Localisation Of Function In The Brain

Question 1

What is localisation of function?

Answer 1

Functions such as movement, speech and memory are performed in distinct regions of the brain

Question 2

What is the opposite view of localisation of the brain?

Answer 2

That the brain acts holistically to perform functions

Question 3

What cortices are on both sides of the brain?

Answer 3

Motor cortex

Somatosensory cortex

Visual cortex

Auditory cortex

Question 4

Where are Broca and Wernicke’s areas in the brain?

Answer 4

Left hemisphere

Question 5

What is hemispheric lateralisation?

Answer 5

Each hemisphere of the brain is specialised to perform different functions

Question 6

What function is performed by the left hemisphere?

Answer 6

Language

Question 7

What tasks are performed by the right hemisphere?

Answer 7

Visuospatial

Question 8

What does contralateral mean?

Answer 8

Each hemisphere of the brain controls the opposite side of the body, including motor and sensory pathways and vision of the opposite side of the body

Question 9

What is cortex?

Answer 9

The surface layer of the brain referred to as grey matter

2-4 mm thick and folded for extra surface area for processing

Question 10

What is white matter in the brain?

Answer 10

Mainly myelinated axons

Question 11

What is the visual cortex?

Answer 11

The brains’ visual processing centre

Each hemisphere’s occipital lobe receives information from the contralateral visual field

Question 12

What happens if the occipital lobe/visual cortex is damaged?

Answer 12

Leads to partial or complete loss of vision called cortical blindness

Damage to one cortex can lead to loss of vision in the opposite visual field

Question 13

Where is the motor cortex?

Answer 13

The back of the frontal lobe

Question 14

Where is the somatosensory cortex?

Answer 14

Front of the parietal

Question 15

How are the motor and somatosensory cortex divided?

Answer 15

By a fold called the central sulcus

Question 16

What is the motor cortex responsible for?

Answer 16

Voluntary motor movements

Contralateral

Question 17

What happens if the motor cortex is damaged?

Answer 17

Loss of muscle function or paralysis (if serious trauma occurs) occurs on the opposite side of the body of hemisphere damaged due to contralaterality

Question 18

What is the somatosensory cortex responsible for?

Answer 18

Receiving sense impressions from around the body

Contralateral

Question 19

What does damage to the somatosensory cortex do?

Answer 19

Loss of sensation, makes it ignore areas of the body, loss of ability of recognising objects by feel

Effects are in opposite side of body (contralateral)

Question 20

What is the function of the auditory cortex?

Answer 20

Receieves and processes sound information from ears

Question 21

Where is the auditory cortex located?

Answer 21

In both hemispheres at the top of the temporal lobe

Question 22

Where is the Broca’s area located?

Answer 22

Left frontal lobe

Question 23

What is Broca’s area responsible for?

Answer 23

Speech production

Question 24

When was the Broca’s area discovered?

Answer 24

After case study and post mortem of Tan

Question 25

What does damage to the Broca's area cause?

Answer 25

Broca's aphasia (aka expressive/motor aphasia) Difficulty producing fluent speech, speech is slow and effortful, missing words and poor grammar

Question 26

Where is Wernicke's area located?

Answer 26

Top temporal lobe

Question 27

What is Wernicke's area responsible for?

Answer 27

Speech comprehension

Question 28

When was Wernicke's area discovered?

Answer 28

After case studies of individuals who could produce fluent sounding speech that made little sense

Question 29

What does damage to Wernicke's area cause?

Answer 29

Wernicke's aphasia (aka receptive/sensory aphasia) Difficulty understanding speech or written language, speech sounds fluent but lacks meaning/nonsense works

Question 30

What is global aspasia?

Answer 30

The inability to produce or understand speech

Question 31

What causes global aspasia?

Answer 31

Damage to both Broca's and Wernicke's area

Question 32

What is an example of case studies being seen as scientific?

Answer 32

Tan's brain had damage covering multiple regions

Question 33

What suggests that the localised/holistic nature of the brain is dependant on the function?

Answer 33

• High connectivity of the brain means no one area is independant • Motor and somatosensory functions are highly localised • Language is more distributed • Consciousness appears not localised at all

Question 34

What clinical case studies suggest functions are localised in certain areas?

Answer 34

• Demonstrate loss of certain functions if damage is caused to particular areas of the brain • Broca and Wernicke's case studies on aphasia • Clive Wearing (amnesia)

Question 35

How do modern brain scanning techniques such as fMRI support older research on lamguage centres?

Answer 35

Show actication in the regions associated when healthy participants perform language tasks

Question 36

What was Lashley's study?

Answer 36

50 rats ran a maze before and after areas of their brain cortex were destroyed

Question 37

What did Lashley find?

Answer 37

Rats' ability to successfully re-run the maze was affected by how much brain cortex was destroyed, not which areas

Question 38

What does Lashley's study suggest?

Answer 38

Higher cognitive processes such as learning and memory are not localised but are distributed across the brain - As the more the brain was destroyed, the worse the function was - Equopotentiality of the cortex was proved as any healthy area of the cortex can perform the memory functions of damaged areas