Vision

Question 1

Retina

Answer 1

where photoreceptors transform light into a neural signal (transduction)

Question 2

Ganglion Cells

Answer 2

gather information from photoreceptors
*responsible for the opponent process, which occurs AFTER the trichromatic color scale

Question 3

Photoreceptors

Answer 3

rods and cones

Question 4

Cones

Answer 4

-located in the center of the retina
-low sensitivity to dim light, high color sensitivity, high detail sensitivity

Question 5

Rods

Answer 5

-located in the periphery
-high sensitivity to dim light, low color sensitivity, low detail sensitivity

Question 6

Fovea

Answer 6

the center of the retina

Question 7

Do we have more rods or cones in the eye?

Answer 7

Rods

Question 8

Why can’t nearsighted people see far away?

Answer 8

light reflected from an object is focused in front of the retina

Question 9

Why can’t far sighted people see up close?

Answer 9

their point of focus fall beyond the surface of the retina

Question 10

Trichromatic Color Theory

Answer 10

there are 3 different cones each sensitive to wavelengths of light (short, medium, and long wavelengths)
*phototransuction, level of cones
*short: blue
*medium: green
*long: red

Question 11

How are color blindness and cones related?

Answer 11

Those who are color blind have a deficiency on one or more of the cones

Question 12

Opponent process theory

Answer 12

we perceive color in terms of opposing pairs: red/green, yellow/blue, black/white

Question 13

How do photoreceptors travel through the brain?

Answer 13

the signal travels down the optic nerve to the brain and passes through the thalamus and is sent to the primary visual cortex

Question 14

What happens after neurons are sent to the visual cortex?

Answer 14

information is routed to other cortical areas for processing (these are the dorsal and ventral pathways)

Question 15

Dorsal Pathway

Answer 15

“where pathway”- visually guided movements
*e.g. putting an envelope in the mail

Question 16

Ventral Pathway

Answer 16

“what pathway” - object identification, identifying who a person is

Question 17

Visual agnosia

Answer 17

inability to recognize objects

Question 18

Prosopagnosia

Answer 18

inability to recognize faces

Question 19

Monocular depth cues

Answer 19

help us perceive depth using one eye

Question 20

Monocular depth cues examples

Answer 20

relative height, relative size, linear perspective, light & shadow, interposition (things in front cover up what’s behind)

Question 21

Binocular depth cues

Answer 21

help us perceive depth using both eyes

Question 22

Retinal disparity

Answer 22

different retinal images each eye receives based on its different perspectives

Question 23

Convergence

Answer 23

when a person views a nearby object, the eye muscles turn the eyes inward

Question 24

How do we keep our perception of an object constant despite different input?

Answer 24

-size constancy
-brightness constancy

Question 25

Size constancy

Answer 25

we understand that objects appear smaller when further away

Question 26

Brightness constancy

Answer 26

we understand that shadow/darkness affects color

Question 27

Feature detectors

Answer 27

cells that respond selectively to specific features
*respond to lines, angles, and corners in particular orientations on the retina
*this is bottom-up processing
*first discovered by Hubel and Weisel in cat study