PRELIMINARY FOR PHYSIOLOGY OF
PERCEPTION
ANIL MITRA PHD, COPYRIGHT © 2001, REFORMATTED June
2003
Document status: June 7, 2003
No action necessary
May be useful if I return to think about perception – especially the point that there is no ultimate benchmark for the quality and validity of perception
Related to Wittgenstein’s thought
CONTENTS
How can there be an experience of
seeing at all?
Does one see shapes as they are?
I am looking at a mountain. Do I
see the shape of the mountain as it is?
Simple questions – just the
mechanics of recognition
A camera picks up an image. A robot can translate an image into signals, process, compare, select and respond. But, does it see? And if the answer is yes – how is it able see i.e., how does it have an experience of seeing?
Here, I am looking at simpler issues that may be part of a solution to the question above
Of course I do not see every surface feature – every blade of grass, each stone. But that is not the question. There is an overall shape that makes a mountain a mountain. Do I see that shape as it is?
How do I know that what I see is anything like the shape of the mountain? To begin with I can compare the mountain with its image on a retina. Although one is much larger and three dimensional and the other is two dimensional, the shape is similar. But the question remains – how do I know that what I see for either shape is anything like the original?
But – how do I know that the mountain has a shape independently of its being experienced? Perhaps it does not. In that case, what can I say about “the shape of the mountain”?
I have an experience of shape – and of size. This experience of shape for the mountain permits me to negotiate it in various ways. Perception of shape gives me some valid clues as to the shape of the routes up the mountain. For smaller objects there is an agreement between visual and tactile data. And there is agreement between geometry and senses
I can have a valid experience of shape without there being any objective shape
Shape as I experience it is a form of intuition and the analysis is similar to the analysis of color in Journey in Being
Shape can be defined formally e.g. in mathematics and then related to [motivated by] the perception of shape
I am now walking by the shore of a lake and am noticing the features – the rocks, the surface texture or rocks, cracks, contours, stones, tufts of grass, a burnt stick – many details on many levels of scale. It is somewhat surprising – if I ask how I do it – that I effortlessly recognize so much detail. What is going on?
Two eyes. Nerve pathways. Visual cortex. Eyes come with muscles that adjust and coordinate. Brain combines signals from both eyes… and the individual ends up with an image. There is no geometric image in the brain. There may, of course, be some complex mapping
Part and whole
Shape
Quality: color, texture
Memory
Hardware: eyes, pathways … and brain
Processing – “software”
The software is not written on the brain from the outside. A computer has an external maker who interprets physical configurations as information. An individual is in part his or her own maker but part of that is not conscious; and there is no interpretation of configurations as information
How are the foregoing considerations significant?
It is the perception that made the question. The question did not make the perception