How much do our senses tell us about the world? Well, we already know that there’s a lot they miss. Infra-red and ultraviolet light, ultrasonic waves, and a host of tastes and smells that our animals friends can detect, are imperceptible to us.
But even the things we can see, hear and feel can’t necessarily be trusted. As much as it may seem like it, our senses don’t give us an objective, unfiltered view of the world. What we perceive is simply our brain’s best guess of what’s going on around us based on past experience, our current emotional state, and plain old fashioned guesswork.
This is beautifully pointed out in this piece by Anil Seth on the nature of the self (emphasis mine).
The story emerging from a rich blend of philosophy, psychology, and neuroscience is that the self is not ‘that which does the perceiving’. Instead, the self is a perception too. Or rather, it is a collection of related perceptions. Experiences of the world, and of the self, are created by the brain following a common principle – a principle of ‘best guessing’, or what we might call ‘controlled hallucination’.
The bedrock idea is simple. Raw sensory signals are ambiguous and unlabelled. Although they reflect really-existing properties of the world, they do so only indirectly. The eyes are not transparent windows from a self out onto a world, nor are the ears, nor are any of our senses. The perceptual world we encounter – a world full of well-defined objects with various properties like shape and colour – is created by the brain through a process of inference, of under-the-hood neurally-implemented probabilistic guesswork. When I see a red coffee mug on the table in front of me, this is because ‘red coffee mug’ is the brain’s best guess of the hidden and ultimately unknowable causes of the corresponding sensory signals. When I experience the glow of a sunset, or the sharp taste of an adventurous cheese, that too is a perceptual best-guess. We never experience sensory signals ‘in-the-raw’. Every experience is an interpretation, a construction.