Space and Object-Based Visual Attention

Question 1

Describe the spotlight theory and support for it (Posner et al, 1980)

Answer 1

 Attention acts like a spotlight activating information from different regions of space
 Attentional cueing studies show different strategies:-
Exogenous – Bottom up reflex due to sudden change (flash/movement) which draws attention automatically
Endogenous – Top down instructions given (visual sign) that send attention to requested location

Question 2

Describe the zoom lens theory and support for it (Eriksen and St. James, 1986)

Answer 2

 Modification of spotlight theory proposing that focused attention can be adjusted when a task demands it
 LaBerge (1983) participants focused attention on single letter or whole words when required

Question 3

Criticisms of spotlight and zoom lens theory

Answer 3

Attention is an O shaped pattern, did not find that attention was best when target was nearest to cued location

Question 4

Describe attentional shifts and how they occur

Answer 4

 Focus of attention is instantaneous from one location to another without noticing distance travelled
 Spatial attention can be split across two locations

Question 5

What are the two different networks of visuo-spatial attention?

Answer 5

 Posterior – Expression of attention

 Anterior – Control of attention

Question 6

Describe the 3 interacting systems in the posterior network?

Answer 6

 Disengagement of attention – posterior parietal lobe permits processing of attended stimuli to end
 Shifts of attention – superior colliculus, controls eye movement and allows attention to be drawn from old to new location
 Engagement of attention – thalamus, blocks input of unattended sources

Question 7

What evidence is there for space-based attention?

Answer 7

 Unilateral visual neglect - Patients with unilateral parietal damage fail to acknowledge objects exist in the space opposite their lesion.
 These patients have difficulties disengaging attention

Question 8

What is extinction?

Answer 8

Symptom of visual neglect where patient cannot perceive objects on opposite side of lesion when it is shown simultaneously with another object that is presented on the same side as lesion

Question 9

What is pseudoneglect?

Answer 9

Seen in healthy non-lesioned brains, there is an attentional bias for the left side of space (Actors in a play always enter from the right of the stage when they want to be unnoticed)

Question 10

What is object based attention and support for it

Answer 10

 Attention can also be given to objects as well as space (Binocular rivalry)
 Participants shown two different overlapping images and asked to recall them later. They could only recall one of the images suggesting that the other image in the “spotlight” wasn’t processed.
 Attention is also prioritised showing it is easier to judge two attributes belonging to the same object than the same attributes belong to different objects