Localisation of Brain Function
What is localisation of brain function?
- Specific behaviours and functions e.g. memory, executive control, are associated with specific regions of the brain e.g. the hippocampus, the pre-frontal cortex (PFC)
- Localisation of function (LOF) assumes that there is a biological basis to behaviour and that thoughts, actions and other behaviours are linked to a biological function
- LOF can be measured using techniques to study the brain such as MRI, fMRI and PET
What are some examples of LOF?
- Language production is located in Broca’s area in the left hemisphere of the brain
- Both declarative memory and spatial navigation have been linked to the hippocampus
- Executive control (e.g. impulse control, the ability to plan and to understand consequences) which is a higher-order cognitive function has been linked to the prefrontal cortex
The brain is more like a department store than a specialist shop.
Which research studies support LOF?
- Corkin (1997) used MRI to measure the brain of HM: HM’s hippocampus was almost completely destroyed in his previous surgery so the ability to form new memories can be localised to the hippocampus
- Maguire (2000) used MRI to measure the volume of grey matter in taxi drivers’ brains and found that the left posterior hippocampus was increased in size, thus this region may be localised to spatial navigation
- Raine et al. (1997) used PET scans to demonstrate the lack of activity in the PFC of impulsive murderers which highlights a link between the PFC and executive control
These studies are available as separate Key Studies – just navigate the Brain and Behaviour section of this topic to find them.
Exam Tip
When you are writing a biological approach exam answer make sure that you are using a) sufficient terminology and b) the correct terminology. It is a good idea to ensure that you are 100% confident in naming the regions of the brain and brain structures. If you refer to the hypothalamus when you mean the hippocampus you will miss out on precious marks in your exam: the hippocampus features a lot throughout the theories and studies you will have revised so don’t use the wrong term!
HM and his brain: quite a big deal in Psychology…
Evaluation of LOF research:
- Corkin (1997)
- Strength: The longitudinal nature of this research provided valuable insight into the importance of the hippocampus in relation to memory
- Limitation: This was a case study of one participant, so the results are not easily generalisable
- Maguire (2000)
- Strength: The additional use of correlational analysis (time as a taxi driver and volume of hippocampal grey matter) gave extra support to the idea that spatial navigation is linked to the posterior hippocampus
- Limitation: It is not clear as to whether the participants had pre-existing high levels of posterior hippocampal grey matter before the study commenced
- Raine et al. (1997)
- Strength: The use of a matched pairs design means that individual differences are to some extent controlled for
- Limitation: The findings may be interpreted as being deterministic i.e. lack of PFC functioning means that an individual is destined to be a violent criminal
Worked example
Evaluate research into localisation of function. [22]
Here is part of a response to the above essay question:
One strength of Maguire’s study is that controls were put in place e.g. using only right-handed males. This was done to ensure that the confounding variable of handedness did not impact the validity of the study (handedness may have some effect on the size of certain brain regions like the hippocampi).
One limitation of this study is that the sample is biased as it consisted of only 16 males who lived in or near central London. The findings cannot be generalised to women, left-handed males or taxi drivers from other parts of the UK. The sample size is small which also impacts the generalisability of the findings, but this was due probably to the time and cost-intensive procedure and equipment used in the study.