Perception

Looking for the eraser under the desk (see top page) can be imagined to happen like this: "Eyes of ours, look at this place under the desk and see the eraser (it must be there)." And eyes of ours respond: "We are looking at this place under the desk, but we do not see the eraser." -- A bit less sure: "Eyes of ours, look somewhere under the desk and see something that might be the eraser (it should be somewhere there)." And eyes of ours respond: "We are looking under the desk and we see something that might be the eraser." -- YES, YES: "eyes of ours, look at this another place under the desk and see the eraser (it must be there)." And eyes of ours respond: "We are looking at this place under the desk and we see the eraser."

Decades were wasted in pattern (image, speech) recognition based on something like this: "eyes of ours, look and tell me what you see." And eyes of ours do not respond thinking: "There is a myriad of things to see. What are we supposed to see? This spec of dust? Nay... Must be something else. But what?"

Building an image of the world that surrounds us from scratch based on raw sensory input is a long and tedious process. It is hard to imagine it happening every fraction of a second of our life. Such a model of a passive reception, transmission and processing of an enormous quantity of stimuli in our brain is refuted not only by numerous neurological findings, but also by findings in psychology, anthropology, biology... A model of active perception seems much more appropriate and better supported.

Attempts by psychologists to explain visual illusions led them to a concept in which: "The senses do not give us a picture of the world directly; rather they provide evidence for the checking of hypotheses about what lies before us." Richard L. Gregory

A model of active perception is based on constantly refreshed "description of the world and ourselves within it". The assumption is that at any point in time we construct that description within ourselves seeking only a confirmation of it through our senses. As large discrepancies are kept at a minimum, there is no cause for alarm. Large or sudden discrepancies on the other hand result in a need for major readjustments. And this takes a measurable time during which our perception is distorted. (As we listen to somebody speaking, for example - we silently speak together with the speaker. We might even hear what was not said without noticing a discrepancy, but if we notice this - our hearing falls into disarray, and we either stop the speaker, or find a new starting point and continue to silently speak with the speaker.)

Visual Recognition Begins with Categorization

Each of us has a unique, self-referring "description of the world and ourselves within it" rooted in our genetic material and crowned by our own cosmogonies and cosmologies based on our "cultural imprints". Through our genetic makeup, language and culture, it is inherited, lived through and passed onto posterity. This immense knowledge accumulated since the emergence of life (through our genetic makeup) with accelerated accumulation by emergence of our cultures - is continuously faced, tested and modified with our "subjective" experience of the richness of the world of our transient now.