Chapter 5. Key Terms

absolute threshold

minimum amount of stimulus energy that must be present for the stimulus to be reliably detected

afterimage

continuation of a visual sensation after removal of the stimulus

amplitude

height of a wave

basilar membrane

floor of the cochlea, which contains the hair cells (sensory receptors for the auditory system)

binaural cue

two-eared cue to localize sound

binocular cue

cue that relies on the use of both eyes

binocular disparity

each eye receives a slightly different view of the world

blind spot

point where optic nerve leaves eye – has no receptors therefore we are unable to respond to visual information falling on this part of the eye

bottom-up processing

system in which perceptions are built from sensory input

closure

organizing elements into complete objects rather than as a series of parts

cochlea

fluid-filled, snail-shaped structure that contains the sensory receptor cells of the auditory system

cochlear implant

electronic device that consists of a microphone, a speech processor, and an electrode array to directly stimulate the auditory nerve to transmit information to the brain

conductive hearing loss

failure transmit sound to the auditory receptors (hair cells)

cone

specialized photoreceptor that works best in bright light conditions and detects color

congenital deafness

deafness from birth

congenital insensitivity to pain (congenital analgesia)

genetic disorder that results in the inability to experience pain from birth

cornea

curved transparent covering over the iris

deafness

partial or complete inability to hear

decibel (dB)

logarithmic unit of sound intensity

depth perception

ability to perceive distance and see in 3-D

figure-ground relationship

how we decide what is in front (figure) and background (ground) in our world

fovea

central part of the retina that we use when we look directly at a visual object, this area contains only cones

frequency

number of waves in a time period

Gestalt psychology

field of psychology based on the idea that the whole is different from the sum of its parts

good continuation

(also, continuity) we are more likely to perceive lines as continuous and smoothly flowing lines rather than jagged and broken

hair cell

auditory receptor cell of the inner ear

hertz (Hz)

cycles per second; measure of frequency of sound waves

inattentional blindness

failure to notice something that is completely visible because of a lack of attention

incus

middle ear ossicle; also known as the anvil

inflammatory pain

signal that some type of tissue damage has occurred

interaural level difference

sound coming from one side of the body is more intense at the closest ear because of the attenuation of the sound wave as it passes through the head

interaural timing difference

small difference in the time at which a given sound wave arrives at each ear

iris

colored portion of the eye

just noticeable difference

smallest difference between two stimuli required to detect that they are different

kinesthesia

perception of the body’s movement through space

lens

curved, transparent structure that provides ability to change focus from near back to distance

linear perspective

two parallel lines converge to give perception of depth – monocular cue

malleus

middle ear ossicle; also known as the hammer

Meissner’s corpuscle

touch receptor in skin that responds to light changes in pressure (but not sustained pressure)

Merkel’s disk

touch receptor that responds to sustained light touch

monaural cue

one-eared cue to localize sound

monocular cue

cue that requires only one eye – often in context of depth perception

neuropathic pain

pain from damage to neurons of either the peripheral or central nervous system

nociception

sensory signal indicating potential harm and maybe pain

olfactory bulb

bulb-like structure under the frontal lobe processes information about smell from nose

olfactory receptor

sensory cell for the olfactory system

opponent-process theory of color perception

color is coded in opponent pairs: black-white, yellow-blue, and red-green

optic chiasm

X-shaped structure that sits just below the brain’s ventral surface; represents the merging of the optic nerves from the two eyes and the separation of information from the two sides of the visual field to the opposite side of the brain

optic nerve

axons that carry visual information from the retina to the brain

Pacinian corpuscle

touch receptor that detects changes in deep pressure

pattern perception

ability to discriminate among different figures and shapes

perception

way that sensory information is interpreted and consciously experienced

perceptual hypothesis

prediction used to explain how we interpret sensory information

pheromone

chemical message secreted by one individual that affects behavior and physiology of another

photoreceptor

cell that detects light and converts it into neural energy

pinna

visible part of the ear that protrudes from the head

pitch

perception of the frequency of a sound

place theory of pitch perception

different portions of the cochlea are sensitive to different sounds of specific frequencies

principle of closure

organize elements into complete objects, rather than small broken lines

proprioception

perception of body position

proximity

elements that are close to one another tend to be grouped together

pupil

small opening in the iris through which light passes, can change in size

retina

light-sensitive lining at the back of the eye

rod

specialized photoreceptor that works well in low light conditions

Ruffini corpuscle

touch receptor deep in the skin that detects stretch

sensation

what happens when sensory information is detected by a sensory receptor and sent to the brain

sensorineural hearing loss

failure to transmit neural signals from the cochlea to the brain

sensory adaptation

failure to perceive stimuli that remain relatively constant over prolonged periods of time

signal detection theory

change in stimulus detection as a function of current mental state

similarity

elements that are alike tend to be grouped together

stapes

middle ear ossicle; also known as the stirrup

subliminal message

message presented below the threshold of conscious awareness

taste bud

structure that contains a group of taste receptor cells

temporal theory of pitch perception

auditory neurons codes for frequency by producing action potentials at the same frequency of the sound

thermoception

temperature perception

top-down processing

interpretation of sensations is influenced by available knowledge, experiences, and thoughts

trichromatic theory of color perception

color vision is mediated by the relative activity across the three groups of cones

tympanic membrane

eardrum

umami

fifth basis taste category – detects savory

vertigo

spinning sensation

vestibular sense

contributes to our ability to maintain balance and body posture

wavelength

length of a wave from one peak to the next