Localisation of function in the brain

Question 1

What did Broca and Wernicke discover?

Answer 1

• specific areas of the brain are associated with certain physical and psychological functions
• before scientists had a holistic theory of the brain

Question 2

what is localisation of function?

Answer 2

• different parts of the brain perform different tasks and are involved with different parts of the body
• if a certain area becomes damaged the function of that area will also be affected

Question 3

Hemispheres of the brain

Answer 3

• main part of the brain is split into left and right hemispheres
• activity on the left side of the body is controlled by the right hemisphere
• activity on the right side of the body is controlled by the left hemisphere

Question 4

What is lateralisation?

Answer 4

• some of physical and psychological functions are dominated by a particular hemisphere

Question 5

what is the cerebral cortex?

Answer 5

• outer layer of both hemispheres
• its divided into four lobes

Question 6

what are the cortex’s four lobes?

Answer 6

• frontal lobe
• parietal lobe
• occipital lobe
  -temporal lobe

Question 7

what is the motor area?

Answer 7

• at the back of the frontal lobe in both hemispheres
• controls voluntary movement in the opposite side of the body
• damage= loss of control over fine movements

Question 8

what is the somatosensory area?

Answer 8

• at the front of both parietal lobes
• where sensory info from the skin is represented
• the amount of area devoted to a certain body part determines its sensitivity
• receptors on our face and hands take up half our somatosensory area

Question 9

what is the visual area?

Answer 9

• each eye sends info from the right visual field to the left visual cortex and vice versa
• damage to the left hemisphere can produce blindness in both eyes right visual field and vice versa

Question 10

what is the auditory area?

Answer 10

• analyses speech based info
• damage may produce partial hearing loss
• damage to the specific area of the temporal lobe may affect the ability to comprehend language

Question 11

what did Broca find

Answer 11

• language is restricted to the left side of the brain
• Broca identified a small area in the left frontal lobe responsible for speech production

Question 12

Brocas area

Answer 12

• Brocas aphasia which is damage to this area makes speech slow and inconsistent
• Tan had brocas aphasia and could only say ‘tan’
• they have difficulty with conjunctions and pronunciations

Question 13

what did wernicke find ?

Answer 13

• disocvered people who could produce language but couldnt understand it
• what they said was fluent but meaningless

Question 14

Evaluation strength : evidence from neurosurgery

Answer 14

• neurosurgery is the last resort for treating mental disorders
• Dougherty et al. reported 44 people with OCD that had cingulotomy
• after 32 weeks 30% had a successful response and 14% had a partial response

Question 14

wernickes area

Answer 14

• area in the left temporal lobe responsible for language understanding
• wernickes aphasia when this area is damaged
• often produce nonsense words as their speech content

Question 15

Evaluation limitation : counterpoint to brain scans

Answer 15

• Lashley removed areas of the cortex in rats that were learning a maze
• no area was more important than others in rats when learning the routes
• learning required every part of the cortex
• higher cognitive processes aren’t localised but distributed in a holistic way

Question 15

Evaluation strength: evidence from brain scans

Answer 15

• petersen et al. used brain scans to show how wernickes area was active during listening tasks and brocas area was active during reading tasks
• Buckner and petersen reviewed long term memory studies and found semantic and episodic memories resided in different parts of the prefrontal cortex

Question 16

Evaluation limitation: language localisation questioned

Answer 16

• Dick and Tremblay found only 2% of researchers think language is controlled by just broca and wernickes areas
• from MRI’s it was found that language is distributed more holistically
• language streams have been found in the cortex, right hemisphere and subcortical regions e.g. thalamus