PERCEPTION - GIBSONS BOTTON-UP THEORY

ACCORDING TO BOTTON-UP THEORY, HOW DO WE ANALYSE OUR VISUAL WORLD?     

WHAT DOES THE BOTTON-UP THEORY ASSUME?

WHAT IS BOTTOM-UP THEORY SOMETIMES REFERRED AS? WHY?

WHAT ARE THE CENTRAL ELEMENTS OF GIBSON BOTTOM-UP THEORY?

WHAT IS THE OPTIC ARRAY?

WHAT IS INVARIANT INFORMATION?

WE WORK UPWARDS IN OUR ANALYSE OF THE VISUAL WORLD FROM THE BASIC SENSORY INPUT AT THE BOTTOM LEVEL TO THE HIGHER MORE COGNITIVE LEVEL OF THE BRAIN

WE USE STORED KNOWLEDGE OR PAST EXPERIENCES AS THEIR IS ENOUGH INFORMATION CONTAINED IN THE SENSORY INPUTS TO KAE SENSE OF THE VIUSAL WORLD

DATA DRIVEN THEORY - SENSORY INPUTS ARRIVING AT THE RECEPTORS DRIVES THE PERCEPTUAL PROCESS

THE OPTIC ARRAY; THE IMPORTANCE OF MOVEMENT; INVARIANT INFORMATION (TEXTURE GRADIENT, OPTIC FLOW PATTERN, HORIZON RATION); DIRECT PERCEPTION

STRUCTURE OF LIGHT IN THE ENVIRONMENT - STARTING POINT FOR PERCEPTUAL PROCESS

EXTRACTED BY THE PERCEPTUAL SYSTEM AND USED TO GAUGE DEPTH, DISTANCE AND ORIENTATION OF OBJECTS (TEXTURE GRADIENT; OPTIC FLOW PATTERN; HORIZON RATIO)

EXPLAIN TEXTURE GRADIENT...

EXPLAIN THE OPTIC FLOW PATTERN...

EXPLAIN HORIZON RATIO...

WHAT IS DIRECT PERCEPTION?

WHAT DOES GIBSON MEAN BY AFFORDANCES?

EXPLAINS HOW WE SEE TEXTURE IN THE ENVIRONMENT AT DIFFERENT ANGLES AND DISTANCES - INDIVIDUAL ELEMENTS OF THE TEXTURE APPEARS CLOSER TOGETHER AS DISTANCE INCREASES

CREATED AS ELEMNTS IN THE ENVIRONMENT PASS ROUND A MOVING OBSERVER - GIBSON THOUGHT THE FLOW OF THE WHOLE VISUAL FIELD WAS MORE IMPORTANT THAN THE RELATIVE MOVEMENTS OF ISOLATED OBJECTS

EXTENT OF AN OBJECT THAT IS ABOVE THE HORIZON DIVIDED BY EXTENT OF OBJECT BELOW THE HORIZON

INFORMATION THAT IS AVAILABLE IN THE OPTIC ARRAY IS COMBINED WITH INFORMATION THAT FEEDS BACK FORM OUR PHYSICAL SURROUNDINGS

ALL OBJECTS OFFER US AN OPPORTUNITY TO MAKE USE OF THEM; CALLED AFFORDANCES AND WE PICK UP THESE MEANINGS DIRECTLY FROM THE ENVIRONMENT

WHAT DID GIBSON HIGHLIGHT?

HOW DOES GIBSONS THEORY FIT IN WITH EXISTING KNOWLEDGE OF PERCEPTION?

HOW IS GIBSONS THEORY REDUCTIONIST?

WHAT HAS DISPUTED GIBOSNS IDEA OF AFFORDANCES?

IMPORTANCE OF MOVEMENT AND THE NEED TO STUDY PERCEPTION IN THE NATURAL ENVIRONMENT

PERCEPTION IS KNOWN TO BE VERY FAST AND GENERALLY ACCURATE PROCESS

NOT CONCERNED WITH EXPLAINING PERCEPTION IN PHYSIOLOGICAL TERMS - YET REASEARCH HAS PROVIDED EVIDENCE OF NEURONS IN VISUAL CORTEX WHICH COULD BE RESPNSIBLE FOR SOME OF THE PERCEPTUAL PROCESSES GIBSON DESCROBED, E.G. NEURONS HAVE BEEN IDENTIFIED WHICH COULD UNDERPIN THE PERCEPTION OF OPTIC FLOW PATTERNS

KNOWLEDGE OF OBJECTS IS LEARNED RATHER THAN AFFORDED - AFFORDANCES CAN ONLY PROVIDE ADEQUATE EXPLANATION FOR LOWER ANIMAL FORMS

HOW DOES VIUSL ILLUSIONS DISPUTE GIBSONS THEORY?

HOW HAS GIBSON ARGUED THE ABOVE POINT?

PROVIDE ANOTHER EXPLANATION AS TO WHY GIBSONS THEORY ID REDUCTIONIST...

IF PERCEPTION IS A DIRECT PROCESS THAT GIBSON DESCRIBES VISUAL ILLUSIONS SHOULD NOT OCCUR YET PROPLE ARE SUSCEPTIBLE

GIBSON POINTED OUT THE ARTIFICIAL CONDITIONS IN WHICH EXPERIMENTS USING VISUAL ILLUSIONS WERE CARRIED OUT - YET SOME ILLUSIONS AFFECT US IN EVERYDAY LIFE

EMPHAISES DIRECT NATURE OF PERCEPTION AND DOESN'T CONSIDER THE ROLE OF EXPERIENCE AND STORED KNOWLEDGE, THERFORE IT IS MORE REDUCTIONIST THAN GREGORY'S CONSTRUCTIVIST APPROACH WHICH PROVIDES A MORE COMPRHENSIVE EXPLANANTION OF PERCEPTION THAN GIBSONS MORE LIMITED APPROACH