Localisation of function in the brain

Question 1

AO1- Localisation of function in the brain, broca and wernickes area

Answer 1

• Brocas area is a language centre, named after the french neurosurgeon who treated a patient who he refereed to as ‘ tan’ as this was the only word he could express, he had a unusual disorder as he could process language but not say it out loud
• Broca then studied 8 other patients all with similar language deficits along with lesions in their frontal left hemisphere, patients with this issue in their right hemisphere did not have the same language disorder as the people with the left issue,
• Lead him to identify a language centre in posterior frontal lobe, critical for speech
• Wernickes area was in posterior position of left temporal lobe, patients with a lesion in this area could speak but unable to understand language
• This proposed language involvesseperate motor and sensory regions

Question 2

Limitation to localisation ( equipotentiiality)

Answer 2

NOt all researchers agree with the view that cognitive functions are localised in the brain
- A confliciting view is the equipotentiality thoery ( Lashely 1930) , he believed that basic motor and sensory functions were localised but higher mental functions were not. He claimed that intact areas of the cortex could take over responsibility for specific cognitive functions following injury to the area normally responsible for this function

Question 3

Alternative views than localisation of function

Answer 3

• Research suggests what may be more important is the way different areas of the brain interact with each other, rather than which specific brain areas control a particular cognitive process
• Wernicke suggested alothough differet areas of the brain have different specialised functions they are interdependent in the sense that to work they must interact with each other
• Suggets that complex behaviours such as language reading and movement are built up gradually as a stimulus enters the brain, the moves through different structures before a response is produced

Question 4

Support of localisation of function AO3 Language centres

Answer 4

• Evidence for different functions of Brocas and Wernickes areas in language production and understanding comes from discovery that damage to these different areas result in different types of aphasia
• Expressive aphasia is an impaired ability to produce language, in most cases this is due to damage in Brocas area
• Demonstrates important role played by these brain regions in different aspects of langauge

Question 5

Support of localisation of function A03

Answer 5

Brain scans: fMRI scans demonstrate correlations between different mental activities and different areas of the brain. For example, Ovaysikia et al (2011) demonstrates increased blood flow in different areas of the brain depending on whether a person is reading words or recognising facial expressions.