chapter 6: sensation and perception

Question 1

sensation

Answer 1

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. (p. 230)

Question 2

perception

Answer 2

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

Question 3

bottom-up processing

Answer 3

analysis that begins with the sensory receptors and works up to the brains integration of sensory information

Question 4

top-down processing

Answer 4

information processing guided by higher level mental processes, as when we construct perceptions drawing on our experience and expectations

Question 5

transduction

Answer 5

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 brain can interpret.

Question 6

psychophysics

Answer 6

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

Question 7

absolute threshold

Answer 7

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

Question 8

signal detection theory

Answer 8

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.

Question 9

subliminal

Answer 9

below ones absolute threshold for conscious awareness

Question 10

priming

Answer 10

the activation, often unconsciously, of certain associations, thus predisposing ones perception, memory, or response.

Question 11

sensory adaptation

Answer 11

diminished sensitivity as a consequence of constant stimulation. When we are constantly exposed to an unchanging stimulus, we become less aware of it because our nerve cells fire less frequently. (To experience sensory adaptation, move your watch up your wrist an inch: You will feel it—but only for a few moments.)

Question 12

perceptual set

Answer 12

a mental predisposition to perceive one thing and not another.
a set of mental tendencies and assumptions that affects (top-down) what we hear, taste, feel and see
looking at hidden image drawings- what we see in such a drawing can be influenced by first looking at either of the two unambiguous versions

Question 13

what determines our perceptual set?

Answer 13

Through experience we form concepts, or schemas, that organize and interpret unfamiliar information. Our preexisting schemas for monsters and tree trunks influence how we apply top-down processing to interpret ambiguous sensations.

Question 14

ways emotions can influence perception

Answer 14

walking destinations look farther away to those who have been fatigued by prior exercise.
a hill looks steeper to those who are wearing a heavy backpack or have just been exposed to sad, heavy classical music rather than light, bouncy music. As with so many of life’s challenges, a hill also seems less steep to those with a friend beside them.
a target seems farther away to those throwing a heavy rather than a light object at it.
even a softball appears bigger when you are hitting well, observed Jessica Witt and Proffitt (2005), after asking players to choose a circle the size of the ball they had just hit well or poorly. (There’s also a reciprocal phenomenon: Seeing a target as bigger—as happens when athletes focus directly on a target—improves performance [Witt et al., 2012].)

Question 15

motives also affect perception

Answer 15

ex: Desired objects, such as a water bottle when thirsty, seem closer (Balcetis & Dunning, 2010). This perceptual bias energizes our going for it

Question 16

wavelength

Answer 16

the distance from one wave peak to the next which determines hue

Question 17

hue

Answer 17

the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, etc

Question 18

intensity

Answer 18

the amount of energy in a light wave or sound wave, which influences what we percieve as brightness or loudness. intensity is determined by a waves amplitude(height)

Question 19

pupil

Answer 19

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

Question 20

iris

Answer 20

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 21

lens

Answer 21

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

Question 22

retina

Answer 22

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 23

accommodation

Answer 23

1. in developmental psychology, adapting our current understandings (schemas) to incorporate new information. 2. in sensation and perception, the process by which the eyes lens changes shape to focus near or far objects on the retina

Question 24

how the retina sees an image

Answer 24

The retina doesn’t “see” a whole image. Rather, its millions of receptor cells convert particles of light energy into neural impulses and forward those to the brain. There, the impulses are reassembled into a perceived, upright-seeming image. And along the way, visual information processing percolates through progressively more abstract levels. All this happens with astonishing speed. As a baseball pitcher’s fastball approaches home plate, the light signals work their way from the batter’s retina to the visual cortex, which then informs the motor cortex, which then sends out orders to contract the muscles—all in the 4/10ths of a second that the ball is in flight.

Question 25

young-Hemholtz trichromatic (three-color) theory

Answer 25

the theory that the retina contains three different color receptors—one most sensitive to red, one to green, one to blue—which, when stimulated in combination, can produce the perception of any color. (p. 243)

Question 26

color-deficient vision

Answer 26

people who lack functioning red-or green-sensitive cones, or sometimes both. their vision is monochromatic(one-color) or dichromatic(two-color) instead of trichromatic, making it impossible to distinguish red and green.

Question 27

afterimage effect

Answer 27

after staring at certain colors for a while(tiring your neural responses to them) you look at something absent of color(white) and see the opponent colors from the original image

Question 28

opponent-process theory

Answer 28

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

Question 29

feature detectors

Answer 29

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