Topic 2.1 Perception

Difference between perception and sensation

Perception is how we interpret info from 5 senses. Sensation is the actual data from our sensory receptors.

Top Down Processing

When you use prior knowledge and experience to interpret info which helps process things fast but can lead you astray

Proofreaders Illusion

For example, trying to proofread your essay but missing simple mistakes because you know what you meant to write

Bottom Up Processing

When stimuli or experience is not familiar so you have to build perception by organizing info as it comes in and use context clues

Schema

Mental framework built from past experiences. (Ex: like when you can picture a birthday party that you haven’t gone to yet)

Perceptual Set

A mental shortcut the brain uses to quickly interpret what you’re experiencing

Selective Attention

Focusing on a particular stimuli and ignoring everything else in our environment

Cocktail Party Effect

The brain continues to monitor the environment for relevant information (Ex: hearing your name)

Inattentional Blindness

Failure to notice something in our environment because we aren’t paying attention to it but it’s still there

Change Blindness

Failure to notice a change in our environment because of divided attention

Apparent Movement

Perceiving motion even though nothing is actually moving

Stroboscopic Movement

Series of images moving in rapid succession (Ex: animation)

Phi Phenomenon

Blinking lights that are perceived as moving even though objects are stationary (ex: those Christmas lights that rich people have)

Induced Movement

When a stationary object appears to be moving b/c of surrounding objects

Autokinetic Effect

Stationary point of light in a dark environment appears to move

Gestalt Principle: Figure & Ground

Describes how our visual system separates what we see into two categories

Gestalt Principle: Continuation

Our eyes naturally follow continues lines or paths

Gestalt Principle: Closure

Brain subconsciously fills in missing info when viewing a familiar but incomplete object

Gestalt Principle: Similarity

Refers to how we group similar objects or patterns together as one unit (ex: white circles and pink circles)

Gestalt Principle: Proximity

When objects are placed together, they are perceived as a single group and when they are spread out, they are seen as separate entities

Gestalt Principle: Symmetry

Objects that are symmetrical to each other can be perceived as a whole object

Binocular Cues

Both eyes working together (use retinal disparity for depth perception)

Monocular Cues

Require only one eye to perceive flat or 2D surfaces

Difference between convergence and retinal disparity?

Convergence refers to the eyes moving inward to focus on one object. Retinal disparity is each individual eye seeing a slightly different image

Monocular Cue: Relative Size

Objects closer to us appear larger and objects farther away appear smaller

Monocular Cue: Interposition

Objects blocked by another object are most likely far away

Monocular Cue: Relative Height

Objects higher in our visual field appear father away

Monocular Cue: Shading & Contour

Parts of an image that are hazy with less detail appear far away

Monocular Cue: Texture & Gradient

Objects clear, in focus, full of detail appear closer than blurry ones

Monocular Cue: Linear Perspective

When parallel lines seem to converge (meet) in the distance

Monocular Cue: Motion Parallax

Objects nearby seems to go fast (ex: cars on freeway) and objects far away looks slow (ex: clouds in sky)

Perceptual Constancy

Ability to perceive objects as a consistent shape (shape constancy), size (size constancy), color (color constancy), and lightness (lightness constancy) even when appearance changes b/c of varying conditions