Localisation of Function

Question 1

What does localisation of function refer to

Answer 1

The principle that specific functions, for example language, memory or hearing have specific locations in the brain

Question 2

When was there a growth in interest in localisation of brain function

Answer 2

In the early 19th century, undoubtedly influenced by phrenology

Question 3

What area of the brain is responsible for the generation of voluntary motor movements

Answer 3

The motor cortex

Question 4

Where is the motor cortex

Answer 4

In the frontal lobe of the brain, along the precentral gyrus

Question 5

How does the motor cortex work

Answer 5

Both hemispheres have one, they are lateralised. Different parts of the motor cortex exert control over different parts of the body, with regions arranged logically next to each other, for example the region that controls the foot is next to the region controlling the leg

Question 6

What area of the brain detects sensory events

Answer 6

The somatosensory cortex

Question 7

Where is the somatosensory cortex

Answer 7

It is in the parietal lobe of the brain, in the postcentral gyrus. Both hemispheres have one, and they are lateralised

Question 8

What does the somatosensory cortex do

Answer 8

It processes information related to touch. Using sensory information from the skin it produces sensations of touch, pressure, pain and temperature which it localizes to specific body regions.

Question 9

What is the visual centre of the brain

Answer 9

The visual cortex

Question 10

Where is the visual cortex

Answer 10

In the occipital lobe of the brain, with the visual cortex spanning both hemispheres and the fields lateralised

Question 11

How does the visual cortex work

Answer 11

It has several areas, processing different kinds of visual information, such as colour, shape or movement.

Question 12

Where does visual processing actually start

Answer 12

At the back of the retina, where photoreceptor cells detect light and nerve impulses are sent from the retina to the brain via the optic nerve. Some of these travel to areas of the brain involved in circadian rhythms, but most terminate at the thalamus, which acts as a relay station for the visual cortex

Question 13

What is the auditory centre of the brain

Answer 13

The auditory cortex

Question 14

Where is the auditory cortex

Answer 14

It lies in the temportal lobes on both sides of the brain

Question 15

What is the pathway for auditory information

Answer 15

-Starts in the cochleas, where sound waves are converted to nerve impulses, which travel to the brainstem by the auditory nerve
-In the brainstem, basic decoding takes place, for example the duration and intensity of a sound
-Then information reaches the thalamus, which acts as a relay station and carries out further processing of auditory stimulus
-Finally signals arrive at the auditory cortex. At this stage sound is largely decoded, so the signals are recognized so a response can be given

Question 16

What are the language centres of the brain

Answer 16

Broca’s area and Wernicke’s area

Question 17

What was Broca’s big case study

Answer 17

Tan, who could only express the syllable Tan. Tan could understand spoken language but couldn’t speak or even express thoughts in writing.

Question 18

Outside of Tan, who did Broca study

Answer 18

Eight patients, all of whom had similar languge deficits to Tan, along with lesions in their left frontal hemisphere. Those with damage to these areas in the right hemisphere did not have language problems

Question 19

Where is Broca’s area

Answer 19

In the posterior portion of the frontal lobe of the left hemisphere

Question 20

What have neuroscientists recently found Broca’s area does

Answer 20

Neuroscientists have found evidence of activity in Broca’s area when people perform cognitive tasks that have nothing to do with language. Fredorenko et al discovered two regions of Broca’s area, one selectively involved in language, the other involved in responding to demanding cognitive tasks like maths problems

Question 21

Who found evidence that Broca’s area does more than just language

Answer 21

Fedorenko et al

Question 22

Who discovered an area of the brain invloved in understanding language

Answer 22

Carl Wernicke

Question 23

Where is Wernicke’s area

Answer 23

In the posterior portion of the left temporal lobe

Question 24

How did wernicke discover his area

Answer 24

Those with a legion in the posterior portion of the left temporal lobe were able to speak but not understand language

Question 25

How did Wernicke propose that language works

Answer 25

It involved seperate motor and sensory regions in different corticol regions. The motor region, in Broca’s area, is close to the area controlling the mouth, tounge and vocal cords. The sensory region, in Wernicke’s area, is close to the area of the brain responsible for auditory and visual input. Input from these regions is transferred to Wernicke’s area where it is recognised as language and associated with meaning

Question 26

What neural loop runs between Broca’s and Wernicke’s area

Answer 26

The arcuate fasciculus

Question 27

What areas are Broca’s area near

Answer 27

Areas controlling the mouth, tounge and vocal cords

Question 28

What areas are Wernicke’s area near

Answer 28

Those responsible for auditory and visual input

Question 29

How are Broca’s and Wernicke’s areas connected

Answer 29

Through a neural loop called the Arcuate Fasciculus

Question 30

How have studies into aphasia supported the existance of Broca and Wernicke’s area

Answer 30

It has been discovered that damage to Broca and Wernicke’s areas cause different types of aphasia. Expressive aphasia is an impaired ability to produce language, and in most cases is caused by damage to Broca’s area. Receptive aphasia is an inability to extract meaning from spoken or written words, usually the result of damage to Wernicke’s area.

Question 31

What are the different types of Aphasia

Answer 31

-Expressive aphasia is an impaired ability to produce language, associated with damage to Broca’s area
-Receptive aphasia is an inability to extract meaning from spoken or written words, associated with damage to Wernicke’s area

Question 32

Describe how individual differences can affect localisation of function

Answer 32

Pattern of activation observed in response to various language activities can vary between individuals Bavelier et al found considerable variability in the patterns of activation across different individuals whilst reading, seeing activity in the right temporal, left frontal, temporal and occipital lobes. (Add gender differences)

Question 33

What research has found differences in sizes of brain areas between men and women

Answer 33

Harasty et al found that women have proportionately larger Broca’s and Wernicke’s areas than men. These anatomical differences may explain the superior language skills often found in females

Question 34

Who found different patterns of brain activation can be found between different individuals when reading

Answer 34

Bavelier et al

Question 35

Who found gender differences in the size of Broca and Wernicke’s areas

Answer 35

Harasty

Question 36

Why is it possible that language function is not confined to Broca’s area alone

Answer 36

Dronkers et al re-examined the preserved brains of Tan and Lelong (two of Broca’s patients), and used MRI imaging to identify the extent of any lesions in more detail. They revealed that other areas besides Broca’s area could have contributed to impaired speech.

Question 37

Why are Dronker’s findings particularly important

Answer 37

Because lesions to Broca’s area alone can cause temporary speech disruption, but they don’t usually result in severe disruption of spoken language. Their work overall suggests the brain is more complicated than localised function, involving brain regions rather than localised areas

Question 38

Who MRI’d up Tan and Lelong’s brain

Answer 38

Dronkers

Question 39

Why does equipotentiality threaten a view of localisation

Answer 39

Put forward by Lashley who believed that basic motor and sensory functions were localized, but that higher mental functions were not. He claimed that intact areas of the brain could take over responsibility for specific cognitive functions if there was an injury. According to this point of view, effects of brain damage would be determined by extent rather than location of damage. This view has been supported by the discovery of brain plasticity

Question 40

Who suggested the view of equipotentiality

Answer 40

Lashley