Localisation of function in the brain

Question 1

What did Broca & Wernicke discover in the 19th century?

Answer 1

Specific areas of the brain are associated with particular physical and psychological functions

Question 2

What was the holistic theory of the brain that scientists generally supported before investigations?

Answer 2

All parts of the brain were involved in processing of thought and action

Question 3

What did Broca & Wernicke argue?

Answer 3

The idea that different parts of the brain perform different tasks involved with different parts of the body

Question 4

What are the 2 hemispheres of the brain?

Answer 4

Right & left hemisphere

Question 5

What is lateralisation?

Answer 5

Our physical & psychological functions are dominated by a particular hemisphere

Question 6

What is the corpus callosum?

Answer 6

Large bundle of more than 200 million nerve fibers that connects the 2 hemispheres & permits communication between them

Question 7

What does the right & left hemisphere generally control?

Answer 7

• Right controls left side of the body
• Left controls right side of the body

Question 8

What is the cerebral cortex?

Answer 8

Outer layer of both hemispheres and is what separates us from animals since it’s more developed in humans

Question 9

What are the 4 lobes of the cortex of the hemispheres?

Answer 9

Frontal, parietal, occipital & temporal

Question 10

What is the frontal lobe?

Answer 10

• back of frontal lobe is motor area
• controls voluntary movements
• location for awareness of what we’re doing within the environment

Question 11

What is the parietal lobe?

Answer 11

• front of both parietal lobes is somatosensory area
• amount of somatosensory area devoted to body part denotes its sensitivity
• location for sensory & motor movements

Question 12

What is the occipital lobe?

Answer 12

• visual area
• location for vision

Question 13

What is the temporal lobe?

Answer 13

• auditory area which analyses speech-based info
• location for memory & auditory ability

Question 14

What is restricted in only the left hemisphere of the brain?

Answer 14

Language

Question 15

What did Paul Broca identify in the 1880s?

Answer 15

A small area in the left frontal lobe is responsible for speech production

Question 16

What causes Broca’s aphasia?

Answer 16

Damage to Broca’s area which results in slow speech that lacks fluency

Question 17

What was Wernicke identifying in patients?

Answer 17

They had no trouble producing language but had difficulty understanding it - speech was fluent but meaningless

Question 18

What did Wernicke identify?

Answer 18

A region in the left frontal lobe that is responsible for language comprehension

Question 19

What is Wernicke’s aphasia?

Answer 19

Damage to Wernicke’s area that results in patients producing nonsense words (neologisms) as part of their speech

Question 20

Evaluation: Brain scan evidence of localisation

Answer 20

• supports localisation theory
• Petersen et al used brain scans to demonstrate how Wernicke’s area was active during listening task & Broca’s area active during reading task
• large no. of sophisticated methods to study brain activity provide scientific evidence for localisation theory

Question 21

Evaluation: Neurosurgical evidence

Answer 21

• neurosurgery first developed in 1950s and still used today for extreme cases of OCD & depression
• Dougherty et al reported on 44 people who had undergone cingulotomy - after 32 weeks at post-surgical follow up a third had met criteria for successful response to the surgery
  -success of these procedures suggest symptoms & behaviours associated with serious mental disorders are localised

Question 22

Evaluation: Case study evidence

Answer 22

• Phineas Gage case of neurological damage supports localisation theory
• but it is difficult to make meaningful generalisations from findings of a single individual
• conclusions drawn may depend on subjective interpretations of the researcher

Question 23

Evaluation: Language localisation questioned

Answer 23

• lang may not be localised to Broca & Wernicke’s area
• review by Anthony & Pascale in 2016 found that only 2% of modern researchers think that lang in the brain is completely controlled by Broca & Wernicke’s area
• fMRI scans allow brain to be studied with more clarity
• language streams have been identified across cortex & thalamus
• localisation theory is contradicted