lecture 11

Question 1

What is modularity?

Answer 1

There are different modules in the ventral and dorsal stream that are important for different types or specializations of processing

Question 2

What is the Simon effect? What two types of task are there? What is the exception of this effect?

Answer 2

• Subjects are shown a shape and have to either press a right or left key
• If the key is on the same side as the object (congruent task), the reaction time is shorter (vs incongruent task)
• This is because your brain automatically initiates an action with the corresponding side of the body (hand)
• The exception is with affordances, where you gave to grasp it in a particular way

Question 3

What is the difference between change blindness and inattention blindness?

Answer 3

• With change blindness the change happens off screen, and it works because you cannot attend to everything you see on-screen.
• With inattention blindness the change happens right in front of your eyes but you don’t notice it because you are paying attention to something else.

Question 4

What did Levin et al study about the awareness of change blindness?

Answer 4

• Subjects were shown a video with changes between scenes
• They usually did not notice this
• But they overestimated how well they would be able to notice such changes.

Question 5

How did Mack and Rock study inattention blindness?

Answer 5

• Subjects were shown a cross and had to determine which line was slightly longer
• This occupied their attention and they did not notice a shape coming into the image as well
• they could not determine what shape had appeared.

Question 6

What happens in people with Hemi-spatial neglect and what area is damaged? Why is it only when this area is damaged

Answer 6

• People with this impairment have damage to the right-parietal lobe.
• This is because the right parietal lobe processes both visual fields while the left only processes the richt visual field.
• Subjects are not aware of the left side of their visual field and usually other things too like the left side of their body?

Question 7

What did Bisiach and Luzatti discover about the Hemi-spatial neglect?

Answer 7

• This neglect is present in imagery too.
• Subjects had to imagine a place that they were familiar with and look at it form a specific angle
• When the angle changed they reported those parts that were now in the right side of their imagined visual field
• So they were still only aware of the left side

Question 8

How did Vuillemir prove that the Hemi-spatial neglect is attentional and not visual?

Answer 8

• Participants had to guess what something was based on fragmented parts that were shown (umbrella)
• When an object was previously shown on their unconscious visual field and so that side was familiar with it, the time needed to recognize the object decreased.
• SO visual processing still happened without them being consciously aware of it

Question 9

How did Marshall Halligan show that thins on the left visual field still gets processed in a Hemi-spatial visual neglect?

Answer 9

• People with the Hemi-spatial neglect where shown two houses of which the left (unconscious side was burning) side of the house was burning
• They did not know why but they preferred to live in the non-burning house.

Question 10

What does Double dissociation in near and far space show about hemi-spatial visual neglect?

Answer 10

People usually have either a neglect of far things, like visual. Or they have a neglect of near things, like the own body.

Question 11

What is object-based neglect?

Answer 11

• You are unaware of the left side of objects, instead of the left side of the visual field (hemi-spatial neglect)

Question 12

How does motion parallax give us information about what is further away?

Answer 12

• Things that are further away move more distance on the retina than close things

Question 13

How does moving around in the world give more information about monocular depth cue of occlusion? What two kinds of changes can happen when you move around?

Answer 13

If we move trough the world and an object occludes another, then the foreground changes from the background
- In accretion you see more of the background
- In deletion you see less of the objects.

Question 14

What is the corollary discharge theory? What two typers of signals are there and how are they integrated. In what two ways can you see movement and when is this difficult?

Answer 14

• There is the Competatory discharge signal (CDS)of eye movement and the Image motion signal (IMS) of movement on the retina. These are compared but the CDS and IMS.
• When you move your eyes or body, the image on your retina moves. You know your eyes or your body are moving instead of the outside world because your visual cortex is informed about these movements. (Only IMS)
• It could also be that an object stays in place but you eyes moves, this means the object is moving and you are tracking it. ( ONLY CDS)
• WHen there is both CDS and IMS it is difficult to detect movement.

Question 15

How did Rizzolatti et al discover the Mirror neuron system?

Answer 15

• A monkey’s neurons fired not only when doing an action but also when looking at that action.

Question 16

How did Lacoboni and Dapretto study The mirror neuron activity in monkeys?

Answer 16

• ## They measured brain activity when an object was grasped by the monkey and when it observed looking at someone picking up the object.

Question 17

What did Umita et al discover about the mirror neuron system?

Answer 17

• They discovered that the mirror neuron system is highly activated by the intention of an action.
• So when there was something to pick up and it was picked up there was more activity than without an object.
• Even if they could not see the object (but knew it was there)

Question 18

What is the Alien-Hand syndrome? How was it shown by Riddoch et all?

Answer 18

• People with this impairment cannot suppresses affordances and make the action that their brain automatically plans to do with an object.
• People with this impairment always picked up a cup with the hand that could most easily pick it up by the handle, rather than the instructed hand.
• It was affected when the affordance was opposite from the instructed hand.

Question 19

How did Philips and Ward study affordances in people?

Answer 19

• They measured reaction time of people.
• They had to press a key with the left or right hand, but the instruction was shown above a picture of a frying pan.
• When the handle corresponded with the side of the button press, the reaction time was similar whether the handle was facing toward or away from the subject.
• But when the handle was on the other side of the button press, reaction time was slower when the handle was facing toward them.

Question 20

What did Grezes and Decety study about affordances?

Answer 20

• People were shown blobs or actual objects with affordances. they also had to answer questions about the object that had to do with handling them only with the objects.
• They Compared brain activity between objects with and without and affordance
• Some brain areas were active only when perceiving the object with an affordance (frontal and parietal lobe)