ap psych 1.6a-d

sensation

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

sensory receptors

sensory nerve endings that respond to stimuli

perception

process by which our brain organizes and interprets sensory information, enabling us to recognize objects and events as meaningful

bottom-up processing

absorbtion of info

information processing that begins with the sensory receptors and works up to the brain’s integration of sensory information

top-down processing

interpretation of info

information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations

transduction

conversion of one form of energy into another

in sensation, the transforming of physical energy (sight, sound, smell) into neural impulses the brain can interpret

psychophysics

the study of relationships between the physical characteristics of stimuli (ex: intensity), and our psychological experience of them

absolute threshold

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

single detective theory

a theory predicting how and when we detect the presence of a faint stimulus/signal amid background stimulus/noise

assumes there is no single absolute threshold and that detection depends on a person’s experience, expectations, motivation, and alertness

subliminal

below one’s absolute threshold for conscious awareness

unconscious brain may react

priming

the unconscious activation of certain associations, thus predisposing one’s perception, memory, or response

difference threshold

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

increases with size of stimulus

Weber’s law

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

sensory adaptation

diminished sensitivity as a consequence of constant stimulation

doesn’t work on vision because eyes are always darting around

wave length

the distance from the peak of one light wave or sound wave to the peak of the next

hue

the dimension of color that is determined by the wavelength of light

intensity

determined by a wave’s amplitude/height

the amount of energy in a light wave or sound wave, which influences what we perceive as brightness or loudness

cornea

the eye’s clear, protective outer layer, covering the pupil and iris

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

retina

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

accomodation

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

myopia

near-sightedness

the lens focuses on a point in front of the retina

farsightedness

lens focuses on a point behind the retina

rods

retinal receptors that detect black, white, and gray, and are sensitive to movement

necessary for peripheral and twilight vision

multiple rods use a single bipolar cell

cones

retinal receptors that are concentrated near the center of the retina and that function in the daylight or well-lit conditions

detect fine detail and give rise to color sensations

each cone uses a single bipolar cell → this direct connection allows precision

optic nerve

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

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 cones cluster

optic chiasm

half of each eye’s information arrives in the opposite half of the brain

Young-Helmholtz trichromatic theory

the theory that the retina contains 3 different types of color receptors (one most sensitive to red, one to green, one to blue), which, whe stimulated in combination, can produce the perception of any color

opponent-process theory

the theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision

ex: some cells are stimulated by green and thus inhibited by red

feature detectors

nerve cells in the brain’s visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement

fusiform face area

right temporal lobe area that helps recognize faces from varied viewpoints

parallel processing

processing multiple aspects of a stimulus or problem simultaneously (ex: motion, form, depth, color)

prosopagnosia

facial blindness

audition

the sense or act of hearing

frequency

the number of complete wavelengths that pass a point in a given time

measured in hertz

pitch

a ton’es experiences highness or lowness, depending on frequency

sound intensity

measured in decibels

normal human conversation is 60 db, while 85+ db for a prolonged time causes hearing loss

middle ear

the chamber between the eardrum and the cochlea containing three tiny bones (malleus, incus, stapes) that concentrate the vibrations of the eardrum on the cochlea’s oval window

cochlea

a coiled, bony, fluid-filled tube in the inner ear

sound waves travelling through the cochlear fluid trigger nerve impulses

inner ear

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

sensorineural hearing loss

aka nerve deafness

the most common form of hearing loss

caused by damage to the cochlea’s receptor cells or auditory nerve

conduction hearing loss

less common form of hearing loss

caused by damage to the mechanical system that conducts sound waves to the cochlea (ear drum, middle ear bones)

cochlear implants

helps nerve deafness

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

place theory

aka place coding

in hearing, the theory that links the pitch we hear with the place where the cochlea’s membrane is stimulated

explains how we hear high-pitched sounds

frequency theory

aka temporal coding

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

supported by volley theory

volley theory

neurons can’t fire more than 1000 times per second, but can alternate firing to send the frequency of a tone that is more than 1000

touch sensations

pressure, warmth, cold, pain

gate-control theory

the theory that the spinal cord contains a neurological “gate” that blocks pain signals or allows them to pass on the brain

the “gate” is opened by the activity of pain signals travelling up small nerve fibers, and is closed by activity in larger fibers or by information coming from the brain

phantom limb sensations

people who were born without a limb or had one amputated can still feel pain or movement there

gustation

sense of taste

taste sensations

sweet, sour, salty, bitter, umami, oleogustus

olfaction

sense of smell

anosmia

unable to smell

kinesthesis

our movement sense

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

proprioceptors and vision help

vestibular sense

our balance sense

our sense of body movement and position that enables our sense of balance

inner ear’s fluid-filled semicircular canals and vestibular sacs are stimulated when your head moves → can cause dizziness if moving and suddenly stopped

sensory interaction

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

McGurk effect

hearing a sound while seeing a speaker mouth a different sound creates a third sound

embodied cognition

the influence of bodily sensations, gestures, and other states on cognitive preferences and judgments

synthesia

blend of sensations