Chapter 2: Localisation

Question 1

What are the major parts of the human brain?

Answer 1

● cortex
● cerebellum
● limbic system
● brain stem

Question 2

Cortex

Answer 2

the layer of neurons with a folded surface covering the brain on the outside. Largest part of the human brain associated with high-order functions such as though or voluntary action.

Question 3

Frontal lobes

Answer 3

One of the four lobes in the cortex
The frontal lobes are associated with reasoning, planning, thinking and decision-making, voluntary action, complex emotions, and so on

Question 4

Parietal lobe

Answer 4

One of the four lobes in the cortex
The parietal lobe is associated with movement,
orientation, perception and recognition.

Question 5

Occipital lobe

Answer 5

One of the four lobes in the cortex
The occipital lobe is associated with visual
processing

Question 6

Temporal lobes

Answer 6

One of the four lobes in the cortex
The temporal lobes are associated with
processing auditory information, memory and
speech.

Question 7

Corpus callosum

Answer 7

the structure of neurons that connect the left and right hemispheres

Question 8

Cerebellum

Answer 8

The brain region associated with motor control.

Question 9

The structures of the limbic system

Answer 9

Sometimes referred to as the emotional brain including the following structures:
● The thalamus has mostly sensory functions.
Nerves from almost all sensory organs reach
the thalamus as a final “hub” before they are
connected to the cortex.
● The hypothalamus is “below” the thalamus in
the brain and it is involved in such functions as
emotion, thirst and hunger.
● The amygdala is involved in memory, emotion
and fear.
● The hippocampus is important for such
functions as learning, memory and transferring
short-term memory to a more permanent store,
spatial orientation

Question 10

The brain stem

Answer 10

located underneath the limbic system. Main function is the regulate the basic vital processes such as breathing or heartbeat. Connects the brain to the spinal cord.

Question 11

Broca’s aphasia

Answer 11

The study of “Tan,” described the link between speech and writing impediment and a lesion in the frontal area in left hemisphere, which was later known as “Broca’s area.” The research supports strict localization.

Question 12

Wernicke’s aphasia

Answer 12

People with Wernicke’s aphasia have a general impairment of language comprehension, while at the same time speech production is intact. Wernicke’s area is located in the temporal lobe of the dominant hemisphere. The research supports strict localization.

Question 13

Cortical homunculus

Answer 13

A map of the sensory and motor cortex; what parts of the brain stimulates what parts of the body. The study was conducted by Wilder Penfield by the method of neural stimulation and supports strict localization.

Question 14

Lashley’s induced brain damage observations

Answer 14

A study conducted by Karl Lashley where he removed parts of rats’ brains after having taught them how to run through a maze. Change in behavior was observed after removing certain percentage of the cortex in the hopes of discovering where memory is localized. However, he found that rather than the removal of certain areas of the brain, certain percentage of cortex removed had a correlation to learning abilities. This was later to be known as the principle of mass action. This was further explained by equipotentially which refers to the ability of one part of the cortex to take over the functions of another part of the cortex.

Question 15

Relative localization

Answer 15

Currently supported by neuroscience; it admits localization for some functions under some conditions but also outlines the limits of localization.

Question 16

Lateralization

Answer 16

Lateralisation is the idea that the two hemispheres of the cortex of the brain are functionally different and that each hemisphere has functional specializations. Most mental functions are distributed across the hemispheres but there are specific processes that are specialized to one hemisphere e.g. the left is dominant for language, and the right excels at visual-motor tasks.

Question 17

Sperry and Gazzaniga (1967)

Answer 17

A: to investigate the extent to which the two hemispheres are specialized for certain functions.

M: An image/word is projected to the patient’s left visual field (which is processed by the right hemisphere) or the right visual field (which is processed by the left hemisphere). When information is presented to one hemisphere in a split-brain patient, the information is not transferred to the other hemisphere (as the corpus callosum is cut).

P: Sperry and Gazzaniga conducted three tests:

In the describe what you see task, a picture was presented to either the left or right visual field and the participant had to simply describe what they saw.

In the tactile test, an object was placed in the patient’s left or right hand and they had to either describe what they felt, or select a similar object from a series of alternate objects.

Finally, in the drawing task, participants were presented with a picture in either their left or right visual field, and they had to simply draw what they saw.

R: In describe-what-you-see task:
When a picture was presented to the right visual field (processed by left hemisphere), patients could describe what they saw. When presented to the left visual field, patients could not describe what was shown (sometimes reported that there was nothing).

In tactile tests:
When objects were placed in the right hand (processed by left hemisphere), patients could describe verbally what they felt and identify the object by selecting a similar object. When objects were placed in the left hand, patients could not describe what they felt and often guessed. They could, however, identify the object by selecting a similar object.

In drawing tests:
When a picture was presented to the right visual field, patients’ drawings were better when made by the left hand. When presented to the left visual field, the left hand was still better, which demonstrates the superiority of the right hemisphere for visual-motor tasks.

C: Both hemispheres are capable of forming emotional responses. However, the left hemisphere is dominant in terms of speech and language, whereas the right hemisphere performs better in visual-motor tasks (visual construction)

E: