July 6, 2019

WE ARE ALL DESIGNIST:

Now you see it: Our brains predict the outcomes of our actions, shaping reality into what we expect. That's why we see what we believe (Daniel Yon, 7/06/19, Aeon)

One challenge that our brains face in monitoring our actions is the inherently ambiguous information they receive. We experience the world outside our heads through the veil of our sensory systems: the peripheral organs and nervous tissues that pick up and process different physical signals, such as light that hits the eyes or pressure on the skin. Though these circuits are remarkably complex, the sensory wetware of our brain possesses the weaknesses common to many biological systems: the wiring is not perfect, transmission is leaky, and the system is plagued by noise - much like how the crackle of a poorly tuned radio masks the real transmission.

But noise is not the only obstacle. Even if these circuits transmitted with perfect fidelity, our perceptual experience would still be incomplete. This is because the veil of our sensory apparatus picks up only the 'shadows' of objects in the outside world. To illustrate this, think about how our visual system works. When we look out on the world around us, we sample spatial patterns of light that bounce off different objects and land on the flat surface of the eye. This two-dimensional map of the world is preserved throughout the earliest parts of the visual brain, and forms the basis of what we see. But while this process is impressive, it leaves observers with the challenge of reconstructing the real three-dimensional world from the two-dimensional shadow that has been cast on its sensory surface.

Thinking about our own experience, it seems like this challenge isn't too hard to solve. Most of us see the world in 3D. For example, when you look at your own hand, a particular 2D sensory shadow is cast on your eyes, and your brain successfully constructs a 3D image of a hand-shaped block of skin, flesh and bone. However, reconstructing a 3D object from a 2D shadow is what engineers call an 'ill-posed problem' - basically impossible to solve from the sampled data alone. This is because infinitely many different objects all cast the same shadow as the real hand. How does your brain pick out the right interpretation from all the possible contenders?

All "progress" in science thrusts us farther back on the reality that all we "know" we know by faith. Post-modernism=Pre-modernism.

Posted by at July 6, 2019 10:13 AM

  

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