Chapter 6

Question 1

Sensation

Answer 1

The process in which specialized cells of the nervous system detect environmental stimuli and transducer their energy into receptor potentials

Question 2

Perception

Answer 2

The conscious experience and interpretation of information from the senses

Question 3

Hue

Answer 3

One of the perceptual dimensions of color; the dominant wavelength

Question 4

Brightness

Answer 4

One of the perceptual dimensions of color; intensity

Question 5

Saturation

Answer 5

One of the perceptual dimensions of color; purity

Question 6

Sensory receptor

Answer 6

A specialized neuron that detects a particular category of physical events

Question 7

Sensory transduction

Answer 7

The process by which sensory stimuli are transducer into slow graded receptor potentials

Question 8

Receptor potential

Answer 8

A slow graded electrical potential produced by a receptor cell in response to physical stimulus

Question 9

Retina

Answer 9

The neural tissue and photoreceptive cells located on the inner surface of the posterior portion of the eye

Question 10

Accommodation

Answer 10

Changes in the thickness of the lens of the eye accomplished by ciliary muscles that focus images of near or distant objects in the retina

Question 11

Rod

Answer 11

One of the receptor cells of the retina; sensitive to light of low intensity

Question 12

Coke

Answer 12

One of the receptor cells of the retina; maximally sensitive to one of three different wavelengths of light and hence encodes color vision

Question 13

Photoreceptors

Answer 13

One of the receptor cells of the retina; transducer photic energy into electrical potentials

Question 14

Fovea

Answer 14

The region of the retina that mediates the most acute vision of birds and higher mammals. Color sensitive cones constitute the only type of photo receptor found in the fovea

Question 15

Optic disk

Answer 15

The location of the exit point from the retina of the fibers of the ganglion cells that form the optic nerve; responsible
For blind spot

Question 16

Bipolar cell

Answer 16

A bipolar neuron located in the middle layer of the retina, converting information from the photoreceptors to the ganglion cells

Question 17

Ganglion cell

Answer 17

A neuron located in the retina that receives visual information from the bipolar cells; it axons gives rise to the optic nerve

Question 18

Horizontal cell

Answer 18

A neuron in the retina that interconnects adjacent photoreceptors and the outer processes of the bipolar cells

Question 19

Amacrine cell

Answer 19

A neuron in the retina that interconnects adjacent ganglion cells and the inner processes of the bipolar cells

Question 20

Photopigment

Answer 20

A protein dye bonded to retinal, a substance derived from vitamin A; responsible for transduction of visual information

Question 21

Lamella

Answer 21

A layer of membrane containing photopigments; found in rods and cones of the retina

Question 22

Olson

Answer 22

A class of protein that together with retinal constitutes the photopigments

Question 23

Retinal

Answer 23

A chemical synthesized from vitamin A; joins with an opsin to form photopigment

Question 24

Rhodopsin

Answer 24

A particular opsin found in rods

Question 25

Receptive field

Answer 25

That portion of the visual field in which the presentation of visual stimuli will produce and alteration in the firing rate of a particular neuron

Question 26

Vergence movement

Answer 26

The cooperative movement of the eyes which ensures that the image of an object falls on identical portions of both retinas

Question 27

Saccadic movement

Answer 27

The rapid jerky movement of the eyes used in scanning a visual scene

Question 28

Pursuit movement

Answer 28

The movement that the eyes make to maintain and image of a moving object on the fovea

Question 29

Optic nerve

Answer 29

Bundles of axons from retinal ganglion cells exit the eye and convert information to the lateral geniculate nucleus

Question 30

Dorsal lateral geniculate nucleus

Answer 30

A group of cell bodies within the lateral geniculate body of the thalamus; received input from the retina and projects to the primary visual cortex

Question 31

Optic chiasm

Answer 31

A cross shaped connection between the optic nerves located below the base of the brain just anterior to the pituitary gland

Question 32

Visual pathway

Answer 32

The pathway of visual processing from the retina to the lateral geniculate nucleus to striate and extrastriate virtual regions

Question 33

Striate cortex

Answer 33

Primary visual cortex

Question 34

Extrastriate cortex

Answer 34

A region of visual association cortex; receives fibers from the striate cortex and form the superior follicular and projects to the inferior temporal cortex

Question 35

Magnocellular layer

Answer 35

One of the inner two layers of neurons in the dorsal lateral geniculate nucleus; transmits information necessary for the perception of form, movement, depth, and small differences

Question 36

Parvocellular layer

Answer 36

One of the four outer layers of neurons in the dorsal lateral geniculate nucleus; transmits information necessary for perception of color and fine details to the primary visual cortex

Question 37

Koniocellular sublayers

Answer 37

One of the sublayers of neurons in the dorasal lateral geniculate nucleus found ventral to each of the magnocellular and parvocellular layers; transmits information from short wavelength cones to the primary visual cortex

Question 38

Dorsal stream

Answer 38

A system of interconnected regions of visual cortex involved in the perception of spatial location beginning with the striate cortex and ending with the posterior parietal cortex

Question 39

Ventral stream

Answer 39

A system of interconnecting regions of visual cortex involved in the perfectionist of form beginning with the striate cortex and ending with the inferior temporal cortex

Question 40

Protanopia

Answer 40

An inherited form of defective color vision in which red and green hues are confused; red cones are filled with green cone opsin

Question 41

Deuteranopia

Answer 41

An inherited form of defective color vision in which red and green hues are confused; green cones are filled with red cone opsin

Question 42

Tritanopia

Answer 42

An inherited form of defective color vision in which hues with short wavelengths are confused; blue cones are either lacking or faulty

Question 43

Negative afterimage

Answer 43

The imagine seen after a portion of the retina is exposed to an intense visual stimulus; consists of colors complementary to those of the physical stimulus

Question 44

Complementary colors

Answer 44

Colors that make white or gray when mixed together

Question 45

Cerebral achromatopsia

Answer 45

Inability to discriminate among different hues; caused by damage to the visual association cortex

Question 46

Visual agnosia

Answer 46

Deficits in visual perception in the absence of blindness; caused by brain damage

Question 47

Lateral occipital complex

Answer 47

A region of the extrastriate cortex, involved in perception of objects other than people’s bodies and faces

Question 48

Prosopagnosia

Answer 48

Failure to recognize particular people by the sight of their faces

Question 49

Fusiform face area

Answer 49

A region of the visual association cortex located in the inferior temporal lobe; involved in perception of faces and other simplex objects that require expertise to recognize

Question 50

Retinal disparity

Answer 50

The fact that points on objects located at different distances from the observer will fall on slightly different locations on the two retinas; provides the basis for stereopsis

Question 51

Posterior parietal cortex

Answer 51

The highest level of the dorsal stream of the visual association cortex; involved in perception of movement and spacial location

Question 52

Optic flow

Answer 52

The complex motion of points in the visual field caused by relative movement between the observer and environment; provides information about the relative distance of objects from the observer and of the relative direction of movement

Question 53

Akinetopsia

Answer 53

Inability to perceive movement cause by damage to area V5 of the visual association cortex