Visual Attention

Question 1

What is saccade?

Answer 1

• Rapid, voluntary shifts in eye positions between steady fixations
• we voluntarily move our eyes when we are looking at a scene or reading

Question 2

Review circuitry for voluntary saccades

Answer 2

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Question 3

What are the pathways for saccades?

Answer 3

Posterior parietal cortex (LIP) and frontal eye field send signals to superior colliculus which sends signals mesencephalic and pontine reticular formations. These control eye movement

Question 4

WHat is bottom up attention?

Answer 4

Certain visual features e.g. distinctive color, movement, flashing light “catches our attention”

Question 5

What is top-down attention?

Answer 5

Delibaretly directed by the brain. You’re told what to pay attention to

Question 6

What are overt attention and covert attention?

Answer 6

Overt: changes in eye gaze direction
Covert: attention directed without gaze change

Question 7

What are consequence of attention?

Answer 7

Visual acuity, reaction times

Question 8

What are the two types of searches?

Answer 8

Pop-out search (target can be identified by one feature) and conjunction search (target defined by the conjunction of two or more features)

Question 9

What is Feature Integration Theory?

Answer 9

Spatial attention: attention to particular spatial location “glues” features together.
Each feature can be analyzed without attention in parallel within multiple feature maps (in specialized cortical areas)

Question 10

What is the effective stimulus?

Answer 10

V4 cell responds well to vertical and horizontal red bars in its RF

Question 11

What is the ineffective stimulus.

Answer 11

Does not respond to vertical and horizontal green bars in its RF

Question 12

What does FEF stimulation do?

Answer 12

It enhances (red) V4 cell response to a visual stimulus

Question 13

Review Frontoparietal attention network (last slide)

Answer 13

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Question 14

Describe the frontoparietal attention network for bottom-up attention

Answer 14

• input about conspicuous object is passed from visual areas in the occipital lobe to area LIP
• construction of salience map
• visual processing of a salient object is enhanced
• eyes may move to five are the object

Question 15

Describe the frontoparietal attention network for top-down attention

Answer 15

• attention effects occur first in frontal and parietal areas. Behavioral goals established here
• priority map in LIP and FEF
• visual processing enhances perception of selected object
• eyes may move