Deck 12: Eye Movements and Perception of Natural Scenes

Question 1

VanRullen and Thorpe suggested that a natural scene can be categorized in about:

A) 10 ms
B) 1 s
C) 2 s
D) 150 ms

Answer 1

D

Question 2

The contrast sensitivity function for chromatic gratings is shifted towards lower spatial frequencies than that for luminance gratings, though in natural scenes the spatial content provided by colour and by luminance is the same. How did Parraga et al. reconcile this with the idea that the human visual system is matched to the properties of the world?

A) They suggested that colour is a such a late addition to vision that evolution has had no time to shape it
B) They suggested that colour is most useful when objects are large
C) They suggested that, at a viewing distance of about 40 cm, a distance at which one would pick ripe fruit, the properties of the scene and of the visual system would match
D) They suggested that colour is important in processing of coarse moving stimuli

Answer 2

C

Question 3

In humans, the greater sensitivity to vertical and horizontal contour compared with oblique is thought to arise because:

A) There are more vertical and horizontal contours in natural scenes
B) Humans have an aesthetic preference for these orientations
C) Humans walk upright on a flat earth
D) None of these

Answer 3

A

Question 4

Juricevic et al. showed that patterns caused greater visual discomfort if their amplitude spectra:

A) Followed the 1/f law
B) Were curtailed
C) Were scrambled
D) Had amplitudes of spatial frequencies close to 3 c deg⁻¹ that were greater than predicted by the 1/f law

Question 5

Huang et al. showed that, in natural scenes, objects were more likely to be above rather than below the horizontal line of sight beyond a distance of:

A) 5 m
B) 10 m
C) 2 m
D) 20 m

Question 6

When there is no clear distance information in a scene, observers perceive the distance of an object to be about:

A) 50 cm
B) 3 m
C) 10 m
D) 20 m

Question 7

Categorization of scenes tends to be faster when:

A) It is between indoor and outdoor scenes
B) The scene contains man-made objects
C) The scene contains natural objects
D) It can be done from a low spatial frequency representation

Question 8

Joubert et al. suggested that:

A) Objects are categorized more quickly than scenes
B) Scenes are categorized more quickly than objects
C) Scenes are categorized by first identifying typical objects within them
D) The scene itself, and the objects within it, are categorised in parallel, with the possibility of interaction between the processes

Question 9

Horizontal movement of the eyes towards the nose is caused by which of the following muscles?

A) Medial rectus
B) Lateral rectus
C) Superior oblique
D) Inferior oblique

Question 10

The lateral rectus muscle is innervated by which of the following nerves?

A) Trochlear
B) Optic
C) Abducens
D) Oculomotor

Question 11

Masson and Stone showed that, when a participant is asked to follow a moving object with their eyes, they initially track:

A) One of the object's corners
B) The whole object
C) The direction which is an average of the directions orthogonal to its contours
D) Its centre of gravity

Question 12

The signals which underlie conscious perception of motion and those which control pursuit eye movements are different in part because:

A) Humans can perceive movements which they cannot track with their eyes
B) Eye movements are made during sleep
C) Eye movements cannot be made to stimuli moving in depth
D) During pursuit, the eyes follow small changes of target velocity of which the participant is unaware

Question 13

What is the approximate mean number of saccades made very second by human observers?

A) 10
B) 2
C) 5
D) 20

Question 14

In the control of eye movements, in which brain region do neurons respond to movement of the target in the world, rather than simply on the retina?

A) MST
B) MT
C) Superior colliculus
D) Lateral geniculate nucleus

Question 15

Melcher and Colby argued against the possibility of a detailed trans-saccadic memory, on the grounds that:

A) Peripheral vision is coarse
B) Eye movements are imprecise
C) It would decay during a saccade
D) Objects can change their relative positions during a saccade, because of object or observer motion

Question 16

Prime et al. found that around four items could be remembered when a saccade intervened between presentation of the two arrays, except when they applied to TMS to which brain regions?

A) Inferior temporal lobes
B) Frontal or parietal eye fields
C) Cerebellum
D) S1

Question 17

Latour found that the probability of detection of a flash of light turned on around the time of a saccade was lowest:

A) 50 ms before saccade onset
B) 75 ms after saccade onset
C) 5 ms before saccade onset
D) 5 ms after saccade offset

Question 18

Which of the following visual properties did Burr et al. not find to be compressed immediately before a saccade?

A) Depth
B) Space
C) Time
D) Number

Question 19

During the task of making a cup of tea, people tend to gaze at:

A) High contrast objects
B) Their visitor
C) Relevant objects, such as the kettle
D) None of these

Question 20

Warren presented a sentence in which one syllable had been completely replaced by a cough. His listeners could:

A) Accurately report the location of the cough in the utterance
B) Report that a syllable was missing
C) Not identify the syllable
D) Hear the sentence as though the cough had not occurred

Question 21

Osorio and Vorobyev suggested that the advantage of trichromatic over dichromatic vision lay in:

A) Increased ability to distinguish leaves from fruit
B) Increased ability to distinguish one leaf from another
C) Increased ability to distinguish fertile from non-fertile females
D) Increased ability to distinguish health and disease

Question 22

The 1/f law describes:

A) Sensitivity to coloured gratings
B) The decline in amplitude of spatial components in natural scenes with increases in spatial frequency
C) The reduction in sensitivity to low spatial frequencies
D) Flicker sensitivity

Question 23

The Specific Distance Tendency reported by Gogel probably arises because:

A) The natural vergence angle means that the eyes converge at about 3 m
B) Beyond arms' length, distance of objects is less important
C) The distance of objects in natural scenes peaks at about 3 m
D) Accommodation is not informative about a change of distance beyond 5 m

Question 24

Categorization of scenes is faster, when the categorization is:

A) Natural vs man-made
B) Indoor vs outdoor
C) Beach vs mountain
D) Dog vs horse

Question 25

Horizontal movement of the eyes away from the nose is caused by which of the following muscles?

A) Medial rectus
B) Lateral rectus
C) Superior oblique
D) Inferior oblique

Question 26

After about 200 ms, in which direction to the eyes move when pursuing a moving object?

A) The direction orthogonal to one of the object's sides
B) The direction in which the whole object is moving
C) The direction which is an average of the directions orthogonal to its contours
D) None of these

Question 27

Losses of sensitivity during a saccade are highest for:

A) Isoluminant gratings
B) High spatial frequency luminance gratings
C) Stationary bright dots
D) Low spatial frequency luminance gratings

Question 28

'Grey-out' of the image of a room occurs around the time of a saccade when:

A) The illumination is turned on for as long as the saccade lasts
B) The illumination is turned on for 5 ms at some point during the saccade
C) The illumination is turned on when the saccade begins and is left on for 40 ms after the saccade has ended
D) The illumination is turned on 40 ms before the saccade begins and is left on for 40 ms after the saccade has ended

Question 29

Image regions which are fixated tend not to:

A) Contain high spatial frequencies
B) Have higher contrasts than their surroundings
C) Have intensities which are different from their surroundings
D) Move

Question 30

Listeners can perceive accurately sounds recorded in a room which causes reverberation, provided that:

A) They hear the sound through headphones
B) The test word occurs in a context of other words recorded with the same reverberation
C) The test word is presented at high intensity
D) They are familiar with the test word without reverberation

Question 31

What is the oblique effect, and how is it to be explained?

Question 32

What is the 1/f law? Why does human contrast sensitivity not reflect it?

Question 33

Why is it faster to categorise a scene as natural or man-made than as indoor or outdoor?

Question 34

Give an example of physiological and another of behavioural evidence for spatial remapping across saccades.

Question 35

What is suppressed during saccadic suppression?