Chapter 4: Sensing & Perceiving Our World Key Terms

Question 1

Sensation:

Answer 1

A physical process involving the stimulation of our sense organs by features of the outer world.

Question 2

Perception:

Answer 2

A psychological process involving the act of organizing and INTERPRETING sensory experience.

Question 3

Sensory adaptation:

Answer 3

The process by which our sensitivity diminishes when an object constantly stimulates our senses.

Question 4

Transduction:

Answer 4

The conversion of physical into neural information.

Example: cells in the retina change light waves to neural energy.

Question 5

Absolute threshold:

Answer 5

The lowest intensity level of a stimulus a person can detect 50% of the time.

Question 6

Signal detection theory:

Answer 6

The viewpoint that both stimulus intensity and decision-making processes are involved in the detection of a stimulus.

Question 7

Difference threshold:

Answer 7

The smallest amount of change between two stimuli that a person can detect half of the time.

Question 8

Just noticeable difference (JNS):

Answer 8

The difference threshold that is the smallest change in a stimulus that can be perceived most of the time, another name for difference threshold.

Question 9

Weber’s law:

Answer 9

The finding that the size of a JND is a constant fraction of the intensity of the stimulus.

Question 10

Cornea:

Answer 10

The clear, hard covering that protects the lens of the eye.

Question 11

Pupil:

Answer 11

The opening in the iris through which light enters the eye.

Question 12

Iris:

Answer 12

The muscle that forms the colored part of the eye; it adjusts the pupil to regulate the amount of light that enters the eye.

Question 13

Lens:

Answer 13

The structure that sits behind the pupil; it bends the light rays that enter the eye to focus images on the retina.

Question 14

Accommodation:

Answer 14

The process by which the muscles control the shape of the lens to adjust to viewing objects at different distances.

Question 15

Retina:

Answer 15

The thin layer of nerve tissue that lines the back of the eye.

Question 16

Photoreceptors:

Answer 16

Cells in the retina (called rods and cones) that convert light energy into nerve energy.

Question 17

Rods:

Answer 17

Photoreceptors that function in low illumination and play a key role in night vision; responsive to dark-and-light contrast.

Question 18

Dark adaptation:

Answer 18

The process of adjustment to seeing in the dark.

Question 19

Cones:

Answer 19

Photoreceptors that are responsible for color vision and are most functional in conditions of bright light.

Question 20

Fovea:

Answer 20

A spot on the back of the retina that contains the highest concentration of cones in the retina; place of clearest vision.

Question 21

Visual acuity:

Answer 21

The ability to see clearly.

Question 22

Optic nerve:

Answer 22

The structure composed of the axons of ganglion cells from the retina that carry visual information from the eye to the brain.

Question 23

Blind spot:

Answer 23

The point at which the optic nerve exits the eye; has no receptor cells and therefore nothing is seen.

Question 24

Optic chiasm:

Answer 24

The point at which strands of the optic nerve from half of each eye cross over to the opposite side of the brain.

Question 25

Feature detectors:

Answer 25

Neurons in the visual cortex that analyze the retinal image and respond to specific aspects of shapes, such as angles and movements.

Question 26

Fusiform face area:

Answer 26

A region in the temporal lobe that primarily responds to and recognizes faces.

Question 27

Trichromatic color theory:

Answer 27

The theory that all color that we experience results from a mixing of three colors of light (red, green, and blue).

Question 28

Opponent-process theory:

Answer 28

The theory that color vision results from cones linked together in three pairs of opposing colors (blue/yellow, red/green, and black/white), so that activation of one member of the pair inhibits activity in the other.

Question 29

Depth perception:

Answer 29

The ability to see things in three dimensions and to discriminate what is near from what is far.

Dependent on binocular and monocular depth cues

Question 30

Binocular depth cues:

Answer 30

Aids to depth perception that rely on input from BOTH eyes.

Question 31

Binocular disparity:

Answer 31

The difference in retinal images due to the fact that our two eyes are separated by a few inches; this factor is an important cue in depth perception.

Question 32

Monocular depth cues:

Answer 32

Aids to depth perception that do NOT require two eyes.

Question 33

Perceptual consistency:

Answer 33

The ability of the brain to preserve perception of objects in spite of changes in retinal image when an object changes in position or distance from the viewer.

Question 34

Similarity:

Answer 34

A Gestalt law that says we tend to group like objects together in visual perception.

Question 35

Continuity:

Answer 35

The Gestalt law that says we see points or lines in such a way that they follow a continuous path.

Question 36

Proximity:

Answer 36

A Gestalt law that says we tend to group objects together that are near one another.

Question 37

Law of closure:

Answer 37

The tendency to perceive a whole object in the absence of complete information.

Question 38

Figure:

Answer 38

A specific object in front of an unformed background.

Question 39

Ground:

Answer 39

The background behind objects or figures.

Question 40

Timbre:

Answer 40

Is the quality or “color” of a particular sound and is a result of the sound’s complexity or number of sound frequencies.

Question 41

Tympanic membrane:

Answer 41

The eardrum.

Question 42

Semicircular canals:

Answer 42

A structure of the inner ear involved in maintaining balance.

Question 43

Cochlea:

Answer 43

A bony tube of the inner ear, which is curled like a snail’s shell and filled with fluid.

Question 44

Basilar membrane:

Answer 44

A membrane that runs through the cochlea; contains the hair cells.

Question 45

Hair cells:

Answer 45

Inner ear sensory receptors for sound that transduce sound vibrations into neural impulses.

Question 46

Auditory nerve:

Answer 46

The nerve that receives action potentials from the hair cells and transmits auditory information to the brain.

Question 47

Bodily senses:

Answer 47

The senses based in the skin, the body, or any membrane surfaces.

Touch, temperature, pain, position/motion, balance, and interoception (perception of bodily senses)

Question 48

Mechanoreceptors:

Answer 48

Receptor cells in the skin that are sensitive to different tactile qualities, such as shape, grooves, vibrations, and movements.

Question 49

Pain:

Answer 49

A complex emotional and sensory experience associated with actual or potential tissue damage.

Question 50

Phantom limb pain:

Answer 50

Occurs when a person who has lost an arm or leg continues to feel pain in the lost limb.

Question 51

Nociceptive pain:

Answer 51

Pain from skin and/or tissue damage or injury.

Heat, cold, chemical irritation, and pressure.

Question 52

Gate control theory of pain:

Answer 52

The idea that the SPINAL CORD regulates the experience of pain by the BALANCING OF SIGNALS to the brain from small pain nerve fibers and larger non-pain fibers. The pain “gate” opens when more pain signals are sent to the brain than non-pain signals. Pain is blocked when the reverse happens.

Question 53

Olfactory sensory neurons:

Answer 53

The sensory receptors for smell that reside high up inside the nose.

Question 54

Olfactory bulb:

Answer 54

A FOREBRAIN structure that sends information either directly to the smell-processing areas in the cortex or indirectly to the cortex by way of the thalamus.

Question 55

Papillae:

Answer 55

Textured structures on the surface of the tongue; contain thousands of taste buds.

Question 56

Taste buds:

Answer 56

Structures inside the papillae of the tongue that contain the taste receptor cells.

Question 57

Taste receptor cells:

Answer 57

Sensory receptors for taste that reside in the taste buds.

Question 58

Gustatory cortex:

Answer 58

The cortical region of the brain located in the insula area of the frontal lobe where taste sensations are processed and interpreted.

Question 59

Synesthesia:

Answer 59

An unusual sensory experience in which a person experiences sensations in one sense when a different sense is stimulated.

Question 60

Afterimages:

Answer 60

Visual images that remain after removal of or looking away from the stimulus.