Task 6

Question 1

Who got a nobel prize for research on split-brain patients?

Answer 1

Roger Sperry

Question 2

What is a confounding factor in many older studies of split-brain patients?

Answer 2

Their brains weren’t fully split - they often forgot about the anterior and posterior commissure or other smaller connections.

Question 3

In general, the nature of split brain research leads to some limitations. What are these?

Answer 3

• Small Samples
• Low generalizability - brain hemispheres are supposed to be interconnected and cannot be studied as separate entities
• High variability between patients
• Since learning can happen in a brain hemisphere, research that takes place too long after the commissurotomy will be confounded by this

Question 4

What are three methods of making visual stimuli available to one brain hemisphere only?

Answer 4

T-scope
Z-Lens
Brief Exposure

Question 5

What is the difference between the left and right hemispheres when it comes to object recognition?

Answer 5

The right hemisphere knows what it sees, how to interact with objects, and triggers emotional reactions and the left hemisphere can name things and is important for self-recognition

Question 6

The right hemisphere performs better on visual and spatial tasks. What principle is a caveat here?

Answer 6

The superiority is manipulo-spatial. That means, it is only significantly better, if the objects have to be physically manipulated.

Question 7

Which hemisphere is important for face recognition?

Answer 7

The right one

Question 8

Describe Levy et al.’s chimeric figures study.

Answer 8

Participants were exposed briefly to a series of faces where the two halves were different people. When given a set of normal comparison faces, participants indicated that they saw those faces, that match the left sides (right hemisphere) of the ones they saw briefly.

Question 9

How does Eccles argue, that there is only one consciousness?

Answer 9

He says that language is the only mean by which consciousness becomes observable.

Question 10

How does Sperry argue, that there are two consciousnesses?

Answer 10

The hemispheres are not aware of what happens in the other

Question 11

What question do “alien-hand phenomena” answer (or at least point in one direction)?

Answer 11

Whether the right hemisphere can produce intelligent behavior on its own

Question 12

What is cross-cueing?

Answer 12

When one hemisphere infers on what is going on in the other by means of observing the other’s overt responses.

Question 13

When the left hand draws the answer to a question the left hemisphere doesn’t understand on the right hand, this is an example of the right hemisphere using ___ to communicate with the left one.

Answer 13

Cross-cueing

Question 14

Describe an experiment where it was visible, that the right side has a sense of self.

Answer 14

When the participant rated himself negatively, he laughed. This means the right hemisphere understood the irony of his action but the left hemisphere couldn’t explain the laughter.

Question 15

According to the theory of interpreter systems, does dual consciousness exist?

Answer 15

No

Question 16

How does Gazzaniga explain previous indications of right hemisphere intelligence using his modules view?

Answer 16

He says that responses previously interpreted as indicating right-hemisphere consciousness are the product of nonconscious right hemisphere modules that can perform cognitive tasks

Question 17

The question of consciousness on the right hemisphere is heavily debatable. What tends to be something that much research can agree on?

Answer 17

There might be primary consciousness in the right hemisphere, but reflective consciousness and higher-order cognitive functions are restricted to the left.

Question 18

What are five basic arguments for split consciousness?

Answer 18

1) Responses are dependent on which visual field is used
2) There is hemispheric specialization
3) Post-hoc confabulations after right hemispheric actions
4) Hemispherical individual loci of attention
5) Inability to compare across midline

Question 19

What are points of criticism regarding the first basic argument for split consciousness, that patients are unable to compare across the midline?

Answer 19

• Doesn’t hold for every patient

- Under the right circumstances, patients can compare across the midline consistently

Question 20

What is an argument for not using post-hoc confabulations as a reason to assume split consciousness?

Answer 20

It is not unique to split-brain patients. Healthy individuals confabulate (choice blindness, priming, etc.)

Question 21

How can a modified attentional blink paradigm be used to refute the argument, that attention is hemisphere-specific?

Answer 21

When being shown an attentional blink paradigm which is split between the two visual fields and target 1 appears in one field and target 2 appears in the other field shortly after, the attentional blink still exists -> Attention is not split

Question 22

How does the idea of split perception explain cognition in split brain patients?

Answer 22

Perceptual information is not shared between the hemispheres, causing maximal hemispheric specialization. Both hemispheres however report to one conscious agent.

Question 23

Which older theories of consciousness does the idea of split perception contradict?

Answer 23

Integrated Information Theory; Global Workspace Theory; Recurrent Processing Theory (to a degree)

Question 24

What are some neurological arguments for a unified consciousness?

Answer 24

• Subcortical areas are still unified

- Conscious unity might be related to functional unity, which is still possible in split brains