Perception Top Down or Bottom up?

Visual Perception Theory Each sense organ is part of a sensory system But how do we explain the process by which the physical energy received by sense organs forms the basis of perceptual experience?

Gibson (1966) 'bottom-up' theory Also known as data-driven processing, because perception begins with the stimulus itself. It is a direct theory of perception Processing is carried out in one direction from the retina to the visual cortex.

Gregory (1970) Top-down processing refers to the use of contextual information in pattern recognition. It is a constructivist (indirect) theory of perception This is because the meaning of the surroundings provide a context to aid understanding.

Herring illusion The central spot in the appears to be further away than the edges. Because the heavy black lines are the same thickness at the centre as at the edges but are assumed to be further away, the brain thinks they must be more widely spaced at the centre.

Mueller-Lyer illusion The visual system detects the depth cues, which are usually associated with 3D scenes, and incorrectly decides it is a 3D drawing.

Necker cube When you stare at the crosses on the cube, the orientation can suddenly change, or 'flip'. It becomes unstable and a single physical pattern can produce two perceptions.

Your task Summarise and evaluate Gibson’s ‘bottom up’ Theory Summarise and evaluate Gregory’s ‘top down’ Theory Using your knowledge of Perceptual Theory, critically evaluate one of the following paintings.

Paula Rego – the Dance Discuss Rego’ s The Dance with reference to top down and bottom up perception

Wassily Kandinsky Swinging

Salvador Dali Autumnal Cannibalism

Hans Holbein the Younger The Ambassadors