AP Psychology - Unit 2.1 Perception

Perception

• how an individual sees and understands the world around them

• how an individual interprets sensory information

Sensation

• detecting a stimulus

• involves our 5 senses (sight, hearing, taste, touch, and smell)

Top-Down Processing

• involves using prior knowledge and experiences to interpret sensory information

• allows us to quickly make sense of what we are experiencing

• influences how we perceive a stimulus

• may cause us to come to some faulty conclusions

Proofreader’s Illusion

• occurs when an individual misses spelling or grammar mistakes when reading over a paper

• great example of how our expectations can shape or distort what we perceive

Bottom-Up Processing

• used when we come across a stimulus or experience that is complex and not familiar to us

• this process often takes longer, since we are building our perception from the ground up

• organizing and interpreting sensory information as it comes in

Schemas

• mental templates that help the brain organize sensory information

• built from past experiences

• gives us a general guide on how we should understand and respond to the world by fitting new information into pre-existing categories

• operate over long periods of time, but are constantly updated

Perceptual Set

a mental shortcut the brain uses to quickly interpret what an individual is experiencing

influences our immediate perception

affects how we interpret a stimulus in a specific moment

influenced by;

• experiences

• motivation

• emotions

• context

Context

• all environmental factors

Motivation

• our energy or desire to accomplish something

Emotion

• our feelings/arousal

Gestalt Psychology

• focuses on how humans naturally group elements together to form meaningful patterns

• our brains tend to interpret a stimuli as a unified whole rather than individual components

• “perceptual wholes”

Figure and Ground

• our visual system breaks down images into two categories

• helps us quickly identify important information while filtering out the rest

Figure

• object of focus

Ground

• background

Closure

• states that our brain subconsciously fills in missing information when viewing a familiar but incomplete object

Similarity

• refers to how we perceive a group of similar objects or patterns as one cohesive unit

Anomaly

• occurs when an object is different from other objects

• become focal points

Proximity

• states that when objects are placed close to each other, they are often perceived as a single group

• objects that are spaced farther apart are seen as separate entities

Continuation

• states that our eyes will continue following continuous lines or paths

Symmetry

• when objects are symmetrical to each other, we often perceive them as one object rather than individual, separate elements

Perceptual Constancy

• we perceive objects as remaining unchanged even as characteristics of the stimuli are changing

Color Constancy

•  allows us to perceive objects as having consistent color, even if changes in illumination alter the wavelengths reflected by the object

Shape Constancy

• allows us to perceive the form of familiar objects as constant, even while our retinal images of them change

Size Constancy 

• allows us to perceive an object as having the same size, even when its distance from us varies

Depth Perception

• the ability to see objects in three dimensions, even if the image that strikes the retina is two-dimensional

• allows us to perceive the relative distance of an object in our visual field

Binocular Cues

• depth cues that depend on the use of two eyes

Visual Cliff

device used to test depth perception in infants and young animals

a model of a cliff that seems to have a “drop-off”

• the “drop-off” is an area covered by a transparent material

Convergence

• binocular cue

• the process of our eyes turning inward to view an object in a nearby distance

• enabled by the brain combining the two retinal images

Retinal Disparity

• binocular cue

• the difference between the two images that the eyes create when viewing an object

• caused by the space in between the eyes

• the greater the disparity/difference, the closer the object

Monocular Cues

• depth cues that only rely on one eye

Relative Height

monocular cue

• objects higher in our visual field appear farther away

• objects lower in our visual field seem closer

Light and Shadow

monocular cue

object that is able to cast a shadow is three-dimensional

nearby objects reflect more light to a person’s eyes than more distant objects

• an object that is dim will be perceived as being farther away

Relative Size

monocular cue

allows us to determine how close an object is to us

• objects that are closer appear larger

• objects that are farther away will appear smaller 

Interposition

monocular cue

occurs when one object blocks another

• the object that is blocking our view of another is perceived as closer

Linear Perspective

monocular cue

parallel lines seem to converge in the distance

• gives us a sense of depth and positioning

Texture Gradient

monocular cue

occurs when our perspective of an object's smoothness and texture changes when we move towards or away from it

• objects that are full of detail appear closer

• objects that lack detail or are smooth appear farther away

Relative Clarity

monocular cue

occurs because more light passes through objects that are farther away

• distant objects are perceived as hazy and blurry

• nearby objects appear clear and sharp

Relative Motion/Motion Parallax

monocular cue

can be influenced by an individual’s own movement (ex: if you’re in the car)

• closer objects appear to move quickly

• farther objects seem to move more slowly or remain stationary

Selective Attention

occurs when an individual focuses their conscious awareness on a particular stimuli

• causes them to tune out other stimuli in the environment

Cocktail Party Effect

auditory selective attention

the ability to stay focused on one voice in a party environment while being subconsciously aware of background noise

• subconscious awareness enables an individual to detect an auditory stimuli that is personally significant

Inattentional Blindness

• the failure to notice stimuli in our visual field due to our attention being drawn elsewhere

Change Blindness

• a type of inattentional blindness

• we fail to notice changes in the environment

Apparent Movement

• occurs when the brain perceives motion, even though nothing is actually moving

• visual cues and timing can end up tricking the brain into perceiving the movement of an object

Attention

conscious awareness

• includes focus and concentration

Stroboscopic Motion

• illusion of continuous movement that is experienced when viewing a rapid series of slightly varying still images

• used in animations and films

Phi Phenomenon

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

Induced Movement

• a stationary objects appears to move because of the motion of surrounding objects

Autokinetic Effect

• the illusory movement of a stationary spot of light in a dark environment