AP Psych Sensation and Perception

Sensation

Detecting physical energy from environment and converting it into neural signals

Perception

Selection, organization, interpretation of sensations

Psychophysics

Study between relationship between physical characteristics of stimuli and out psychological experience with them

Absolute Threshold

Minimum stimulation needed to detect a particular stimulus 50% of the time

Subliminal Threshold

When stimuli is below one’s absolute threshold for conscious awareness

Difference Threshold

Minimum difference between two stimuli required for detection 50% of the time

AKA the just noticeable difference (JND)

Weber’s Law

Two stimuli must differ by a constant minimum percentage to be percieved as different

Signal Detection Theory

Predicts how and when we detect a faint stimulus amind background noise

Assumes that there is no absolute threshold and detection depends on person’s experience, expectation, motivation, and level of fatigue

Sensory Adaptation

Constant stimulation = diminished sensitivity

How vision works

Lights received through cornea, then the pupil, then the lens focuses light on retina, rods and cones send signals to thalamus via optic nerve, signals distributed to rest of brain, mainly visual cortex

sensory transduction

transformation of stimulus energy into neural impulses

photo transduction

conversion of light energy into neural impulses that the brain can understand

hue

determined by wavelength (peak to peak) of light

diff wavelengths of lights result in diff colors

intensity (brightness)

amount of energy in wave, determined by amplitude

cornea

transparent tissue where light enters eye

iris

muscle that expands and contracts to change size of opening (pupil) for light

lens

focuses light rays on retina

changes shape to focus near or far images on retina

retina

contains sensory receptors that process visual info and sends to brain

contains recepetor cells such as rods and cones, and neurons that process visual info

a misshapen eyeball causes

nearsightedness or far

rods

process black and white and night vision

cones

process color and detail

blind spot

point where optic nerve leaves eye where no receptor cells are located

feature detection

nerve cells in visual cortex respond to specific features, such as edges, angles, and movement

shape detection

temporal lobe activity occurs as people look at chairs, faces, shoes, houses

shape and feature detection

brain uses both to perceive patterns

parallel processing

brain processes several aspects of stimulus simultaneously

trichromatic theory

helmholtz, normal retina contain receptor cells that are sensitive to red, blue, and green colors

colorblindness supports theory

opponent process theory

hering, we process four primary colors combined in pairs of red-green, blue-yellow, and black-white

color constancy

color of an object remains the same under diff illusions

when context changes, the color of an object may look diff

hearing

process by which sound waves enter outer ear through the auditory canal to eardrum

eardrum transmits vibration to cochlea

membrane vibrated by stirrup, jostles cochlear fluid, ripples across basilar membrane

triggers nerve cells, sends to thalamus, sent to auditory cortex

transduction

the convergence of energy into diff form

acoustical transduction

conversion of sound waves into neural impulses

place theory

sound frequencies stimulate basilar membrane at specific pitches resulting in perceived pitch

best explains sensing high pitches

frequency theory

rate of nerve impulses traveling up auditory nerve matches the frequency of tone, enabling us to sense pitch

best explains sensing low pitches

localization of sounds

sound reach one ear faster than other, causing us to localize the sound

conduction hearing loss

damage to the mechanical system that conducts sound waves to cochlea

sensorineural hearing loss

caused by damage to cochlea’s receptor cells or to the auditory nerve, also called nerve deafness

more common

nociceptors

receptor cells that detect diff types of pain: temp, pressure, chem

gate control theory

spinal cord contains neurological “gates” that either block pain or allow to be sensed

pain control

drugs, surgery, acupuncture, exercise, hypnosis, or thought distraction

divided consciousness theory

hypnosis is state of divided consciousness

social influence theory

hypnotic subjects are just imaginative actors playing social role

taste

sweet, salty, bitter, savory, umami

olfaction

odors enter nasal cavity then go to olfactory bulb to sense smell

neuro matrix theory

pain originates in brain

this came after phantom pain

smell and memories

brain region for smell involved with regions for memories (limbic system)

kinesthesia

sense of position regarding body and its parts

vestibular sense

monitors head position and movement

balance management

semicircular canals and vestibular sacs contains fluids when head rotates and tilts

stimulates hair like receptors which send messages to cerebellum to determine balance and stability

sensory interaction

when one sense affects another

synesthesia

where one sensation produces another

selective attention

the conscious focus on one stimulus among many

cocktail party effect

inattentional blindness

not noticing stimuli when focused on others

change blindness

failing to notice changes in environment, especially when focuing our conscious thought on a signle stimuli

sensory adaptation

diminished sensitiviity as a result of constant stimulation

gestalt psychology

the study of how people organize the world visually into meaningful units and patterns

gestalt psych form perception

organize field into 2 parts

• field: what stands out

• ground: the background

gestalt principle of proximity

if things are closed together, tend to be grouped together

gestalt principle of closure

in order to complete forms, the brain fills in the gap

gestalt principle of similarity

things that are alike in some way are percived as being together

gestalt princuple of continuity

lines and patterns tend to percived as continuing in time or space

gestalt principle of connectedness

things that are alike tend to be perceived as being the same unit

what does depth perception allow us to do

judge distances

binocular cues: retinal disparity

images from 2 eyes differ

binocular cues: convergence

ability for eyes to move closer to nose (inward) to see near objects or away frok nose (outward) to see farway objects

monocular cues: phi phonomenon

when lights flash at certain speed, they tend to present illusions of motion/moving

monocular cues: perceptual constancy

perceiving objects as unchanging even as illumination and retinal images changes

includes constancies of shape and size

monocular cues: size constancy

stable size perception amid changing size of stimuli

monocular cues: size-distance relationship

things appear bigger bc distance cues

perceptual adaptation

visual ability to adjust to an artifically adjusted visual dield

interposition

objects that block others appear to be closer

linear perspective

parallel lines appear to converge with distance

more converge more perceived distance

relative height

something higher in your visual field is percived as higher away

texture gradient

texture is less aparant the firther away an object appears

motion parallax

objects that are closer appear to move faster than objects that are further

stroboscopic motion

appearance or lack of motion that occurs when stimulus is not viewed continuisly but in diff seperate stages

perceptual set

mental predisposition to percive one thing and not the other

schemas

concepts that organize and interpret unfamilar info

face schemas are accentuated by diff features on face