localisation of function Flashcards
what is the holistic theory
the idea that all parts of the brain were involved in processing thought and action.
what is localisation (localisation of function)
the theory that specific areas of the brain are associated with particular physical and psychological functions
what is lateralisation
the dominance of one hemisphere of the brain for particular physical and psychological functions- speech is lateralised in the left hemisphere
what are the functions of the left + right hemispheres
Left:
- analytic thought
- logic
- language
- science + math
Right:
- holistic thought
- intuition
- creativity
- art + music
what connects the 2 hemispheres
corpus callosum
What is Broca’s area
- responsible for converting thought into speech
- speech production
- damage to this area would result in aphasia - inability (or impaired ability) to understand or produce speech.
- located in the motor area in the left frontal lobe
What is Wernicke’s area
- plays an important role in understanding other people’s speech + for producing speech which makes sense
- language comprehension
- damage to this area would result in aphasia - inability (or impaired ability) to understand or produce speech.
- located in the auditory area in the temporal lobes
what are the 4 lobes + the 2 other parts of the brain you need to know
- parietal lobe
- occipital lobe
- frontal lobe
- temporal lobe
- cerebellum
- corpus callosum connects the 2 hemispheres
what are the 4 areas of the brain you need to know
- somatosensory area
- motor area
- auditory area
- visual area
what is the somatosensory area
- located in the parietal lobes
- where sensory information from the skin, heat, pressure, touch etc is localised
- the amount of somatosensory area developed to a particular body part is directly proportional
- (receptors for hands + face occupy over half this area)
what is the motor area
- located in frontal lobes
- controls voluntary movement in the opposite side of the body –> e.g. left side controls right hand
- damage to this area results in the loss of fine motor skills
- Broca’s area is located in the left frontal lobe
what is the auditory area
- located in temporal lobes
- analyses speech based information
- damage to the area may cause hearing loss
- Wernicke’s area is located here
what is the visual area
- in the occipital lobe (back of brain)
- information is inverted –> so the left eye sends information to the right occipital lobe + the right eye sends information to the left occipital lobe
- damage to the right occipital lobe could mean vision loss in the left eye
what are the +ve AO3 points for localisation of function
- brain scan evidence
- neurosurgical evidence
- Phineas Gage
expand on the +ve AO3 point: brain scan evidence
- MRI scans produce fantastic spatial resolution and provide direct and conclusive evidence for localisation of function
- Tulving showed that different types of LTM were located in different parts of the prefrontal cortex.
expand on the +ve AO3 point: neurosurgical evidence
This is by far the most extreme treatment as it involves the destruction of healthy brain tissue:
- Lobotomy: removal of the brain tissue
- Leucotomy: cutting the connections to a particular part of the brain
- Controversially, neurosurgery is still used today for treatment-in severe depressives and extreme cases of OCD.
- The success of these procedures strongly suggests that symptoms and behaviours associated with serious mental disorders are localised.
- Shows direct support for the theory
expand on the +ve AO3 point: Phineas Gage
- Case study evidence
- This case study clearly demonstrates that certain brain functions are localised - the damage he sustained to his frontal lobe entirely changed his personality and mood. (impatient + rude) → frontal lobe disorder
- He survived an accident in which a large iron was driven completely through his head
- He died after a series of seizures
- Reconstructed his brain, to help learning
what are the -ve AO3 points for localisation of function
- Lashley
- Plasticity
expand on the -ve AO3 point: Lashley
- Not all researchers agree with the view that cognitive functions are localised in the brain.
- The work of Lashley (1950) suggested that basic motor and sensory functions were localised, but that higher mental functions were not.
- Lashley, through experimenting on rats learning to run a maze, found that learning was not localised but involved the whole brain - supporting the HOLISITC view of brain function.
expand on the -ve AO3 point: Plasticity
- One implication of Lashley’s findings is that, the effects of damage to the brain would be determined by the extent rather than the location of the damage.
- This view has received much support over the last 70 years from the discovery that humans are able to regain some of their cognitive abilities following damage to specific areas of the brain.
- This plasticity shows that localisation can be overcome.
