uasetr.blogg.se - Visual perception definition psychology

Our perceptions of the world are hypotheses based on past experiences and stored information.

Richard Gregory proposed that perception involves a lot of hypothesis testing to make sense of the information presented to the sense organs.

We actively construct our perception of reality.

Therefore, the brain has to guess what a person sees based on past experiences.

A lot of information reaches the eye, but much is lost by the time it reaches the brain (Gregory estimates about 90% is lost).

In this way, we are actively constructing our perception of reality based on our environment and stored information. Helmholtz called it the ‘likelihood principle’.įor Gregory, perception is a hypothesis which is based on prior knowledge. Stimulus information from our environment is frequently ambiguous, so to interpret it, we require higher cognitive information either from past experiences or stored knowledge in order to make inferences about what we perceive. Psychologist Richard Gregory (1970) argued that perception is a constructive process that relies on top-down processing. Gregory (1970) and Top-Down Processing Theory This is because the meaning of the surrounding words provides a context to aid understanding. For example, understanding difficult handwriting is easier when reading complete sentences than reading single and isolated words.

Top-down processing refers to the use of contextual information in pattern recognition. Processing is carried out in one direction from the retina to the visual cortex, with each successive stage in the visual pathway carrying out an ever more complex analysis of the input. Psychologists distinguish between two types of processes in perception: bottom-up processing and top-down processing.īottom-up processing is also known as data-driven processing because perception begins with the stimulus itself. This controversy is discussed with respect to Gibson (1966), who has proposed a direct theory of perception which is a “bottom-up” theory, and Gregory (1970), who has proposed a constructivist (indirect) theory of perception which is a “top-down” theory. Some argue that perceptual processes are not direct but depend on the perceiver’s expectations and previous knowledge as well as the information available in the stimulus itself. Sensory inputs are somehow converted into perceptions of desks and computers, flowers and buildings, cars and planes, into sights, sounds, smells, tastes, and touch experiences.Ī major theoretical issue on which psychologists are divided is the extent to which perception relies directly on the information present in the environment. Each sense organ is part of a sensory system that receives sensory inputs and transmits sensory information to the brain.Ī particular problem for psychologists is explaining how the physical energy received by sense organs forms the basis of perceptual experience. To receive information from the environment, we are equipped with sense organs, e.g., the eye, ear, and nose. Evaluation of Gibson’s (1966) Direct Theory of Perception.Critical Evaluation of Gregory’s Theory.

Gregory (1970) and Top-Down Processing Theory.The ultimate goal of the interventions is to facilitate children to engage in meaning, age-appropriate occupations. Therapists can apply environmental adaptations within the visual input stage and employ techniques of remediation, strategies and environmental adaptations within the visual processing and output stages. Visual processing involves input, processing, and output, followed by feedback, and this pattern is used when applying this frame of reference in intervention planning. In evaluation, therapist asks and observes how visual perceptual difficulties limit occupational performance and participation, and identifies underlying influencing visual perceptual factors in the process. Stimulation is necessary for children to acquire this skill. It involves a receptive component and a cognitive component. Visual perception processing is learned and developed from experience and practice. This frame of reference assumed that learning does not necessarily follow this hierarchy, which means that deficit in one area does not predict deficit in another area. The next levels are sequential attention, scanning, pattern recognition, visual memory, visuocogntion, and eventually adaptation through vision. Visual Perceptual skill development is viewed to be developed from a hierarchy, starting from oculomotor control, visual fields, visual acuity. It uses theories from cognition, developmental psychology, education, and Warren’s developmental hierarchy of visual perceptual skills. This frame of reference adapts a top-down approach to identify visual perceptual factors that limit an individual’s daily participation, and adaptive and compensation approaches are used to facilitate engagement in meaningful occupation.