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Is my eye “digital”? My eye has a finite number of sensors, in four types, gray scale, red, blue and green sensitive, and these are sensitive to individual photons. They are arranged in groups to collect low light (grain) and the nerve cell has a response of a volley of pulses whose frequency depends on the degree of stimulation. The response is logarithmic and frequency modulated, spatially mapped in the same innervation pattern as the skin. A persons bare back can detect shapes drawn by a finger, like the eye.
The number of elements in the eye exceeds the number of conducting nerve fibers in the optic nerve and so a spatial compression process is used to allow more information to be passed. There are only about a million individual nerve fibers in each eye but these get expanded to about ten million in the brain. The eye scans around to build up the stable image in the brain which is probably about 50 million pixels. However this received image is not seen here at the visual cortex and is processed by the nerve pathways in a series of parallel processors until in reaches the frontal lobe where the final integration takes place and where the response is worked out. All this takes place in about 2 tenths of a second this is the simplest reflex action that takes only three synapses. Higher level responses take several seconds and pass through hundreds of parallel processors each with only one synapse. There are very high level responses that can take hours or years of processing. These pass through thousands of parallel processes of one synapse and are iterative in nature.
So seeing is a highly complex process and commentary on pictures is a slow and very high level process.
So is it digital?
-----Original Message-----
In a message dated 4/11/05 7:17:58 AM Central Daylight Time,
cameratraveler@xxxxxxxxxxxxx writes: "Lit with piercing glances into the life of
things";
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