User:Jasonaperez7/sandbox

The receptive field is the specific part of the world to which a receptor organ and receptor cells respond. For instance, the part of the world an eye can see, is its receptive field; the light that each rod or cone can see, is its receptive field.^[41] Receptive fields have been identified for the visual system, auditory system and somatosensory system, so far. Research attention is currently focused not only on external perception processes, but also to "Interoception", considered as the process of receiving, accessing and appraising internal bodily signals. Maintaining desired physiological states is critical for an organism’s well being and survival. Interoception is an iterative process, requiring the interplay between perception of body states and awareness of these states to generate proper self-regulation. Afferent sensory signals continuously interact with higher order cognitive representations of goals, history, and environment, shaping emotional experience and motivating regulatory behavior.^[42]

Features

Constancy

Perceptual constancy is the ability of perceptual systems to recognize the same object from widely varying sensory inputs.^{[43]: 118–120 [44]} For example, individual people can be recognized from views, such as frontal and profile, which form very different shapes on the retina. A coin looked at face-on makes a circular image on the retina, but when held at angle it makes an elliptical image.^[17] In normal perception these are recognized as a single three-dimensional object. Without this correction process, an animal approaching from the distance would appear to gain in size.^[45][46] One kind of perceptual constancy is color constancy: for example, a white piece of paper can be recognized as such under different colors and intensities of light.^[46] Another example is roughness constancy: when a hand is drawn quickly across a surface, the touch nerves are stimulated more intensely. The brain compensates for this, so the speed of contact does not affect the perceived roughness.^[46] Other constancies include melody, odor, brightness and words.^[47] These constancies are not always total, but the variation in the percept is much less than the variation in the physical stimulus.^[46] The perceptual systems of the brain achieve perceptual constancy in a variety of ways, each specialized for the kind of information being processed^[48], with phonemic restoration as a notable example from hearing.

Grouping

The principles of grouping (or Gestalt laws of grouping) are a set of principles in

A common finding across many different kinds of perception is that the perceived qualities of an object can be affected by the qualities of context. If one object is extreme on some dimension, then neighboring objects are perceived as further away from that extreme. "Simultaneous contrast effect" is the term used when stimuli are presented at the same time, whereas "successive contrast" applies when stimuli are presented one after another.^[54]

The contrast effect was noted by the 17th Century philosopher John Locke, who observed that lukewarm water can feel hot or cold, depending on whether the hand touching it was previously in hot or cold water.^[55] In the early 20th Century, Wilhelm Wundt identified contrast as a fundamental principle of perception, and since then the effect has been confirmed in many different areas.^[55] These effects shape not only visual qualities like color and brightness, but other kinds of perception, including how heavy an object feels.^[56] One experiment found that thinking of the name "Hitler" led to subjects rating a person as more hostile.^[57] Whether a piece of music is perceived as good or bad can depend on whether the music heard before it was pleasant or unpleasant.^[58] For the effect to work, the objects being compared need to be similar to each other: a television reporter can seem smaller when interviewing a tall basketball player, but not when standing next to a tall building.^[56] In the brain, brightness contrast exerts effects on both neuronal firing rates and neuronal synchrony.^[59]

Theories

Perception as direct perception

An ecological understanding of perception derived from Gibson's early work is that of "perception-in-action", the notion that perception is a requisite property of animate action; that without perception, action would be unguided, and without action, perception would serve no purpose. Animate actions require both perception and motion, and perception and movement can be described as "two sides of the same coin, the coin is action". Gibson works from the assumption that singular entities, which he calls "invariants", already exist in the real world and that all that the perception process does is to home in upon them. A view known as constructivism (held by such philosophers as Ernst von Glasersfeld) regards the continual adjustment of perception and action to the external input as precisely what constitutes the "entity", which is therefore far from being invariant.^[64]

Glasersfeld considers an "invariant" as a target to be homed in upon, and a pragmatic necessity to allow an initial measure of understanding to be established prior to the updating that a statement aims to achieve. The invariant does not and need not represent an actuality, and Glasersfeld describes it as extremely unlikely that what is desired or

Many philosophers, such as Jerry Fodor, write that the purpose of perception is knowledge, but evolutionary psychologists hold that its primary purpose is to guide action.[66] For example, they say, depth perception seems to have evolved not to help us know the distances to other objects but rather to help us move around in space.^[66] Evolutionary psychologists say that animals from fiddler crabs to humans use eyesight for collision avoidance, suggesting that vision is basically for directing action, not providing knowledge.^[66]

Building and maintaining sense organs is metabolically expensive, so these organs evolve only when they improve an organism's fitness.^[66] More than half the brain is devoted to processing sensory information, and the brain itself consumes roughly one-fourth of one's metabolic resources, so the senses must provide exceptional benefits to fitness.^[66] Perception accurately mirrors the world; animals get useful, accurate information through their senses.^[66]

Scientists who study perception and sensation have long understood the human senses as adaptations.^[66] Depth perception consists of processing over half a dozen visual cues, each of which is based on a regularity of the physical world.^[66] Vision evolved to respond to the narrow range of electromagnetic energy that is plentiful and that does not pass through objects.^[66] Sound waves provide useful information about the sources of and distances to objects, with larger animals making and hearing lower-frequency sounds and smaller animals making and hearing higher-frequency sounds.^[66] Taste and smell respond to chemicals in the environment that were significant for fitness in the environment of evolutionary adaptedness.^[66] The sense of touch is actually many senses, including pressure, heat, cold, tickle, and pain.^[66] Pain, while unpleasant, is adaptive.^[66] An important adaptation for senses is range shifting, by which the organism becomes temporarily more or less sensitive to sensation.^[66] For example, one's eyes automatically adjust to dim or bright ambient light.^[66] Sensory abilities of different organisms often coevolve, as is the case with the hearing of echolocating bats and that of the moths that have evolved to respond to the sounds that the bats make.^[66]

Evolutionary psychologists claim that perception demonstrates the principle of modularity, with specialized mechanisms handling particular perception tasks.^[66] For example, people with damage to a particular part of the brain suffer from the specific defect of not being able to recognize faces (prospagnosia).^[66] EP suggests that this indicates a so-called face-reading module.^[66]

Closed-loop perception

Here perception is proposed to be a dynamic motor-sensory closed-loop process in which information flows through the environment and the brain in continuous loops^{[67][68][69][70][71]}, converging towards steady-state percept.

Theories of perception

• Empirical theories of perception
• Enactivism
• Anne Treisman's feature integration theory
• Interactive activation and competition
• Irving Biederman's recognition by components theory

Effect of experience