Question 1

Who were the neurosurgeons who performed the first major series of commissurotomies for the treatment of intractable epilepsy?

Accepted Answer

Vogel and Bogen were the neurosurgeons who performed the first major series of commissurotomies for the treatment of intractable epilepsy.

Question 2

This split-brain patient was asked to reach under the ledge with her left hand and select the object that appeared on the screen.She selected

Accepted Answer

The answer of This split-brain patient was asked to reach...

Question 3

One way of using the Z lens to test the left hemisphere's comprehension of spoken words is to

Accepted Answer

The answer of One way of using the Z lens...

Question 4

The right hemispheres of most split-brain patients

Accepted Answer

While the left hemisphere is generally considered to be the dominant language hemisphere in most individuals, studies have shown that the right hemisphere of split-brain patients can understand many spoken or written words and simple sentences. However, the right hemisphere typically lacks the ability to produce language in a meaningful way.

Question 5

Which of the following investigators,along with Sperry,played a major role in testing the original series of human split-brain patients?

Accepted Answer

Gazzaniga was a major collaborator with Sperry in studying the original series of human split-brain patients. The other investigators listed, while notable in their own right, did not play a major role in this particular research.

Question 6

Each hemisphere of a human split-brain patient is capable of completion.That is why on the chimeric figures test,each hemisphere sees

Accepted Answer

In a split-brain patient, each hemisphere is capable of completing the image on its own. Therefore, on the chimeric figures test, each hemisphere sees a complete, but different, face. This is because the left hemisphere primarily processes information from the right visual field, while the right hemisphere primarily processes information from the left visual field. As a result, each hemisphere sees only half of the face presented in the chimeric figure.

Question 7

During a test in which split-brain patients were asked to verbally specify which of two colors,red or green,had been presented in the left visual field,an interesting phenomenon was discovered.This phenomenon is

Accepted Answer

Cross-cuing refers to the phenomenon where split-brain patients use indirect signals or cues from one hemisphere to the other to communicate information. In the context of the test mentioned, even though the corpus callosum (which connects the two hemispheres of the brain) is severed in split-brain patients, they might still use other, more indirect ways to share information between hemispheres, such as facial expressions or sounds, to indicate their perception of color in the left visual field. This is known as cross-cuing.

Question 8

Visual information is presented to only the left hemisphere of a human split-brain patient by getting the patient to fixate on the center of the display screen and then

Accepted Answer

In split-brain patients, the left hemisphere processes information from the right visual field. Flashing information on the right side ensures it is processed by the left hemisphere.

Question 9

After the picture of a familiar object is flashed in the left visual field of a split-brain patient,the patient can

Accepted Answer

In split-brain patients, the corpus callosum, which connects the two hemispheres of the brain, is severed. When an image is presented to the left visual field, it is processed by the right hemisphere. The right hemisphere controls the left side of the body but does not have direct access to the speech centers, which are located in the left hemisphere. Therefore, the patient cannot verbally identify the object (ruling out A and E) but can use the left hand (controlled by the right hemisphere) to select the object, demonstrating nonverbal recognition (B). The right hand, controlled by the left hemisphere, would not be able to select the object because the information about the object was not transmitted to the left hemisphere (ruling out C).

Question 10

A spoon is presented in the left visual field of a split-brain patient,and an apple is simultaneously presented in the right.Then,the patient is instructed to reach into two bags (one with each hand)and feel around until he comes up with the object that was presented on the screen.However,before the objects are withdrawn,the patient is asked to tell the experimenter what he has in each hand.The patient is likely to say,"I have

Accepted Answer

The answer of A spoon is presented in the left...

Question 11

Cross-cuing is communication between the hemispheres of a split-brain patient that occurs

Accepted Answer

Cross-cuing in split-brain patients occurs externally, as the hemispheres cannot communicate directly due to the severed corpus callosum. Instead, one hemisphere may influence the other through external cues or behaviors.

Question 12

The decision to treat "terminal" epilepsy patients with commissurotomy was made on the basis of previous comparative studies that had shown that

Accepted Answer

Interestingly, commissurotomy reduced the incidence of seizures, rather than simply restricting them to one hemisphere as first predicted.

Question 13

According to the text,the independence of the hemispheres of split-brain patients tends to be overestimated because

Accepted Answer

The correct answer is D because all the statements contribute to the overestimation of the independence of the hemispheres in split-brain patients. A) highlights the bias in published discussions towards cases with more complete independence, B) points out the lack of focus on emotional information which can be shared between hemispheres, and C) mentions the use of simple tests that don't fully challenge the inter-hemispheric integration, all of which can lead to an overestimation of hemisphere independence.

Question 14

Chimera

Accepted Answer

Chimera is a term from mythology referring to a creature made up of parts from different animals. The other options relate to psychological and neurological studies, which are not associated with the term "Chimera."

Question 15

The Z lens was developed by

Accepted Answer

The Z lens was developed by Zaidel.

Question 16

A major advantage of the Z lens over conventional procedures for testing split-brain patients is that it

Accepted Answer

The answer of A major advantage of the Z lens...

Question 17

The helping-hand phenomenon was demonstrated in a test

Accepted Answer

The answer of The helping-hand phenomenon was demonstrated in a...

Question 18

After the picture of a familiar object is flashed in the right visual field of a human split-brain patient,the patient can

Accepted Answer

Split-brain patients have undergone a surgical procedure that involves severing the corpus callosum, the bundle of nerve fibers that connects the two hemispheres of the brain. As a result, information presented to the right visual field is processed by the left hemisphere of the brain, while information presented to the left visual field is processed by the right hemisphere. In split-brain patients, language production tends to be localized to the left hemisphere, while visuospatial abilities tend to be localized to the right hemisphere. This means that after a picture of a familiar object is flashed in the right visual field, split-brain patients can use their left hemisphere to say what the object was (option A), whereas using their right hemisphere, they could reach into a bag with their right hand and select the object that was presented from a group of test objects (option B). Therefore, the correct answer is D, because both options A and B are valid for split-brain patients in this scenario. Option C is incorrect because selecting the object using their left hand requires the involvement of the right hemisphere, which has limited language processing abilities in split-brain patients.

Question 19

What proportion of the digits recognized by healthy volunteers in the conventional dichotic listening test are typically those presented to the right ear?

Accepted Answer

In dichotic listening tests, the right ear advantage is typically observed, with about 55% of the digits recognized being those presented to the right ear due to the left hemisphere's dominance in processing verbal information.

Question 20

The study of lateralization of function has focused on the right hemisphere because

Accepted Answer

The study of lateralization of function has focused on the right hemisphere because the special abilities of the left hemisphere have been more apparent. While most people are right-handed (A) or dextrals (B), this is not the primary reason for the focus on the right hemisphere. Additionally, while the right hemisphere may be dominant in certain functions, it is not universally so (C).

Quiz 16: Lateralization, language, and the Split Brain