AP Psychology Vocab Myers Unit 1 - Part D: Sensation- updated TEST Edit

Sensation

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

sensory receptors

Specialized cells unique to each sense organ that respond to a specific form of sensory stimulation.

selective attention

the focusing of conscious awareness on a particular stimulus

absolute threshold

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

difference threshold

the minimum difference between two stimuli required for detection 50% of the time - "just noticeable difference"

signal detection theory

a theory predicting how and when we detect the presence of a faint stimulus amid background stimulation. Assumes detection depends partly on a person's experience, expectations, motivation, and alertness

sensory adaptation

diminished sensitivity as a consequence of constant stimulation

transduction

the conversion of one form of energy into another. In sensation, the transforming of stimulus energy into a neural impulse.

Weber's law

the principle that, to be perceived as different, two stimuli must differ by a constant percentage

pupil

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

iris

a ring of muslce 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 processing of visual information

accomodation

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 well-lit conditions. The cones detect fine detail and give rise to color sensations

optic nerve

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

blind spot

the point at which the optic nerve leaves the eye, creating this because no receptor cells are located there

fovea

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

Young-Helmholtz Trichromatic theory

the theory that the retina contains three different color receptors (red, green, & blue) which when stimulated in combination, can produce the perception of any color

opponent-process theory

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