Psyc 330 Ch. 7

Front 1

Saccades

Back 1

most frequent eye movements characterized by rapid, "jump and rest" foveations of objects that occur when we scan a scene or read

Front 2

Smooth pursuit movements

Back 2

Eye movement characterized by a smooth motion without abrupt stars and stops.
Allows us to maintain foveation of moving objects.

Front 3

When are objects clearest?

Back 3

when we look directly at them

Front 4

differentiate between cones and rods

Back 4

cones = colour, fine detail

rods = light/ motion

Front 5

Fovea

Back 5

area in the back of the eye consisting entirely of cones. area of clearest vision

Hint 5

Front 6

why do we have both rods and cones? why not just cones?

Back 6

advantage of rods: sensitive to motion in peripheral vision, has help us survive and evolve. rod vision better for fainter images.

Front 7

why do we move our eye?

Back 7

so we can see things clearly

Front 8

foveate

Back 8

to look directly at something

Front 9

how do animals that cant move their eyes compensate?

Back 9

with head movements

Front 10

vestibular movements

Back 10

eyes move in head (while head is moving)

Front 11

vergence movements

Back 11

eyes move closer together as things get closer to us

Front 12

microsaccades and drifts

Back 12

jiggling of eyes due to stimulation of photo-receptors

Front 13

how are saccades different in adults and children?

Back 13

adults can make larger (30 degree) saccades

than infants (10 degrees) (known as hypometric saccade)

Front 14

name ways to monitor eye movements

Back 14

1. post-experiment video review

2. contact lens method

3. electrooculogram

4. LED-based corneal reflection

5. video based corneal reflection

Front 15

post-experiment video review for monitoring eye movements

Back 15

experimenters set up video recorder to know when subjects move eyes

cons: lots of work to look at hours of video, many get tired of watching recordings so theyre not accurate, can't get subjects back when finally see that they moved eyes

Front 16

contact lens method of monitoring eye movements

Back 16

subject has to wear lens with wire and mirror, if ss moves eyes at all beam of reflected light moves to detect eye movement

Front 17

Electrooculogram to monitor eye movements

Back 17

works well if already studying ERPs, like EEG, electrodes placed around eye to detect movement

cons: not very precise

Front 18

LED-based corneal reflection method to monitor eye movements

Back 18

goggles with LED. Eye movements cause reflection differences, head stabilized.

Front 19

Video based corneal reflection method to monitor eye movements

Back 19

infrared camera and light source. eye movements cause reflection to change. ss cant see the light. can create "hot spots" of where people are looking on screen

Front 20

what are the 3 pairs of ocular muscles responsible for?

Back 20

1. up and down motion

2. side to side

3. rotational

Front 21

What brain areas are involved in saccade programming?

Back 21

superior colliculus is active prior to and during saccades and attn shifts

these cells are sensitive to visual movement and location

Front 22

Stimulus - driven saccade

Back 22

saccades initiated by sensory events

Front 23

goal-driven saccades

Back 23

saccades initiated on the basis of the observers goals and intentions

Front 24

True or False: initiation of saccades are generally under voluntary control?

Back 24

True

Front 25

True or False: saccades can be voluntarily suppressed?

Back 25

True, but saccade programming can be both goal-driven and stimulus driven.

Front 26

Describe how saccades are ballistic?

Back 26

once a particular trajectory has been calibrated and then the saccade is triggered, the eye can move without further programming.

Front 27

what are the advantages and disadvantages of ballistic eye movements?

Back 27

A: once initiated they are extremely rapid and require no additional feedback

D: during programming, they require precise information about their destination. calibration is a relatively slow process

Front 28

Why are smooth pursuit eye movements not ballistic?

Back 28

Signals sent to the eye muscles must be constantly updated and revised via a feedback loop that codes current object position and cognitive expectations about motion. allows us to maintain tracking accuracy.

Front 29

which is faster, saccades or smooth pursuit eye movements?

Back 29

saccades - 220 ms

Front 30

Under-pursuit

Back 30

when the position of an object's image on the retina slips out of the foveal regions thus becomes blurry

Front 31

Describe Grimes (1996) visual suppression study

Back 31

method: ss wore eye-movement monitoring devices. during brief intervals when eyes in motion, visual scene would change

Results: ss unaware of changes in scene

Front 32

Saccade suppression

Back 32

attention becomes disengaged during saccade, and to avoid blurring effect, visual analysis is suppressed then updated once saccade is complete

Front 33

How are smooth pursuit eye movements like analog attention shifts?

Back 33

attention remains engaged during smooth pursuits

Front 34

Meridian Effect

Back 34

target-detection response slower when cue and target are on opposites sides of the unseen vertical meridian that divides the right and left hemifields

Front 35

Why are saccades subject to the meridian effect?

Back 35

because direction re-calibration must occur when making successive saccades in different directions, which requires extra time.

Front 36

Express Saccade

Back 36

Very short latency (100ms) saccades that are produced by the fixation-offset effect.

result of attentional disengagement prior to the saccade preparation process

Front 37

Experiment: Express Saccade

Back 37

method: 1. overlap condition - fixation point remained visible, 2. gap condition - fixation point disappears shortly before target

Findings: saccade quicker when fixation point disappears

Why?: allows us to disengage our attn. before saccade

Hint 37

Front 38

anit-saccade

Back 38

target appears in left hemifield, saccade to the opposite direction to the right hemifield

Front 39

pro-saccade

Back 39

saccades made directly to target locations.

express saccades only occur during this type of task.

Front 40

Differences between saccades and smooth pursuit movements

Back 40

Front 41

Feature map

Back 41

Feature map sends signal to master map about where something could be.