Chapter 4

Question 0

Proximal stimulus

Answer 0

The energies from the outside world that directly reach our sense organs

Question 1

Distal Stimulus

Answer 1

An object or event in the outside world

Question 2

Psychophysic

Answer 2

An approach to perception that relates the characteristics of physical stimuli to the sensory experiences they produce

Question 3

Absolute threshold

Answer 3

The smallest quantity of a stimulus that an individual can detect

Question 4

Difference threshold

Answer 4

The smallest amount that a given stimulus must be increased or decreased so that an individual can detect the difference

Question 5

Just-noticeable difference

Answer 5

The smallest difference that an organism can reliably detect between two stimuli

Question 6

Weber’s law

Answer 6

The observation that the size of the difference threshold is proportional to the intensity of the standard stimulus

Question 7

Fechner’s law

Answer 7

The observation that the strength of a sensation is proportional to the logarithm of physical stimulus intensity

Question 8

Perceptual sensitivity

Answer 8

An organism’s ability to detect a signal

Question 9

Decision criteria

Answer 9

An organisms rule for how much evidence it needs before responding

Question 10

Signal-detection theory

Answer 10

The theory that perceiving or not perceiving a stimulus is actually a judgment about whether a momentary sensory experience is due to background noise alone or to the background noise plus a signal

Question 11

Payoff matrix

Answer 11

Pattern of benefits and costs associated with certain types of responses

Question 12

Transduction

Answer 12

The process through which a physical stimulus is converted into a signal within the nervous system

Question 13

Sensory coding

Answer 13

The process through which the nervous system represents the qualities of the incoming stimulus —whether auditory or visual for example or whether a red light or a green one a sour taste or a sweet taste

Question 14

Specific theory

Answer 14

The proposal that different sensory qualities are signaled by different quality specific neurons. this theory is correct in only a few cases

Question 15

Pattern theory

Answer 15

The proposal that different sensory qualities are encoded by specific patterns of firing among the relevant neurons

Question 16

Sensory adaptation

Answer 16

The process by which the sensitivity to a stimulus declines if the stimulus is presented for an extended period of time

Question 17

Kinesthesis

Answer 17

The sensations generated by receptors in the muscles, tendons and joints that inform us of our skeletal movement

Question 18

Vestibular senses

Answer 18

This sensations generated by receptors in the semicircular canals of the inner ear that inform us about the heads orientation and movements

Question 19

Skin senses

Answer 19

The group of senses including pressure warm cold and pain through which we gain information about our immediate surroundings

Question 20

Nociceptors

Answer 20

Receptors in the skin they give rise to the sense of pain; they respond to various forms of tissue damage and to temperature extremes

Question 21

Gate control theory

Answer 21

The proposal that pain sensations must pass through a narrow gate in order to reach the brain and can be blocked at the gate by neurons that inhibit signals from the nociceptors

Question 22

Olfactory epithelium

Answer 22

A mucous membrane at the top of the nasal cavity; contains the olfactory receptor neurons that respond to airborne molecules called odorants

Question 23

Glomeruli

Answer 23

Sites in the brains olfactory bulb where signals from the smell receptors converge

Question 24

Pheromones

Answer 24

Biologically produced odorants that convey information to other members of the species

Question 25

Papillae

Answer 25

Structures on the tongue that contain the taste buds which in turn contain taste receptors

Question 26

Sound waves

Answer 26

Successive pressure variations in the air that vary in amplitude and wavelength

Question 27

Amplitude

Answer 27

The height of the Wavecrest used as a measure of sound intensity

Question 28

Frequency

Answer 28

The number of wave peaks per second. In sound, frequency governs the perceived pitch of the sound

Question 29

Cochlea

Answer 29

The coiled structure in the inner ear that contains the basilar membrane

Question 30

Eardrum

Answer 30

The taut membrane that transmit the vibrations caused by sound waves from the auditory canal to the ossicles in the middle ear

Question 31

Oval window

Answer 31

The membrane separating the middle ear from the inner ear

Question 32

Auditory ossicles

Answer 32

The three bones of the middle ear that transmit the vibrations of the eardrum to the oval window

Question 33

Basilar membrane

Answer 33

A membrane running the length of the cochlea; sound waves cause a deformation of this membrane bending the hair cells in the cochlea and thus stimulating the auditory receptors

Question 34

Hair cells

Answer 34

The auditory receptors in the cochlea, lodged between the basilar membrane and other membranes above

Question 35

Place theory

Answer 35

A proposal about pitch perception stating that regions of the basilar membrane respond to particular sound frequencies and the nervous system interprets the excitation from different basilar regions as different pitches

Question 36

Timbre

Answer 36

The quality of a sound apart from its pitch or loudness timbre enables us to distinguish a clarinet from an oboe or one persons voice from another

Question 37

Photoreceptor

Answer 37

A light-sensitive cell located on the retina that converts light energy into neural impulses

Question 38

Retinal image

Answer 38

The image of an object that is projected on the retina. its size increases with the size of that object and decreases with the objects distance from the eye

Question 39

Rods

Answer 39

Photoreceptors in the retina that respond to lower light intensities and give rise to achromatic (colorless) sensations

Question 40

Cons

Answer 40

Visual receptors that respond to greater light intensities and give rise to chromatic (color) sensations

Question 41

Fovea

Answer 41

The area roughly at the retinas center where cones are plentiful and visual acuity is greatest

Question 42

Optic nerve

Answer 42

The bundle of fibers that proceeds from each retina to the brain

Question 43

Photopigment

Answer 43

A chemical in the photoreceptors that changes its form in response to light producing an electrical change that signals to the nervous system that light is present

Question 44

Lateral inhibition

Answer 44

The pattern of interaction among neurons visual system in which activity in one neuron inhibits adjacent neurons responses

Question 45

Trichromatic color vision

Answer 45

The principle underlying human color. Color vision occurs to the operation of three sets of cones each maximally sensitive to a different wavelength of light

Question 46

Opponent-process theory

Answer 46

A theory of color vision that proposes three pairs of color antagonists: red-green, blue-yellow, and white-black. Excitation of neurons sensitive to one member of a pair automatically inhibits neurons sensitive to the other member

Question 47

Receptive field

Answer 47

For a particular sell individual system the pattern of retinal stimulation the most effectively causes the Cell to fire. For some cells this pattern is defined simply in terms of retinal location; for others the most effective input has a particular shape color or direction of motion

Question 48

Feature detectors

Answer 48

Neurons in the retina or brain that respond to specific attributes of the stimulus such as movement orientation and so on