Missing a limitation
Brain scan evidence
Type: Strength
Study: Peterson et al. (1988)
- Used brain scans to show activity in Wernicke’s area during a listening task and in Broca’s area during a reading task
- Suggests these areas of the brain have different functions
- The fact that such sophisticated and objective methods for measuring activity in the brain are linked to specific functions provides scientific evidence of localisation of functions
Neurosurgical evidence
Type: Strength
Study: Dougherty et al. 92002)
- Surgically removing or destroying areas of the brain to control aspects of behaviour was developed in the 1950s
- Study reported on 44 COD patients who had part of their brain tissue removed to treat their OCD
- 1/3 has a successful response
- Supports localisation of mental disorders because when those specific areas of the brain were remove, in some cases, the disorder disappears
Gage
Type: Strength
Case Study: Phineas Cage
- Received serious brain damage in an accident
- A pole went through part of his frontal lobe
- Survived but the damage affected his personality
- Went from calm and reserved to quick-tempered and rude
- Supports localisation theory because it suggests that one specific area of the brain (frontal lobe) is responsible for a specific psychological function (mood)
Neural plasticity
Type: Limitation
- When one part of the brain has become damaged and a function has been lost, the rest of the brain is able to reorganise itself to help recover the function
- Other areas of the brain ‘chip in’ so the same function can be achieved
- Occasionally occurs in stroke victims who regain some of their cognitive abilities following damage to specific areas of the brain
- Limitation because it suggests all parts of the brain work together to enable specific functions, rather than one singular area being responsible
Learning is too complex to be localised
Type: Limitation
Study: Lashley (1950)
- Suggests higher cognitive functions are not localised but distributed in a more holistic way in the brain
- Lashley removed between 10% - 50% in rats learning in a maze
- No single area was more important than any other in terms of the rats’ ability to learn the maze
- Contradicts localisation - suggests that learning is too complex to be localised and involved the whole brain
Could be defended by not being applicable to humans due to the usage of mice.