the action the body will take.
At each stage what is happening is fed back to the cortex , so the brain becomes aware of new sensory information, updates the mental map, generates possible actions and guesses outcomes, chooses which action to take and acts. Then the cycle repeats.
There are some interesting ideas and predictions that come out of this theory:
- The sense of self is just another internal “object” in the mental map we create about the world. It feels like walking on shaky ground to think too deeply about this because really all we are is a figment of our own imagination, based on various cortical processing pathways.
- We can be wrong about our own selves. We can be unaware of things that we do. Just as our mental map can have errors, so can that part of the map which we call “I”. For instance, when I think hard, according to my son, I scowl. When this is happening though I feel perfectly happy. I love thinking hard and never thought I could have a scowl on my face when doing this but, after my son mentioned it, I checked it with a mirror and he was right! My map of myself was wrong.
- It is because we make our own mental map of ourselves and our environment that stories have such power for us. We can use the same processing to enjoy stories as we do to know about ourselves and our world.
- This model also predicts that our sense of self will become aware of something mentally after the processing is already done. Our self is part of an “after action report” if you like. So we feel like we make decisions but our brains make them and then it feels like it was us.
How I made the diagram
I began by making the four main assets I needed in my diagram – the picture of a person, the picture of an environment, the picture of a brain and the picture of a mental map.
I made the person and the brain assets by doing ink drawings of each, scanning them in, cleaning them and colouring them. Here are the original ink drawings.
I made the environment image by re-purposing an image from a previous diagram I made about the self…
… and did a similar thing for the mental map picture which I put inside a comic style thought cloud to show it was a thought-based picture…
Once I had these made I just arranged them and drew on a lot of notes and arrows. It was fiddly but fairly easy to do. The hardest part of this was working out my theory of how the brain works!
So here’s the final diagram I came up with…
(PS: This post was written in half term but I haven’t been able to do my usual checking and polishing. I am currently in isolation due to a cough and a temperature. I think I’ve probably got laryngitis which is causing the cough and temperature rather than coronavirus but I’ve been advised by my GP to isolate anyway so that’s what I’m doing. Unfortunately I’ve also got a splitting headache so I apologise if there are any mistakes in this post as I haven’t checked it.)