Perception
Perception (from the Latin perceptio, percipio) is the organization, identification and interpretation of sensory information in order to represent and understand the environment. All perception involves signals in the nervous system, which in turn result from physical stimulation of the sense organs. For example, vision involves light striking the retinas of the eyes, smell is mediated by odor molecules and hearing involves pressure waves. Perception is not the passive receipt of these signals, but can be shaped by learning, memory and expectation. Perception involves these "top-down" effects as well as the "bottom-up" process of processing sensory input. The "bottom-up" processing is basically low-level information that's used to build up higher-level information (i.e. - shapes for object recognition). The "top-down" processing refers to a person's concept and expectations (knowledge) that influence perception. Perception depends on complex functions of the nervous system, but subjectively seems mostly effortless because this processing happens outside conscious awareness.
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Famous quotes containing the word perception:
“Action from principle, the perception and the performance of right, changes things and relations; it is essentially revolutionary, and does not consist wholly with anything which was. It not only divides States and churches, it divides families; ay, it divides the individual, separating the diabolical in him from the divine.”
—Henry David Thoreau (18171862)
“No one has ever seen a Republican mass meeting that was devoid of the perception of the ludicrous.”
—Mark Twain [Samuel Langhorne Clemens] (18351910)
“Men are not philosophers, but are rather very foolish children, who, by reason of their partiality, see everything in the most absurd manner, and are the victims at all times of the nearest object. There is even no philosopher who is a philosopher at all times. Our experience, our perception is conditioned by the need to acquire in parts and in succession, that is, with every truth a certain falsehood.”
—Ralph Waldo Emerson (18031882)