Unit 4: Sensation/Perception

Question 1

Absolute threshold

Answer 1

The minimum stimulation needed to detect particular stimulus 50 percent if the time

Question 2

Retina

Answer 2

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

Question 3

Cones

Answer 3

Retinal receptors 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 ride to color sensations

Question 4

Difference threshold

Answer 4

The minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference

Question 5

Perception

Answer 5

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

Question 6

Rods

Answer 6

Retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when comes don’t respond

Question 7

Opponent-process theory

Answer 7

The theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. For example, some cells are stimulate by green and inhibited by red; others are stimulated by red and inhibited by green

Question 8

Fovea

Answer 8

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

Question 9

Cochlea

Answer 9

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

Question 10

Perceptual constancy

Answer 10

Perceiving objects as unchanging (having consistent shapes, size, brightness and color) even as illumination and retinal images change

Question 11

Monocular cues

Answer 11

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

Question 12

Transduction

Answer 12

Conversion of one form of energy into another. Ex: sights, sounds, and smell change into neural impulses our brain can interpret

Question 13

Weber’s law

Answer 13

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

Question 14

Binocular cues

Answer 14

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

Question 15

Place theory

Answer 15

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

Question 16

Retinal disparity

Answer 16

A binocular cue for perceiving depth: by comparing images from the retinas in the two eyes, the brain computes distance-the grater the disparity (difference) between the two images, the closer the object

Question 17

Pitch

Answer 17

A tone’s experienced highness or lowness; depends on frequency

Question 18

Bottom-up processing

Answer 18

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

Question 19

Feature detectors

Answer 19

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

Question 20

Gate-control theory

Answer 20

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 signaled traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain

Question 21

Psychophysics

Answer 21

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

Question 22

Sensory adaptation

Answer 22

Diminished sensitivity as a consequence of constant stimulation

Question 23

Signal detection theory

Answer 23

A theory prediction 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, motivations, and alertness

Question 24

Top-down processing

Answer 24

Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experiences and expectations.

Question 25

Accommodation (perceptual)

Answer 25

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

Question 26

Frequency theory

Answer 26

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

Question 27

Habituation

Answer 27

Decreasing responsiveness with repeated stimulation. As infants gain familiarity with repeated exposure to a visual stimulus, their wanes and they look away sooner

Question 28

Lens

Answer 28

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

Question 29

Optic nerve

Answer 29

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

Question 30

Pupil

Answer 30

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

Question 31

Vestibular sense

Answer 31

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

Question 32

Blind spot

Answer 32

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

Question 33

Iris

Answer 33

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

Question 34

Hue

Answer 34

The dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth

Question 35

Sensation

Answer 35

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

Question 36

Subliminal

Answer 36

Below one’s absolute threshold for conscious awareness