Mod 17 & 18

Question 1

sensation

Answer 1

the process by which our sensory reeptors receive and represent stimulus energies from our environment

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 brain’s 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

psychophysics

Answer 5

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

Question 6

absolute threshold

Answer 6

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

Question 7

signal detection theory

Answer 7

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 8

subliminal

Answer 8

below one’s absolute threshold for conscious awareness

Question 9

priming

Answer 9

the activation, often unconsciously, of certain associations, thus pre-disposing one’s perception, memory, or response

Question 10

difference threshold

Answer 10

the minimum difference between two stimuli required for detection fifty percent of the time. We experience the difference threshold as a just noticeable difference(ind)

Question 11

Weber’s law

Answer 11

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

Question 12

sensory adaptation

Answer 12

diminished sensitivity as a consequence of constant stimulation

Question 13

transduction

Answer 13

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 brains can interpret

Question 14

wavelength

Answer 14

the distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission

Question 15

hue

Answer 15

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 16

intensity

Answer 16

the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave’s amplitude

Question 17

pupil

Answer 17

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

Question 18

iris

Answer 18

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 19

lens

Answer 19

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

Question 20

retina

Answer 20

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 21

accommodation

Answer 21

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

Question 22

rods

Answer 22

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

Question 23

cones

Answer 23

retinal recpetor cells that are concentrated near the cneter of the retina and that function in daylight or in well lit conditions. the cones detect fine detail and give rise to color sensations

Question 24

optic nerve

Answer 24

the nerve that carries neural impulses from eh eye to brain

Question 25

blind spot

Answer 25

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

Question 26

fovea

Answer 26

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

Question 27

feature detectors

Answer 27

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

Question 28

parallel processing

Answer 28

the processing of many aspects of a problem simultaneously’ the brain’s natural mode of information processing for many functions, including vision. Contrasts with the step by step-serial processing of most computers and f conscious problem solving

Question 29

Young Helmholtz trichromatic(three color) theory

Answer 29

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

Question 30

opponent-process theory

Answer 30

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