Localisation of Brain Function (DP IB Psychology)

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.

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