Question

Cognitive Psychology

*Discuss the visual system, visual information processing, and speech cognition

*Define perception and the visual system’s operation

*Discuss the theories of visual object recognition, including feature analysis theory and recognition-by-components theory

*Define speech perception, and provide an explanation of speech perception theories, including special mechanism approach, phonetic module, and categorical perception

Answer 1

Visual cognition is a branch of phychology which deals by combining visual data with prior knowledge to construct high level representations and unconsious decisions are made about scene content.Visual system is a sensory system which is developed to perceive the environment through light , which uses light to form images of surrounding, so in the rectina there is conversion of light energy into neutral activity.Visual information processing is the ability to interprect what is seen, which means being quickly and accurately able to process and analyse what is seen and store in visual memory for later recall.

Perception is the organization, identification, interpretation of sensory information inorder to understand the presented information or the environment,visual perseption is something that happens after the picture reaches eye, the image forms a pattern of activity on the array of receptors on the eye and the image in a detailed pattern is analysed by visual centers of brain and then reveals what was there.As the image reaches rectina form electrical signals and sent via otiv nerve to parts of brain, which processes,the image and allows us to see.Visual system consist of sensory organ as eye which is the part od CNS which gives the organism the visual detail as sight, as well as enabling the formation of several non image photo resposes functions.

Theories are 'recognition by components' which is given by Irving Biederman in 1987 deals with recognition of complex shapes, the objects are arranged in Geons he listed that 36 geons form 3D objects.

Support for recognition by components theory fMRI and neuronal responses to geons , younger children may perceieve undifferentiated objects but older children represent

Support for feature analysis theory developed by Hubel and Wiesel in 1960 -1980

Modification to recognition by component theory view cebtered approch ; we store a small no: of views in 3D approch

Bottom up processing theory, top down processing theory.

Speech perception is the process by which the sounds of language is heard,interpected and understood.

Theories includes; Motor theory perception involves process related to production of speech,

-Motor theory by LIBERMAN in 1967 the lisener specifically perceieves speakers phonetic gestures while they are speaking.

Analysis by synthesis model by STEVENS AND HALLE in 1967  

- Direct perception, perception recovers the sound producing objects directly.

Fowlers direct realist approch by carol fowler in 1986listeners perceive gestures not by means of specialized decoder but because information in the accoustic signal specifiesgestures that form it.

- Stage theories perception involves sequence of tranforms from sound to objecta for instance, TRACE AND LAFS.

Phonetic module is a special neural mechanism that handles all the aspects of speech perceptions,Categorical perception is when a person hears a sound halfway between the letters, but they either hear one of the letters clear cut, it is invoved in the process of perseptual diffentiation.