15. Sensation & Perception: Motion perception

Question 1

what are the func of motion perception? (6)

Answer 1

1. help break camouflage
2. help attract attention
3. help segregate objects from the background
4. help us interpret events
5. help us determine the structure of objects
6. help s determine what actions ppl are performing

Question 2

how does motion perception help break camo?

Answer 2

camouflaged animal can be invisible UNTIL it moves

Question 3

how does motion perception help attract attention?

Answer 3

movement attracts attention, breaks camo

Question 4

how does motion perception help segregate objects?

Answer 4

motion attracts attention, helping us segregate objects from the background

Question 5

how does motion perception help us interpret events?

Answer 5

• seeing how objects INTERACT, allows us to infer CAUSALITY, R/S & SOCIAL R/S

Question 6

how does motion perception help us determine an objects structure?

Answer 6

• help determine the shape via “kinetic depth effect”

Question 7

what is the kinetic depth effect?

Answer 7

• when shapes are stationary, they’re 3D shape info is unclear
• motion allows us to infer the 3D shape

Question 8

how does motion perception help us interpret actions?

Answer 8

• static poses are ambiguous
• movement clears ppl’s actions & interactions

Question 9

how was the phenomenon of interpreting actions via movement shown?

Answer 9

• point light “walkers”
• infrared dials placed on joints
• could only see “dots”
• it was possible to make out actions via movement of these dots

Question 10

the condition when someone can no longer perceive motion is …

Answer 10

AKINETOPSIA

Question 11

what are the effects of akinetopsia?

Answer 11

can see that things had moved, but couldn’t see them MOVING

Question 12

when do we perceive motion? (4)

Answer 12

1. real motion (smth actually moving)
2. illusory motion (nothing actually moving)
   - static image or apparent motion
3. motion aftereffects
4. induced motion

Question 13

what occurs in induced motion?

Answer 13

moving background or object causes a stationary object to appear to move

Question 14

what occurs in motion aftereffects?

Answer 14

after viewing a moving stimulus for a while, a stationary object in the scene then appears to be moving in the opposite direction

Question 15

apparent motion only works if the dots are _____ _____ _____

Answer 15

SUFFICIENTLY CLOSE TOGETHER

Question 16

if dots are too ___ apart, the ____ ____ is too fast, motion perception ceases to occur

Answer 16

FAR
ALTERNATION RATE

Question 17

for apparent motion to occur, as separation _____, alternation rate needs to _____

Answer 17

INCREASES
DECREASE

Question 18

what is Korte’s Third Law of Apparent Motion?

Answer 18

1. if 2 dots are further apart, they must be flashed less quickly to still be able to notice the “motion”

Question 19

when will apparent motion fail?

Answer 19

when 2 dots are to far apart & flashing is too quick

Question 20

why does apparent motion fail in certain cases?

Answer 20

because our brain assumes that the object cannot move b/w the 2 positions so quickly

Question 21

apparent motion is mostly ____ to colour changes

Answer 21

INSENSITIVE

Question 22

colour can be used to ________ apparent motion

Answer 22

DISAMBIGUATE

Question 23

motion can also make it ____ to notice changes

Answer 23

HARDER

Question 24

why does motion induce change blindess?

Answer 24

• when things are moving, there are transient signals associated W/ ALL OBJECTS in the scene (NOT JUST THE ONES CHANGING)
• attention is NO LONGER drawn preferentially to the changing object, so changes aren’t noticed

Question 25

when stationary, ____ to notice change

Answer 25

EASIER

Question 26

when moving, ____ to notice change

Answer 26

HARDER

Question 27

why doesn't change blindness occur in everyday life?

Answer 27

because there is no interjecting blank screen b/w 2 scenes of moving objects - thus, change is CUED

Question 28

apparent contrast determines the ____ ____

Answer 28

APPARENT SPEED

Question 29

according to the footsteps illusion experiment, higher the contrast = ...

Answer 29

FASTER THE SPEED

Question 30

what is the aperture problem?

Answer 30

if you can't see the ends of the line, the movement of the line is ambiguous - movement of the line is determined by the terminators (where the line touches the aperture)

Question 31

when we can see the actual ends of the line, we can see its ____ ____

Answer 31

ACTUAL MOTION

Question 32

anytime you can't see the actual terminators of a line, you _____ determine the ___ ____ of the line

Answer 32

CAN'T, ACTUAL, MOTION