chapter 3-spatial visoin: from spots to stripes Flashcards Preview

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Flashcards in chapter 3-spatial visoin: from spots to stripes Deck (38):
1

initial processing occurs in the

retina

2

thalamus

sensory stop over

3

LGN

visual processing

4

pathway

ganglion cells send AP to LGN which go onto primary visual cortex (V1)

5

spatial frequency

affected by number of stripes, in relation to viewing distance, width of stripes in viewing angle

6

more of the retina ___ spatial frequency

lower

7

less of the retina ___ spatial frequency

higher

8

contrast

affect how visible

9

phase position

alignment with receptive field, position

10

orientation

angle of the grating. vertical, horizontal

11

contrast sensitivity function

visibility of a pattern as a function of spatial frequency and contrast

12

what spatial frequencies are best

mid

13

visibility drops off faster with age for ___ spatial frequency than ___ spatial frequencry

high, low

14

photoreceptors and stripes

light falls on photoreceptors, represent grating

15

band pass graph

receptive fields, middle is best

16

low pass

lowest is visible

17

high pass

highest is visible

18

retinal ganglion cells

response of a ganglion cell to gratings of different frequencies

19

how ___ lines up in receptive field predicts response strength

light

20

phase

phase of a grating relates to its position within a receptive field

21

ganglion cells respond best when

spatial frequency aligned with receptive fields

22

neurons with small receptive fields responds to ___ spatial frequencies

high

23

neurons with large receptive fields respond to ___ spatial frequencies

low

24

receptive field of ganglion cells

circular

25

receptive field of LGN

mostly circular

26

v1 and above

mostly elongated

27

visual resolution declines in an orderly fashion with distance from

fovea

28

parvocellular layer of LGN

small cell bodies, p gang cell; small receptive field, good for form/detail, high spatial resolution

29

magnocellular layer of LGN

large cell bodies, m gang cells; large receptive field, good for motion/temporal resolution

30

topographical mapping

orderly positions of projections, retinotopic mapping, position on the retina

31

strabismus

misalignement of the two eyes, treatable with eye patch or surgery

32

receptive fields in striate cortex respond best to

bars of light

33

simple cells

respond to bar of light or dark, RF phase sensitive; clearly defined inhibitory and excitatory receptive fields

34

complex cells

some cells respond to both bars of light and dark, phase insensitive; no clearly defined inhibitory and excitatory fields; not phase sensitive

35

orientation tuning

tendency of neurons in striate cortex to respond most to bars of certain orientation; response rate falls off with angular difference

36

adaptation

reduction in response caused by prior or continuing stimulation; brain adapts to stimulus and responds less

37

tilt aftereffect

the perceptual illusion of tilt, produced by adapting to a pattern of a given orientation

38

tilt aftereffect supports what idea

that visual system contains individual neurons selective for different orientations