Senses and Perception

sensation

detect physical energy from the environment and encode as neural signals

sensory receptors

sensory nerve endings in your nose, eyes, ears, and other sensory organ

perception

process that organizes and interprets sensory info and makes it meaningful

prosopagnosia

face blindness

Phonagnosia

voice blindness

bottom-up processing

analysis that begins with the sensory receptors and works up to the brain's integration of sensory information

top-down processing

the use of preexisting knowledge, experience, expectations to organize and construct perceptions

selective attention

the ability to focus on only one stimulus from among all sensory input

cocktail party effect

ability to attend to only one voice among many

inattentional blindness

failure to detect stimuli that are in plain sight when our attention is focused elsewhere

change blindness

failing to notice changes in the environment; a form of inattentional blindness

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 brains can interpret.

absolute threshold

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

signal detection theory

a theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness.

subliminal

below the threshold of conscious perception

Priming

An enhanced ability to think of a stimulus, such as a word or object, as a result of a recent exposure to the stimulus

difference threshold

the minimum difference between two stimuli required for detection 50 percent of the time

Weber's Law

the just noticeable difference of a stimulus is a constant proportion despite variations in intensity

sensory adaptation

tendency of sensory receptor cells to become less responsive to a stimulus that is unchanging

perceptual set

a predisposition or readiness to perceive something in a particular way

Wavelength

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

short wavelength, high frequency

bluish colors

long wavelength, low frequency

reddish colors

light wave with great amplitude

bright colors

light wave with small amplitude

dull colors

hue

a particular shade of a given color

cornea

the transparent outer covering of the eye

pupil

The opening through which light enters the eye

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

accomodation of lens

lenses change shape to focus on objects near or far

myopia

nearsightedness

hyperopia

farsightedness

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