Vision

Question 1

wavelength is to intensity as

Answer 1

colour is to brightness

Question 2

depth of focus can be increased by

Answer 2

constricting the pupils

Question 3

What is an important depth-perception cue?

Answer 3

binocular disparity

Question 4

Where are the visual receptors?

Answer 4

the last layer of the retina to be reached by the light entering the eye

Question 5

What can be found on the blind spot?

Answer 5

the axons of retinal ganglion cells

Question 6

Because of optic disks we have?

Answer 6

a blind spot in the visual field of each eye

Question 7

Colour is mediated by

Answer 7

photopic system

Question 8

what is the Purjunkie Effect?

Answer 8

lights in the green-blue portion of the spectrum are brighter than equally intense lights in the yellow-red portion of the spectrum when viewed under dim illumination

Question 9

What are eye movements called?

Answer 9

Saccades

Question 10

Primary visual cortex neurons are

Answer 10

grouped in functional vertical columns

Question 11

what is binocular disparity?

Answer 11

the difference in the position of the same image on the two retinas; greater for closer objects

Question 12

what are stellate cells?

Answer 12

small star shaped interneurons

Question 13

what is a blind spot?

Answer 13

for the bundle of retinal ganglion cells axons to leave the eye there must be a gap in the receptor layer

Question 14

What is the fovea?

Answer 14

an indentation at the centre of the retina that is specialised for high acuity vision

Question 15

what is the fovea specialised for?

Answer 15

high acuity vision

Question 16

what is a spectral sensitivity curve?

Answer 16

a graph of the relative brightness of the same intensity at different wavelengths

Question 17

what is a photopic spectral sensitivity curve?

Answer 17

judge the relative brightness of differenet wavelengths shone at the fovea

Question 18

what is the scotopic spectral sensitivity curve?

Answer 18

judge relative brightness of different wavelengths shone on the peripheral area of the retina at an intensity too low for cones to detect

Question 19

Why doesn’t the world disappear when we blink?

Answer 19

temporal integration

Question 20

what are mach bands?

Answer 20

they enhance the contract at each edge and make the edge easier to see

Question 21

what are simple cells?

Answer 21

cells that have receptor fields that can be divided into on and off regions

Question 22

What is the component theory?

Answer 22

colour has three different kinds of receptors

Question 23

what is the opponent processing theory?

Answer 23

two different classes of cells for encoding colour and another for brightness

Question 24

What is Hemiaopsic?

Answer 24

having scotoma covering half of the visual field

Question 25

what is a scotoma?

Answer 25

an area of blindness in the corresponding area of the contralateral visual field.

Question 26

what is the order of the retinal geniculate striate system?

Answer 26

retinal ganglion cells, lateral geniculate neurons, striate neurons

Question 27

What is a rhodspin?

Answer 27

a red pigment extracted from a rod

Question 28

what happens when a rod is in the darkness?

Answer 28

their sodium channels partially open causing the rod to be partiall depolarized

Question 29

What happens in scotopic vision?

Answer 29

lack of colour, dim light, low acuity. ,pore sensitive

Question 30

how many rods are there on one ganglion cell?

Answer 30

100

Question 31

Are there any rods in the fovea?

Answer 31

no

Question 32

what does photopic vision mediate?

Answer 32

in good lighting, high acuity and colour

Question 33

A few cones converge onto how many ganglion cells?

Answer 33

on ganglion cell

Question 34

what are bipolar and amacrine cells specialised for?

Answer 34

lateral communication

Question 35

Complex cells are?

Answer 35

binocular, rectangular and unresponsive to diffuse light.

Question 36

what is the parvocellular level?

Answer 36

a communication channel responsive to colour

Question 37

what is the magnocellular level

Answer 37

a communication channel responsive to movement and rods

Question 38

What are on centre cells in comparison to off centre cells?

Answer 38

they respond to light shone at the central region of their receptive cells with on firing and off firing if light is shone at the periphery whereas off centre cells respond to light shone at the periphery of their receptive cells with on firing and on the centre with off firing.