6: Visual Attention

Question 1

What is visual attention?

Answer 1

Serves as a mediating mechanism, enabling us to grant priority of processing to certain aspects of the visual scene.

Question 2

Focusing on specific objects and ignoring others is what?

Answer 2

Selective attention.

Question 3

Scanning the fovea over objects of interest allows the visual system a _____ view.

Answer 3

High acuity.

Question 4

Define saccades and fixations.

Answer 4

Saccades: rapid eye movements.

Fixation: pauses between saccades (~300ms).

Question 5

What is meant by scene characteristics?

Answer 5

High saliency features grab our attention (e.g. high contrast, bright colors).

Question 6

What is attentional capture?

Answer 6

High salience feature causes an involuntary shift of attention (sudden movements, loud sounds).

Question 7

What three factors make up a saliency map?

Answer 7

Orientation, colour, contrast.

Question 8

_____ often drives the first few fixations, but later scene scanning is influenced by _____.

Answer 8

Saliency; cognitive factors.

Question 9

Knowledge of what is normally contained in typical scenes is known as?

Answer 9

Scene schemas.

Question 10

How can interests and goals influence attention?

Answer 10

Different parts of a scene or objects are important for different goals. Same image can contain different tasks (e.g., remember clothing, determine age of subjects).

Question 11

How do task demands influence attention?

Answer 11

Gaze is directed to various objects with specific timing as the task unfolds.

Question 12

Eye movements usually precede a bodily motor action by _____.

Answer 12

A fraction of a second.

Question 13

Attention speeds up _____. _____ reduces reaction times.

Answer 13

Responding; pre-cuing.

Question 14

Attention alters the _____ of visual stimuli.

Answer 14

Appearance.

Question 15

Attention enhances the firing of neurons. What does neuronal activity depend on, in this case?

Answer 15

Shape, size, orientation, AND attention.

Question 16

The boost in firing rate is quite small at the level of the _____, but is bigger in _____. What is the order of this sequence?

Answer 16

Primary visual cortex; higher order visual areas.

V1 → MT → MST.

Question 17

Attention to objects increases responses of _____.

Answer 17

Specific modules.

Question 18

What increases BOLD signal in retinotopic maps? What can experimenters do with this information?

Answer 18

Attention to a region of space.

Experimenter can “read” where the subject is covertly attending to.

Question 19

Attention has been shown to re-shape _____.

Answer 19

Receptive fields.

Question 20

Attention synchronizes neural activity between areas of the brain. Stimulus 1 activates location A in V1 and location C in V4. Stimulus 2 activates location B in V1 and location C in V4. Activity for sites A and C synchronize when what happens?

Answer 20

Attention is directed to stimulus 1.

Question 21

What is the binding problem?

Answer 21

How are individual features combined to create our perception of a coherent object?

Question 22

Describe the process outlined by the feature integration theory.

Answer 22

Object → preattentive stage (features separated) → focused attention stage (features combined) → perception.

Question 23

Give an example of an illusory conjunction.

Answer 23

Seeing a red Q and a blue T, reporting blue Q.

Question 24

Define Balint’s Syndrome.

Answer 24

Damage to parietal lobe = difficulties focusing attention on individual objects.

Question 25

Items that POP OUT are _____. Give an example.

Answer 25

Visual primitives.

Find a red vertical bar amongst green vertical bars.

Question 26

Pop-out/feature search uses _____ processing.

Answer 26

Parallel/pre-attentive.

Question 27

Give an example of a conjunction search. What type of processing is used and why is attention required?

Answer 27

Find an “L” among “T”s.

Serial/attentive processing.

Attention is required to bind primitives.

Question 28

List three highlights of Goldstein’s PSA regarding attention and driving.

Answer 28

Hands-free performance similar to phone-in-hand.

Phone conversation ≠ passenger conversation.

Attribution of carelessness/responsibility.

Question 29

List the two “blindness” terms regarding attention and define them.

Answer 29

Inattentional Blindness: when attention focused on one task, very salient stimuli that are unrelated to the task sometimes not perceived.

Change Blindness: difficulty detecting changes in scenes.

Question 30

What is an example of change blindness blindness?

Answer 30

Continuity errors in movies.

Question 31

Is perception without attention possible? Explain.

Answer 31

Depends on task difficulty.

Perception of “extra” task appears to depend on difficulty of “main” task.

Question 32

What are distracters? What did Lavie et al. find regarding them?

Answer 32

Task-irrelevant stimuli than can affect performance.

Lavie at al. found distracters have smaller effect in more difficult tasks.