psych (3. sensation and perception)

sensation

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

* receiving/converting/transmitting raw sensory to brain

perception

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

* selecting/organizing/interpreting sensory

selective attention

the focusing of conscious awareness on a particular stimulus.

bottom-up processing

starts at the sensory receptors and works up to higher levels of processing.

aka feature analysis, stimulus analysis starts with sense receptors -> brain/mind (break down -> features), takes longer but more accurate

top-down processing

constructs perceptions from the sensory input by drawing on our experience and expectations.

info processing guided by perceptions/experience

cocktail party effect

your ability to attend to only one voice among many

inattentional blindness

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

* ex. prompt to look somewhere/at something

change blindness

failing to notice changes in the environment.

* more likely to pay attention to more dramatic changes/movement

transduction

conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret

choice blindness

failure to recall choice immediately after making choice

all of our senses…

• receive sensory stimulation, often using specialized receptor cells.

• transform that stimulation into neural impulses.

• deliver the neural information to our brain.

psychophysics

the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.

schema

file cabinet for organizing thoughts

signal detection theory

how and when we detect the presence of a faint stimulus (signal) amid background noise (other stimulation, noise) -> experience, expectation, motivation, fatigue

* opposes absolute theory

* signal + noise

absolute threshold

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

* when i detect a sensation (ex. dimming light)

difference threshold

minimum difference between two stimuli required for detection 50% of the time, aka just noticeable difference (jnd)

subliminal

below one’s absolute threshold for conscious awareness.

priming

the activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response.

weber’s law

the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount).

sensory adaptation

diminished sensitivity as a consequence of constant stimulation.

perceptual set

a mental predisposition to perceive one thing and not another.

* flipping back and forth in an optical illusion

context effects

context affects perception and meaning

* ex. cultural background

extrasensory perception (esp)

the controversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition.

* DO NOT NEED TO KNOW

parapsychology

the study of paranormal phenomena, including esp and psychokinesis.

* DO NOT NEED TO KNOW

wavelength

peak-to-peak

* light or sound wave

* phase one, gathering light (waves)

examples of sensory → perception

light -> brightness

sound -> volume

pressure -> weight

sugar -> sweet

hue

color from wavelength

* ex. red, green, blue

intensity

the amount of energy in a light or sound wave

* amplitude of wavelength

pupil

the adjustable opening in the center of the eye through which light enters.

iris

a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening.

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina.

retina

the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information.

accommodation

the process by which the eye’s lens changes shape to focus near or far objects on the retina.

rods

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don’t respond.

cones

retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.

optic nerve

the nerve that carries neural impulses from the eye to the brain.

bipolar cells

light energy triggers chemical changes that would spark neural signals, activating nearby bipolar cells

ganglion cells

form the optic nerve, activated by bipolar nerves

blind spot

the point at which the optic nerve leaves the eye, creating a “blind” spot because no receptor cells are located there.

fovea

the central focal point in the retina, around which the eye’s cones cluster.

feature detectors

nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.

* specialized neurons, pass information to supercell clusters for complex patterns

parallel processing

the processing of many aspects of a problem simultaneously

* vs. serial/step-by-step

color theories

“that color is anything but that color” because it absorbs every other wavelength

* color processing occurs in two stages, yht theory first, then op theory (afterimage)

young-helmholtz trichromatic (three-color) theory

the theory that the retina contains three different color receptors—rbg—which, when stimulated in combination, can produce the perception of any color.

opponent process theory

the theory that opposing retinal processes (rg, yb, wb) enable color vision. ex, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.

gestalt

an organized whole.

* integrate parts and pieces to a whole

figure-ground

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

grouping

the perceptual tendency to organize stimuli into coherent groups.

proximity

group nearby figures together

ex. 3 × 2 rather than 6 * 1 (separate)

continuity

smooth, continuous patterns rather than discontinuous ones

* semicircles up and down a line resemble a sin function, wavy line

closure

fill in gaps to create a complete, whole object

depth perception

the ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance.

visual-cliff

a laboratory device for testing depth perception in infants and young animals.

* ex. glass, or optical illusion of drop in height

binocular cues

depth cues, such as retinal disparity, that depend on the use of two eyes.

retinal disparity

a binocular cue for perceiving depth: by comparing images from the retinas in the two eyes, the brain computes distance— the greater the disparity (difference) between the two images, the closer the object.

monocular cues

depth cues, such as interposition and linear perspective, available to either eye alone.

phi phenomenon

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

perceptual constancy

perceiving objects as unchanging (having consistent shapes, size, 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.

brightness constancy

aka lightness constancy, we perceive an object as having a constant brightness even while its illumination varies

relative luminance

the amount of light an object reflects relative to its surroundings

shape constancy

we perceive the form of familiar objects as constant even while our retinas receive changing images of them.

size constancy

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

perceptual adaptation

in vision, the ability to adjust to an artificially displaced or even inverted visual field.

* regaining balance after dizziness

pitch

a tone’s experienced highness or lowness; depends on frequency.

frequency

the number of complete wavelengths that pass a point in a given time (for example, per second).

outer ear

visible outer ear channels the waves through the auditory canal to the eardrum, a tight membrane, causing it to vibrate

middle ear

the chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window.

inner ear

the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs.

cochlea

a coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses.

sensorineural hearing loss

hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves; also called nerve deafness.

conduction hearing loss

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

muller lyer illusion

stick + arrow illusion

* open/closed fins make the line seem longer/shorter

convergence

as an object comes closer, your eyes have to converge in focus to see it

cochlear implant

a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea.

place theory

in hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch.

frequency theory

in hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch.

nociceptors

sensory receptors that detect hurtful temperatures, pressure, or chemicals

gate-control theory

the theory that the spinal cord contains a neurological “gate” that blocks pain signals or allows them to pass on to the brain. The “gate” is opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain.

tastes (+ survival functions)

sweet → energy source

salty → sodium essential to physiological processes

sour → potentially toxic acid

bitter → potential poisons

umami → proteins to grow and repair tissue

anosmia

inability to smell

taste receptors

taste buds (chemosensory receptors) contain basal cells, which differentiate into taste receptor cells (trcs) and perceive taste with microvilli (hairs) + send info by axon to the brain

olfaction

smell

* you inhale something of whatever or whoever it is you smell

memory stimulation

refers to activities or techniques designed to enhance and improve memory function. memory stimulation activities can include various strategies aimed at enhancing different stages of the memory process, such as encoding, storage, and retrieval.

* NOT IN THE TEXTBOOK, ON THE GUIDE

kinesthesia

the system for sensing the position and movement of individual body parts.

vestibular sense

the sense of body movement and position, including the sense of balance.

sensory interaction

the principle that one sense may influence another, as when the smell of food influences its taste.

interposition

if one object partially blocks our view of another, we perceive it as closer.

embodied cognition

in psychological science, the influence of bodily sensations, gestures, and other states on cognitive preferences and judgments.

quality

timbre

vision

light waves striking the eye

rods and cones in the retina

hearing

sound waves striking the outer ear

cochlear hair cells in the inner ear

touch

pressure, warmth, cold, pain on the skin

skin receptors detect pressure, warmth, cold, and pain

smell

chemical molecules breathed in through the nose

millions of receptors at the top of nasal cavity

body position— kinesthesia

any change in position of a body part, interacting with vision

kinesthetic sensors all over the body

body position— vestibular sense

movement of fluids in the inner ear caused by head/body movement

hairlike receptors in the semicircular canals and vestibular sacs

localization of sounds

sounds that reach one ear faster than the other ear cause us to localize the sound (where it comes from)

critical period

in early development in particular, certain factors must be present at specific ages for growth to occur normally.

acuity

sharpness of vision

cornea

outer covering of the eye