Theories of perception

Perception is a combination of both the physiological operationes involved within the senses and the way in which the brain integrates and interprets the sensory discipline that it takes in. The two main explanations of perception prioritise the role of one or other of these different aspects. The bottom-up theory emphasises the importance of stimulus features in perception. The optical information that reaches the eye is thought to contain sufficient unambiguous information about an object for ffective perception to take place with little further processing.Gibson suggested that vindicated reaching the eye does so in an optic array. This provides information about such things as distance, movement and meaning. Interpretation is achieved through analysis of the information in the optic array by means of various cues such as texture gradient and horizon ratio. The former refers to the fact that the texture of an object becomes little clear the further it is away. By picking up thi s information an observer is able to perceive some aspects of depth. Gibson rejected the view that we erceive a meaningful purlieu because of the involvement of stored knowledge and experience.He claimed that the meaning of a stimulus is determined by the objects affordance, ie the physical structure of an object gives clues as to what its potential use. Eysenck and Keane (1990) suggest that the pattern of affordances is central to Gibsons theory as otherwise he would be forced to admit that the meaning of objects is something we store in long-term memory. Gibsons theory has provided a hefty explanation of the generally fast and accurate perception of the environment ut it does struggle to explain why we do sometimes make mistakes, as with illusions.An ersatz explanation of perception is that of the top-down approach suggested by Gregory. This sees the eventual product of perception being constructed, that is, built up from a combination of stimulus information, expectations and hypotheses. The process involves making sense of all the various bits of information provided by the senses. A key aspect of this view of perception is that because of the role of the hypotheses and expectation, perception will be frequently prone to error.