Unit 2. Cognition - Pt 1. Perception

Bottom-up processing

Perception based on external sensory input

Top-down processing

Perception shaped by prior knowledge or expectations

Schemas

Mental frameworks from past experience that filter and interpret sensory info

Belief and memory

Internal factors influencing what and how we perceive

Context, experience, and culture

External factors influencing what and how we perceive

Gestalt Perceptual principles

Closure; Figure and ground; Proximity; Similarity

Closure

We fill in gaps to perceive whole objects

Gestalt Perceptual principles

Figure-ground

We distinguish objects (figures) from their backgrounds (grounds)

Gestalt Perceptual principles

Proximity

We group objects that are close together

Gestalt Perceptual principles

Similarity

We group similar-looking items

Gestalt Perceptual principles

Attention

Influenced by both internal (e.g., schemas) and external (e.g., noise) processes

Cocktail party effect

Ability to focus attention on specific stimuli (e.g., hearing your name in a noisy room)

Attention

Change blindness

Failure to notice visual changes in the environment when not paying attention

Attention

Monocular Depth Cues

visual clues that help us perceive depth using only one eye

Retinal disparity

The difference between images from each eye

monocular depth cues

Convergence

Inward angle of eyes when focusing on something close

monocular depth cues

Binocular Depth Cues

visual cues that use both eyes to perceive depth and create a three-dimensional image of the world

Relative clarity

Distant objects appear hazier

binocular depth cues

Relative size

Smaller image = farther away

binocular depth cues

Texture gradient

More texture = closer object

binocular depth cues

Linear perspective

Parallel lines seem to converge in the distance

binocular depth cues

Interposition

One object blocking another = closer

binocular depth cues

Retinal disparity/Convergence

monocular depth cues

Relative clarity/Relative size/Texture gradient/Linear perspective/Interposition

binocular depth cues

Visual perceptual constancy

We perceive objects as stable even when their appearance changes (e.g., size, shape, or brightness changes due to angle or lighting)

Apparent motion

We perceive motion where there is none, such as lights blinking on/off in sequence (phi phenomenon)