by Tom
Lately, while out cycling, I have been noticing how my brain makes sense of the visual information it is receiving.
The British neuroscientist Anil Seth has said, ‘We don’t just passively perceive the world; we actively generate it.’ And he explains the process in the following terms:
… the brain is continuously generating predictions about the causes of sensory signals … and sensory signals themselves serve as prediction errors, reporting a difference between what the brain expects and what it gets, so that the predictions can be continuously updated. Perception isn’t a process of reading out sensory signals … It’s always an active construction …I call controlled hallucination … the mind doesn’t make up reality. … it’s the way in which these things appear in our conscious experience that is always a construction.
So, the reality of the world [and the self, he argues elsewhere] is essentially a controlled hallucination based on the brain’s ‘informed guesswork predictions of how to make sense of the electronic impulses it is receiving’.
I often ride my bike on a track that, in part, follows a paddock with a fence made of several wire strands connected to wooden posts. One bright, sunny morning, I was surprised to see that the wires had disappeared, which of course meant that the cattle grazing beyond it could roam freely, posing a danger to themselves and the cyclists, joggers and walkers on the track. Then, as the track turned slightly, much to my relief I saw that indeed the wire strands were still intact. Something about the angle of the sun had rendered them briefly invisible.
What seemed to have been occurring was an illustration of Seth’s theory. For a short while data from my eyes did not register the wire strands, so the best my poor brain could do was to conclude they weren’t there. When the angle of sun changed, my brain quickly registered the existence of the wire and so changed reality to accommodate this new bit of information, though of course, the wire had always been there.
Brain watching now has become a kind of game when I’m out on my bike as I gaze ahead and watch a person turn into a signpost, or a wombat by the side of the track turn into a boulder, as my befuddled brain creates changing realities on the basis of the visual clues it is receiving.
This explanation of the construction of reality dovetails nicely with the Zen approach to what is real. Reality is an emptiness that lies behind the delusions of our sense perceptions and mental constructs. This is also true of the stories we weave about our selves and about others. Our brains continuously try to make sense of our encounters with other people and with the thoughts and emotions that surface within our own very active minds. We tend to accept these constructs as real, when they are in fact what Seth would call hallucinations. The ‘Heart Sutra’ reminds us that ‘feelings, perceptions, impulses and the rest of consciousness’ are only emptiness. And as our ‘Practice Principles’ state, generally we are imprisoned in a ‘self-centred dream’.
So our practice becomes to see things just as they are without our self-generated embellishments. ‘Just this!’