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.

Since the rise of experimental psychology in the late 19th Century, psychology's understanding of perception has progressed by combining a variety of techniques. Psychophysics measures the effect on perception of varying the physical qualities of the input. Sensory neuroscience studies the brain mechanisms underlying perception. Perceptual systems can also be studied computationally, in terms of the information they process. Perceptual issues in philosophy include the extent to which sensory qualities such as sounds, smells or colors exist in objective reality rather than the mind of the perceiver.

Although the senses were traditionally viewed as passive receptors, the study of illusions and ambiguous images has demonstrated that the brain's perceptual systems actively and pre-consciously attempt to make sense of their input. There is still active debate about the extent to which perception is an active process of hypothesis testing, analogous to science, or whether realistic sensory information is rich enough to make this process unnecessary.

The perceptual systems of the brain enable individuals to see the world around them as stable, even though the sensory information may be incomplete and rapidly varying. Human and animal brains are structured in a modular way, with different areas processing different kinds of sensory information. Some of these modules take the form of sensory maps, mapping some aspect of the world across part of the brain's surface. These different modules are interconnected and influence each other. For instance, the taste is strongly influenced by its odor.

Read more about Perception:  Process and Terminology, Perception and Reality, Effect of Experience, Effect of Motivation and Expectation, Physiology

Other articles related to "perception":

Legacy Of The Battle Of The Alamo - Perception
... In Mexico, perceptions of the battle have often mirrored those of Santa Anna ... Initially, reports of the Mexican victory concentrated on glorifying Santa Anna, especially among newspapers that supported the centralist cause ...
Common Coding Theory - Related Approaches
... While most traditional approaches tend to stress the relative independence of perception and action, some theories have argued for closer links ... Motor theories of speech and action perception have made a case for motor contributions to perception ... Close non-representational connections between perception and action have also been claimed by ecological approaches ...
Leibniz's Gap
... It must be confessed, moreover, that perception, and that which depends on it, are inexplicable by mechanical causes, that is, by figures and ... it, pieces which push one against another, but never anything by which to explain a perception ...
Perception - Types - Of The Social World
... Social perception is the part of perception that allows people to understand the individuals and groups of their social world, and thus an element of social cognition ...
Cretien Van Campen - Fields of Interest - Perception
... He showed that the apparent rise of Gestalt psychology in perception research in the 1910s had its roots in late 19th century art history in Germany ... between artistic and scientific experiments with visual perception since the Renaissance ... After finishing his thesis, his interests moved to the perception of music ...

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.
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    Only by being guilty of Folly does mortal man in many cases arrive at the perception of Sense. A thought which should forever free us from hasty imprecations upon our ever-recurring intervals of Folly; since though Folly be our teacher, Sense is the lesson she teaches; since, if Folly wholly depart from us, Further Sense will be her companion in the flight, and we will be left standing midway in wisdom.
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    The beginning of human knowledge is through the senses, and the fiction writer begins where human perception begins. He appeals through the senses, and you cannot appeal to the senses with abstractions.
    Flannery O’Connor (1925–1964)