Perception Mr. Koch AP Psychology Forest Lake High School

Perceptual Organization

Gestalt Theory German word meaning “form” or “whole” – Idea is that our perceptions are more than just a sum of the individual parts

Form Perception Figure & Ground – Organization of visual field into objects (figures) that stand out from surroundings (ground)

Form Perception Grouping – Tendency to organize stimuli into coherent groups Proximity – grouping nearby figures together Similarity – grouping similar figures Continuity – tendency to perceive smooth, continuous patterns – not discontinuous Connectedness – when uniform and linked, we perceive spots, lines, areas as single unit Closure – fill in gaps to create a complete, whole object

Depth Perception Binocular Cues – Depth clues based off use of 2 eyes “Retinal disparity” – computing distance based on amount of difference b/w two images » More disparity = closer “Convergence” – based on extent to which eyes converge inward

Depth Perception Monocular Cues – Distance cues available to a single eye Relative size – smaller images seem further away Interposition – objects blocking others appear closer Relative clarity – hazy objects seem further away Texture gradient – further objects appear to have fine, indistinct texture

Depth Perception Monocular cues (cont’d) Relative height – objects higher in field of vision appear further away Linear perspective – parallel lines appear to converge with distance Light and shadow – near objects reflect more light

Depth Perception Visual Cliff Experiment

Motion Perception Phi Phenomenon Take cues from things like changes in size Stroboscopic Movement

Perceptual Constancy Perceive objects as unchanging even as shape/size and lightness may change

Perceptual Interpretation

Sensory Deprivation & Restored Vision Blind learn by touch – If vision is restored, unable to identify objects previously identified by touch (sight and touch are different) Vertical/horizontal lines w/ kittens Suggests “critical period”

Perceptual Adaptation Ability to adapt to changed visual input i.e. – adapting w/ reversible glasses

Perceptual Set Mental predisposition to perceive one thing and not another Schemas – concept or framework that organizes/interprets info » Based on experiences Context effects – what we perceive depends on cultural perceptual set and immediate context of experiences ex: “Fish is Fish”