Sensation & perception

Bottom-up processing

information from our environment that we take in via 5 senses (process of transduction)

Top-down processing

High level processing using our previous expectations/ experiences to interpret sensory experiences

selective attention

focusing conscious awareness on a particular thing

inattentional blindness

failing to see visible objects when attention is directed elsewhere

prosopagnosia

inability to recognize/differentiate faces, vision okay but perception impaired

sensation

process by which sensory receptors & nervous system receive & represent stimulus energies from our environment

perception

process of organizing & interpreting sensory info, enabling us to recognize objects & events

cocktail party effect

ability to attend to one’s attention among many

change blindness

failing to see visible objects when your attention is directed somewhere else

transduction

conversion of one form of energy into another

psychophysics

study of relationships between physical characteristics of stimuli like intensity & our psychological experience of them

absolute threshold

minimum stimulation needed to detect stimulus 50% of the time

signal detection theory

predicts when we detect weak signals, assume no absolute threshold & detection depends on person’s experience, expectations, motivation, and alertness

subliminal

below one’s absolute threshold for conscious awarness

prime

unconscious activation of certain associations like predisposition of perception, memory, or response

difference threshold

minimum difference between 2 stimuli require for detection 50% of the time (noticeable difference)

weber’s law

for average person to receive a difference 2 stimuli must differ by constant minimum percentage (not constant amount)

sensory adaptation

diminished sensitivity after constant exposure to a stimulus that doesn’t change

perceptual set

seet of mental tendencies/ assumptions that greatly effects (top-down) what we perceive

schema

framework based on prior experiences

context effects

the setting (surrounding info) often influences the way we perceive things

ESP (extra sensory perception)

telepathy, clairvoyance, and precognition these don’t exist in any scientific, factual way

emotion & motivation

perceptions are influenced by expectations, context, emotion, and motivation

telepathy

mind-to-mind communication

clairvoyance

perceiving remote events

precognition

perceiving future events

psychokinesis

“mind over matter” (levitating table)

parapsychology

study of paranormal phenomena

wavelength

distance from one peak to the next

hue

dimension of color

intensity

amount of light energy in light waves determines by amplitude of height of wave

amplitude

height of wave

cornea

protects eye and bends light to provide focus when light enters

pupil

light passes through, adjustable opening in center of the eye where light enters

retina

light sensitive inner surface of the eye that contains receptor rods, cones, and neurons

accomidation

process when the lens changes shape/curvature to focus near/far objects on retina

rods

retinal receptors that detect black, white, & gray peripheral vision

cones

colored vision & fine detail

bipolar cells

activated by chemical changes that spark neural signals from light energy

ganglion cells

fibers that make up the optic nerve

optic nerve

carries neural impulses from eye to brain

blind spot

where the optic nerve leaves eye creating a spot where there are no receptor cells

fovea

central focal point in the retina where cones cluster

feature detectors

nerve cells in brain that respond to specific features of stimulus like shape, angle, or movement

parallel processing

processing many aspects at once

young-helmholtz trichromatic theory

retina has 3 color receptors sensitive to red, green, and blue. Stimulation of combinations of these produces perception of any color

afterimages

image that continues to appear in eyes after a period of exposure to the original image

opponent-process theory

idea that cells in visual system process colors in complementary pairs (red/green, yellow/blue)

gestalt

organized whole, german psychologists emphasized our tendency to integrate pieces of info into a whole.

necker cube

individual elements of a figure

figure ground

organization of visual fields in to objects (figures) that stand out from surroundings (ground)

grouping

tendency to organize stimuli into coherent groups

proximity

we group nearby figures together (we don’t see 6 seperate lines we see 3 sets of 2 lines)

continuity

we perceive smooth patterns rather than discontinuous ones

closure

we fill in gaps to create a complete, whole object

depth perception

ability to see objects in 3-D even though images that his retina are in 2-d, allows us to judge distance

visual cliff

device for testing depth perception on infants, small children, and young animals

binocular cues

depth cues that depend on using both eyes

retinal disparity

binocular cue for perceiving depth , difference between 2 images, the closer the object.

monocular cues

depth cues, interposition and linear perspective either eye alone

relative height

distant objects seem smaller & higher in relation to items that are closer

relative motion

speed/motion of an object in respect to a specific point

relative size

perceptual clue that allows you to determine how close an object is in comparison to an object of a known size

interposition

when objects overlap each other, enables judgement or relations & perceives depth

linear persepctive

perceive depth when we see 2 parallel lines that seem to connect in an image

light & shadows

used by visual system as cues to determine depth perception & distance

stroboscopic movement

phenomenon that the brain perceives continuous movement in rapid series slightly varying images

phi phenomenon

illusion of movement created when 2+ adjacent lights blink on and off quickly

perceptual constancy

perceiving objects as unchanging even as changes in angle, perspective, distance, etc occur

color constancy

perceiving objects as having constant color even as changes in angle perspective, distance, etc occur

brightness constancy

perceiving an object has constant brightness even while illumination varied

relative luminance

amount of light an object reflects relative to its surroundings

shape constancy

perceive forms of familiar objects as constant even while reinas reviebe changing images

size constancy

perceive objects as having constant size even while our distance from them varies

moon illusion

moon looks up to 50% bigger when near horizon vs in sky

critical period

crucial time for normal sensory and perceptual brain development

perceptual adaptation

ability to adjust to changed visual input/ inverted visual field/artificially displaced

audition

sense or act of hearing

amplitude

height of soundwave determines its loudness

frequency

length and # of complete wavelengths that determines pitch

pitch

a tones highness/lowness; depends on frequency

decdibles

unit of measurement for sound

outer ear

transformation of vibrating air into nerve pulses decoded aas sounds by the brain begins here

eardrum

tiny membrane that vibrates from soundwaves

middle ear

channel between ear drum & cochlea containing 3 tiny bones, picks up vibrations and transmits them to cochlea

hammer, anvil, stirrup

3 tiny bones in middle ear that pick up vibrations

cochlea

snail-shaped tube in inner ear, sound waves travel through cochlear fluid triggering neural impulses

inner ear

innermost part of the ear, contains cochlea, semicircular canals & vestibular sacs

oval window

cochlea’s membrane (vibrates from incoming vibrations)

basilar membrane

jostling fluid that fills tube and creates a ripple in basilar membrane, bends hair cells lining its surface, triggers impulses

auditory nerve

sends nerual messages via thalamus to the auditory cortex

auditory cortex

in brain’s temporal lobe

cilia

hairline vibrating structure, helps clean wax buildup & monitor fluid in the ear

conduction hearing loss

hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea

sensorineural hearing loss

hearing loss caused by damage to cochlea’s hair cell receptors or auditory nerves

cochlear implant

electronic device that translates sounds into electrical signals stimulating auditory nerves

perceiving loudness

brain interprets loudness from the number of activated hair cells

place theory

hear different pitches because different sound waves trigger activity in different places in the cochlea’s basilar membrane

volley principle

place theory best explains how we sense high pitches

locating sounds

2 ears better than 1, intensity difference & time lag are very small, 3-D hearing