Localisation of function

Question 1

Localisation of function

Answer 1

specific areas of the brain (lobes) are associated with specific physical and psychological functions

Question 2

4 lobes of the brain

Answer 2

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

Question 3

Frontal lobe

Answer 3

• motor area - responsible for movements e.g walking
• damage = loss of control over movements
• stores mental processing e.g. thinking and cognition
• stores personality traits and characteristics
• e.g. Broca’s area - Broca identified left frontal cortex is responsible for speech production , damage to this = Broca’s aphasia , slow and lack of speech production

Question 4

Temporal lobe

Answer 4

• consists of auditory area
• damage to this may lead to hearing loss
• e.g. Wernicke’s area- Wernicke identified that left temporal lobe is reponsible for understanding speech, damage = Wernicke’s aphasia, person cant comprehend the content of speech

Question 5

Occipital lobe

Answer 5

• consists of the visual cortex
• info from right visual field is sent to the left visual cortex
• info from left visual field id sent to the right visual cortex
• concept applies to entire body

Question 6

Parietal lobe

Answer 6

• consists of somatosensory area which is seperated from motor area by central sulcus
• sensory information from the skin is stored e.g. touching heat

Question 7

Cerebellum

Answer 7

• concerned with balance and coordination
• activities are carried out automatically e.g. walking and running

Question 8

Evaluation

Answer 8

+ Phineas Gage
+ Petersen et al
+ Tulving et al
+ Practical application: Lobotomoy
- Lashey
- Lashey’s law of equipotentiality

Question 9

+ Case study of Phineas Gage

Answer 9

• 25 years old
• 1848 tamping iron went through skull, taking part of the frontal lobe in brain with it
• damage had impact on his personality
• went from calm abd reserved to rude and quick tempered
• suggests that brain is localised as frontal lobe is responsible for personality because the frontal lobe is responsible for personality

Question 10

Brain scan evidence

Answer 10

• Petersen et al
• Tulving et al

Question 11

+ Petersen et al

Answer 11

• 1988
• used brain scans to demonstrate how Wernicke’s are was active during listening task and Broca’s are was active during a reading task
• suggests that different areas of brain have different functions
• evidence for localisation of function

Question 12

+ Tulving et al

Answer 12

• 1994
• used PET scanner
• revealed that semantic and episodic memories reside in different parts of pre-frontal cortex
• left-prefrontal cortex was involved in recalling semantic memories
• right-prefrontal cortex involved in recalling episodic memories
• evidence of localisation of function

Question 13

+ Practical application: Lobotomy

Answer 13

• discovered by Freeman in the 1950s
• involved destroying connections in the frontal lobe to control aggressive behaviour
• example of neurosurgery - removing or destroying parts of the brain
• neurosurgery is still used in extreme cases of OCD and depression
• Dougherty et al (2002) reported on 44 OCD patients who underwent neurosurgery of the cingulate gyrus (associated with OCD)
• 32 weeks later, 33% of patients met criteria for successful response to procedure and 14% had a partial response
• suggests that brain is localised as part of the brain is responsible for OCD
  - not string procedure as results arent very high and procedure is not common

Question 14

- Lashey’s research

Answer 14

• 1950
• Lashey removed areas of cortex (10-50%) in rats learning maze route
• no area proven to be more significant than other in terms of time taken and ability needed to learn maze
• appeared that process of learning required every part of cortex
• weakness as it suggests that brain functions in a holistic manner and is not localised
  - however, its an animal study as it was tested on rats so it may not be generalised to humans

Question 15

- Law of equipotentiality

Answer 15

• when brain has been damaged through illness/injury and a particular function has been lost, rest of brain is able to reorganise itself in attempt to recover lost function
• surving brain circuits ‘chip in’ so the same neurological action can be achieved, although this doesnt happen all the time
• brain functions in a holistic manner as the parts work together