Object-based attention

Question 1

Explain the Rock and Gutman (1981) experiments

Answer 1

participants have to focus on one of the two abstract figures that are overlapping in space
After the appraisal rating, sudden memory recalling task on if they notice the other response
participants mostly do not recall the other overlapping stimulus

Question 2

Explain the reason to conduct the Tipper and the details

Answer 2

The Rock and Gutman experiment looked at memory, not perception

details
have the participants to attend to one of the objects, then name the ignored one
slower RT if asked to name the ignored one

Reason
negative priming
priming = higher accuracy and shorter RT when naming something that you’ve seen
negative priming = lower accuracy and longer RT when naming something that you’ve deliberately ignored

Question 3

The Duncan experiment

Answer 3

the stimulus can differ in four dimensions (box size, open of the box, direction of the line, the format of the line)
the stimulus flashes rapidly, then the participants were told to only focus on two of the four attributes

If the reporting attributes = same dimension = higher accuracy
If the reporting attributes = different dimension = lower accuracy

object-based attention theorists: attention is focused on only one of the dimensions, which increases the accuracy

Question 4

Explain cueing effect under object-based theory, and the occluding bar

Answer 4

three conditions
same location, same object, different object
the distance between same object and different object is remained constant
results show that
faster RT for same object than different object
contradict with the spatial theorists (since distance already the same > therefore RT should not differ between the two conditions)

after adding the occluding bar, results are the same > showing that the cueing effect goes over boundaries

Question 5

1. What is the cause of visual neglect
2. What is visual neglect
3. Briefly name the visual streams

Answer 5

1. damage of the parietal lobe
2. not blindness, but failure to allocate attention to the objects in that visual field
3. Top = dorsal = where (where the parietal lobe is); bottom = ventral = what

Question 6

How to temporarily remove the neglection

Answer 6

by using cueing effect
experiment shows that
for instance the right parietal lobe is damaged = left visual neglect
valid and invalid cueing of the object on the right visual field is normal
valid cueing on the left = no big difference to the normal visual field
however, if invalid cue = massive increase on RT

Question 7

Explain extinction of visual neglect and the two possible explanations to it

Answer 7

If there is only one item in the damaged visual field > can perceive
If there are two items in the damaged visual field > only one item is perceived

Possible explanations
LS theory
> there are two objects that went through the limited channel capacity and compete to go through the filter, but only one can for patients

Capacity theory
> recognition requires the activation of the neural structures
> the damaged hemisphere hinders the activation of the neural structures, therefore provides less bottom-up stimulation for further process

Question 8

Explain Balint’s Syndrome, and how is it consistent with FIT

Answer 8

caused by bilateral lesions of the parietal and/or occipital lobe
patients cannot attend and focus to individual objects and see more than one object at a time (simultanagnosia)
due to optical ataxia (cannot move eyes > fixated overt attention)
also happens when objects overlap

consistent with FIT that attention is needed to bind the features of the stimuli together. Since attention cannot be allocated to both items at a time = illusory conjunctions

Question 9

Explain the dilemma on attention and inhibition between object-based and spatial theorists

Answer 9

object based
> attention is on the object, and inhibition of return is also on the object instead of the space
spatial
> attention is on space, and inhibition of return on space

Question 10

experiments supporting the object-based theories on inhibition and neglection

Answer 10

tipper (1991)
> first used peripheral cue to the left object
> then rotate the objects with a SOA by 90 degrees
> show that the inhibition happens to the object, even though it was rotated 90 degrees

Behrmann and tipper (1994)
> barbell-like stimulus, connected with a line
> participants had to react to the left side of the stimulus (showing slower RT > makes sense)
> then the stimulus was rotated 180 degrees
> Now the RT on the right (the left-side of the stimulus originally) = slower RT
> only works if there is a line in the middle making it a single object