Wednesday, 25 June 2008

Persistence of Vision

The part of the brain that deals with vision only gets 10-20% of its information from the eyes; the remainder comes from our memory banks. Is it possible that we do not see—we merely recognise?
It is almost as though the new information is being weaved into what we already know of the world, with all our idiosyncrasies and prejudices. It may explain how two people, upon witnessing the same event, can report differently. As the Talmud says, "We do not see the world as it is; we see the world as we are."
In film, the term 'ellipsis' refers to a gap in the narrative where the viewer fill in the blanks: a man is walking down a hallway; the next shot shows him closing the door from the outside. We fill in the gap—the ellipsis—with our own scripted memory, so familiar to us, called 'leaving the house'.
Magicians also depend on this ability, and delight us by confounding our well-worn expectations.

It is not only vision that is muddied by memory. Patients who have lost hands can complain that a ring on that hand is too tight. It is hard to know how far back these echoes of memory go: a woman born without arms reported feeling herself gesturing when she spoke, with limbs only her ancestors had.

The Enlightenment freed the Western world from the magical thinking of religion slopping over into everyday life, but in its enthusiasm for systems neglected to abandon the religious idea that we are cut from whole cloth. This legacy, a mechanistic model for the world, and for our bodies, leaves us with the idea that we are almost automatons, with clear and distinct inputs and sharply-defined seperations. Evolutionary biology shows this to be a noble myth. We are in fact a jerry-rigged collection of odd parts, bearing the junk-DNA scars of millions of years of false starts and scraping by. Our faculties are less like computers and more like jungle eco-systems; they work organically, evolving and devolving by luck and the slightest of advantages.
When our systems go haywire, it helps to remember that we are not pristine and finely-tuned products of a single mind or purpose. We are grizzled, ramshackle survival machines.

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