hemispherical lateralisation

Question 1

hemispheric lateralisation

Answer 1

• refers to the notion that certain functions are principally governed by one side of the brain
• two hemispheres connected by corpus callosum (bundle of nerve fibres)
  = work together to form most tasks

Question 2

left hemisphere

Answer 2

• responsible for the RHS of the body
• language centres lateralised to LH
• wider network + Broca’s Area = speech production
• damage to Broca’s Area = expressive aphasia
• Wernicke’s Area = speech comprehension
• damage to Wernicke’s Area = receptive aphasia

Question 3

right hemisphere

Answer 3

• responsible for the LHS of the body
• viso-spatial functions

Question 4

ads of hemispheric lateralisation

Answer 4

• evolutionary perspective
• global aphasia

Question 5

disads of hemispheric laterlisation

Answer 5

• age
• speak RH
• hemisphere compensation

Question 6

evolutionary perspective - ads of hemispheric lateralisation

Answer 6

• it makes sense from an evolutionary perspective
• increases neural capacity = adaptive
• uses one H to engage in a specific task, leaving the other H free to engage in another function
• psych found that H lateralisation in chickens associated w/ an ability to perform 2 tasks simultaneously

Question 7

global aphasia - ads of hemispheric lateralisation

Answer 7

• patients who have extensive damage to their LH
• can experience global aphasia
  = loss of speech production + comprehension
  = suggests that language is lateralised to the LH

Question 8

age - disads of hemispheric lateralisation

Answer 8

• lateralisation patterns shift w/ age
• w/ most tasks generally becoming less lateralised in healthy adulthood

Question 9

speak RH - disads of hemispheric lateralisation

Answer 9

• a split-brain patients developed the capacity to speak using his RH
• they could speak aboout info presented in either the left visual field or right
  = appears that language is not lateralised entirely to the LH

Question 10

hemisphere compensation - disads of hemispheric lateralisation

Answer 10

• if one H is damaged, undamaged regions of the opposite hemisphere can compensate
• psych reported the case of EB who had his entire LH removed due to a tumour
• his language seemed normal in terms of vocab + grammar in every day life
• HOWEVER, systematic testing revealed subtle grammatical problems etc..
• suggests that RH cannot provide by itself a perfect mastery of each component of language