Maguire was inspired by previous research that had been done, specifically by Blakemore and Cooper about functional brain plasticity, however, she wanted to expand on this and research structural brain plasticity.
She wanted to investigate the hippocampus, which is a major part of the limbic system in charge of navigation.
Previous research had suggested that the hippocampi of some animals grows in size during times when their navigational and special reasoning skills are exercised more often.
However, there had been no research illustrating whether human brains would plasticise as a result of environmental changes, therefore, Maguire wanted to investigate this further and the best people to use were London Taxi Driver as they had to learn 'The Knowledge' of London and had much navigational experience.
-> VBM (automatic procedure that 'normalises' the scans to a template to eliminate overall brain size as a variable) = brains of 16 taxi driver was compare to 16 non taxi drivers to see if there was a difference in structure
-> pixel counting compared vol of anterior, body + posterior cross-sections of taxi drivers hippocampus
images were analysed by one person (low concurrent validity/inter-rater) experienced in technique + objective analysis = allows total hippocampal volume to be calculated
Biological psychologists suggest that although behaviour had a physiological origin and genetic information is inherited, the environment an individual is in can alter how genetics are demonstrated (1).
Maguire's study examined structural brain plasticity in London taxi-drivers vs non-taxi drivers, and found that taxi drivers had significantly greater grey matter volume in their posterior hippocampus (responsible for spatial navigation of routes already visited) in comparison to controls (1).
Maguire thereforelinks to the biological approach as she explores the innate brain region of the hippocampus, which is part of everyone's physiology; yet the way in which the volume of this region of the brain plasticises is due to the environmental experiences we have e.g. taxi drivers have vast navigational experience of London, leading to increased volume in this region(2)
She found that the volume of the posterior hippocampi of the taxi drivers was larger than the control group, linking to thekey theme of brain plasticity as this clearly illustrates that structural brain plasticity can occur based on environmental navigational experience
- unsure of the brain plasticity of female taxi drivers
- not typical of general population + brain plasticity = everyone's brain may not respond in the same way to the environment demands of doing 'the knowledge
-> matched on key characteristics that could affect the hippocampus eg. age, gender
-> removes individual differences
+ correlational analysis to establish relationship between volume of grey matter
-> cannot confirm cause
- Risk of individual differences as cannot randomly allocate p's to conditions due to naturallyoccurring IV -> IQ and navigational experience could impact volume of hippocampus instead of whether they are a taxi driver
-> how nature + nurture elements interact to cause brain plasticity
-> enhances our understanding of how environment can alter how our innate biological factors change over time, encouraging practical applications such as using structures of the brain that you wish to exercise
- interactionist:
-> didn't only focus on role of innate hippocampus in humans = looked at how environment led to changes in structure of the brain
->focuses on how physiology can change + grow by comparing 2 different groups of men with different navigational experience = volume of hippocampus can pre-determinenavigational experience
Holism:
-> innate size of hippocampal when interacted with environment/navigational experience, the volume can increase + structural plasticity can occur