2.1 - Perception

Perception

The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Bottom-Up Processing

Sensory analysis that begins at the entry level, starting with sensory receptors and working up to the brain's integration of sensory information.

Top-Down Processing

Information processing guided by higher-level mental processes, such as expectations, context, and prior knowledge.

Gestalt Psychology

An approach in psychology emphasizing our tendency to integrate pieces of information into meaningful wholes or complete forms.

Closure

A Gestalt grouping principle stating that the brain fills in gaps to create a complete, whole object.

Schemas

Mental frameworks or concepts that organize and interpret information based on past experiences.

Figure-Ground

The organization of the visual field into objects (the figures) that stand out from their surroundings (the ground).

Perceptual Set

A mental expectation to perceive one thing and not another, influenced by schemas and context.

Grouping

The perceptual tendency to organize sensory stimuli into coherent groups based on principles like proximity, similarity, continuity, and closure.

Attention

The allocation of conscious cognitive processing resources toward specific sensory inputs or internal thoughts.

Proximity

A Gestalt grouping rule stating that objects near each other tend to be grouped together.

Selective Attention

The focusing of conscious awareness on a particular stimulus while filtering out other competing stimuli.

Similarity

A Gestalt grouping rule stating that objects that look alike tend to be grouped together.

Cocktail Party Effect

The ability to focus conscious attention on a single voice among a noisy crowd while still unconsciously monitoring background chatter for relevant stimuli like one's name.

Inattentional Blindness

Failing to see visible objects when our attention is directed elsewhere.

Change Blindness

A form of inattentional blindness in which an individual fails to notice significant changes in the visual environment.

Depth Perception

Brain's ability to see the world in three dimensions (3D) and judge distances, converting flat, two-dimensional (2D) retinal images into spatial awareness

Visual Cliff

A laboratory device used to test depth perception in infants and young animals.

Binocular Cues

Depth cues, such as retinal disparity and convergence, that depend on the visual input of both eyes.

Convergence

A binocular depth cue involving the inward neuromuscular movement of the eyes (cross-eyed) when focusing on a close object.

Retinal Disparity

A binocular depth cue that compares images from the retinas of both eyes to calculate distance; the greater the difference between the two images, the closer the object.

Monocular Cues

Depth cues available to either eye alone, such as relative size, interposition, and linear perspective.

Relative Clarity

A monocular depth cue where clearer objects are perceived as closer than hazy or blurry objects.

Relative Size

A monocular depth cue where—if two objects are assumed to be similar in size—the object that casts a smaller image on the retina is perceived as being farther away.

Texture Gradient

A monocular depth cue where objects up close look highly detailed and sharp, but look blurry, dense, and blended together as they get farther away.

Linear Perspective

A monocular depth cue where parallel lines appear to converge with increasing distance.

Interposition

A monocular depth cue where an object that partially blocks our view of another object is perceived as closer.

Perceptual Constancies

Perceiving objects as unchanging in size, shape, brightness, and color even as illumination and retinal images change.

Color Constancy

Perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object.

Perceptual Adaptation

The ability of the brain to adjust to an artificially displaced or inverted visual field.

Apparent Motion

The perception of movement when no physical movement is occurring, generated through rapid successions of static images or lights.

Stroboscopic Movement

A type of apparent movement produced by displaying a rapid series of slightly varying still images.

Phi Phenomenon

An illusion of movement created when two or more adjacent lights blink on and off in quick succession.