vision 2

Question 1

complex cells receptive fields

Answer 1

Complex cells have receptive fields like simple cells, with one big exception: they abstract for position.

Question 2

Simple cells are

Answer 2

cortical cells which respond to more complex stimuli and receptor fields than ganglion cells.

Question 3

Simple cells receptive fields

Answer 3

1. Their receptive fields are created from converging LGN neurons with center-surround receptive fields.
2. This creates a receptive field shape that is a straight line, and the orientation of the line is crucial.
3. This is an example of hierarchical processing

Question 4

hierarchical processing:

Answer 4

several cells with similar but spatially offset receptive fields converge on a higher order cell to create an altogether new type of receptive field.

Question 5

While simple cells require a ______;

complex cells require _______.

Answer 5

line or edge at a particular position in the visual field,

are not so finicky about position. The line or edge can be anywhere within the receptive field, and these cells especially like to see lines or edges moving across the field.

Question 6

Major inputs are a convergence of several simple cells whose positions are slightly offset. The converging simple cells make:

Answer 6

excitatory synapses on the complex cell, and any single simple cell can cause the complex cell to fire

Question 7

Visual processing at the cortical level is initiated in ____

Answer 7

V1, the primary visual area.

Question 8

V1 is functionally specialized to ____

Answer 8

analyze

1. orientation
2. ocular dominance
3. color information from specific retinal locations.

Question 9

The cells in V1 are organized in ___

Answer 9

an array of hypercolumns, each of which corresponds to a point on the retina.

Question 10

Each column in the hypercolumn responds to

Answer 10

a particular orientation;

adjacent columns manage information from adjacent retinal locations.

Question 11

Hypercolumns are 1 mm on a side and receives information from about _____.

Answer 11

10,000 LGN axons

Question 12

Color information, which is separated out from spatial information in the ____, is handled in _____

Answer 12

retina

central regions of the hyercolumns called blobs.

Question 13

The orientations of lines in the visual field lie in _____.

Answer 13

different rays of pinwheels that radiate from the central blobs.

All cells in a vertical column are sensitive to the same orientation.

Question 14

Of the many different types of cells in V1, _____ are most important to the perception of color.

Answer 14

blobs and interblobs

Question 15

blobs and interblobs receive input from:

Answer 15

the parvo cells of the LGN

Question 16

blobs and interblob function

Answer 16

continue the processing of color information

Question 17

Sensitive period (or critical period):

Answer 17

period of time when connections can be altered by visual experience.

Question 18

For humans, the critical period is

Answer 18

the first 2 -3 years

Question 19

connections of critical period

Answer 19

while genetically determined, are not immutable, at least for a while after birth.

Question 20

Indicate the conditions under which the effects of abnormal developmental experiences can be reversed.

Answer 20

If the abnormal development is detected and treated within the sensitive period, the effects of abnormal development up until that point can be reversed.

Question 21

example of conditions under which the effects of abnormal developmental experiences can be reversed.

Answer 21

Infants born with congenital strabismus or cataracts can end up with relatively normal vision, provided these defects are detected and repaired soon after birth.

However, the longer you wait, the greater the visual deficit will be. If not repaired by 2 years of age, there will be substantial permanent visual deficits