Chapter 3

Question 1

The smallest spatial detail that can be resolved at 100% contrast.

Answer 1

acuity

Question 2

A reduction in response caused by prior or continuing stimulation.

Answer 2

adaptation

Question 3

A developmental disorder characterized by reduced spatial vision in an otherwise healthy eye, even with proper correction for refractive error. Also known as lazy eye.

Answer 3

amblyopia

Question 4

A condition in which the two eyes have different refractive errors (e.g., one eye is farsighted and the other not).

Answer 4

anisometropia

Question 5

A vertical arrangement of neurons, which tend to have similar receptive fields and similar orientation preferences.

Answer 5

column

Question 6

A cortical neuron whose receptive field does not have clearly defined excitatory and inhibitory regions.

Answer 6

complex cell

Question 7

Referring to the opposite side of the body (or brain).

Answer 7

contralateral

Question 8

A function describing how the sensitivity to contrast (defined as the reciprocal of the contrast threshold) depends on the spatial frequency (size) of the stimulus.

Answer 8

contrast sensitivity function (CSF)

Question 9

The smallest amount of contrast required to detect a pattern.

Answer 9

contrast threshold

Question 10

The difference in luminance between an object and the background, or between lighter and darker parts of the same object.

Answer 10

contrast

Question 11

The amount of cortical area (usually specified in millimeters) devoted to a specific region (e.g., 1 degree) in the visual field.

Answer 11

cortical magnification

Question 12

A phase in the life span during which abnormal early experience can alter normal neuronal development. Proposed for the development of binocular vision and development of a first human language.

Answer 12

critical period

Question 13

For a grating, a pair consisting of one dark bar and one bright bar.

Answer 13

cycle

Question 14

The number of pairs of dark and bright bars (cycles of a grating) per degree of visual angle.

Answer 14

cycles per degree

Question 15

The process by which a cell in the cortex first increases its firing rate as the bar length increases to fill up its receptive field, and then decreases its firing rate as the bar is lengthened further.

Answer 15

end stopping

Question 16

An acoustic, electrical, electronic, or optic device, instrument, computer program, or neuron that allows the passage of some range of parameters (e.g., orientations, frequencies) and blocks the passage of others.

Answer 16

filter

Question 17

A 1-millimeter block of striate cortex containing two sets of columns, each covering every possible orientation (0–180 degrees), with one set preferring input from the left eye and one set preferring input from the right eye.

Answer 17

hypercolumn

Question 18

Referring to the same side of the body (or brain).

Answer 18

ipsilateral

Question 19

A neuron located between the magnocellular and parvocellular layers of the lateral geniculate nucleus. (From the Greek for “dust” referring to the appearance of the cells.)

Answer 19

koniocellular cell

Question 20

A structure in the thalamus, part of the midbrain, that receives input from the retinal ganglion cells and has input and output connections to the visual cortex.

Answer 20

lateral geniculate nucleus (LGN)

Question 21

Either of the bottom two neuron-containing layers of the lateral geniculate nucleus, the cells of which are physically larger than those in the top four layers.

Answer 21

magnocellular layer

Question 22

The property of the receptive fields of striate cortex neurons by which they demonstrate a preference, responding somewhat more rapidly when a stimulus is presented in one eye than when it is presented in the other.

Answer 22

ocular dominance

Question 23

The tendency of neurons in striate cortex to respond optimally to certain orientations and less to others.

Answer 23

orientation tuning

Question 24

Any of the top four neuron-containing layers of the lateral geniculate nucleus, the cells of which are physically smaller than those in the bottom two layers.

Answer 24

parvocellular layer

Question 25

The relative position of a grating.

Answer 25

phase

Question 26

The area of the cerebral cortex of the brain that receives direct inputs from the lateral geniculate nucleus, as well as feedback from other brain areas.

Answer 26

primary visual cortex (V1), area 17, or striate cortex

Question 27

A cortical neuron whose receptive field has clearly defined excitatory and inhibitory regions.

Answer 27

simple cell

Question 28

A grating with a sinusoidal luminance profile as shown in Figure 3.4b.

Answer 28

sine wave grating

Question 29

The number of cycles of a grating (e.g., dark and bright bars) per unit of visual angle (usually specified in cycles per degree).

Answer 29

spatial frequency

Question 30

A pattern analyzer, implemented by an ensemble of cortical neurons, in which each set of neurons is tuned to a limited range of spatial frequencies.

Answer 30

spatial-frequency channel

Question 31

A misalignment of the two eyes such that a single object in space is imaged on the fovea of one eye and on a nonfoveal area of the other (turned) eye.

Answer 31

strabismus

Question 32

The perceptual illusion of tilt, produced by adaptation to a pattern of a given orientation.

Answer 32

tilt afteraffect

Question 33

The orderly mapping of the world in the lateral geniculate nucleus and the visual cortex.

Answer 33

topographical mapping

Question 34

The angle subtended by an object at the retina.

Answer 34

visual angle

Question 35

The deleterious effect of clutter on peripheral object recognition.

Answer 35

visual crowding