Maguire et al (2000) Flashcards
Background of the study
-The hippocampus is a region of the brain that is involved in spatial memory
-The volume of the hippocampus is enlarged in animals that have a large territory to navigate
What is grey matter?
-Tissue in the nervous system that appears grey, as it is composed of numerous nerve cell bodies
-This is involved in processing information in the brain
Aim of the study
Maguire wanted to find out whether the hippocampus may also show plasticity among humans
Sample
-Self-selecting
-16 right-handed male London taxi drivers, aged 32-62
-Taxi drivers for at least 18 months since completing ‘the knowledge’
-Had healthy general medical profiles
Procedure (quasi-experimental part of the study)
-Quasi experiment
-Taxi drivers had an MRI scan of their brain, which was compared to the scan of a non-taxi driver
-Analysed by pixel counting and Voxel-Based Morphometry
Participants in the control group
-50 people (only 16 chosen)
-Chosen from scans already on record at the Wellcome institute in London
-Matched on age, being right-handed and being male
-Not taxi drivers
What was pixel counting?
-2D measurement of volume
-Old method of analysis and involved pixels being counted up manually
-Was only done for the hippocampus
What was Voxel-Based Morphometry (VBM)?
-3D measurement of volume
-A new technique done by computer
-Applied to the whole brain
Findings (quasi-experimental part of the study)
-Compared to the control group:
-Taxi drivers had significantly more grey matter in the posterior part of the hippocampus
-Taxi drivers had significantly less grey matter in the anterior part of the hippocampus
Procedure (correlational part of the study)
-MRI scans of the taxi drivers further analyses
-Maguire wanted to see if there was a correlation between length of time as a taxi driver, ad volume of grey matter in the hippocampus
Findings (correlational part of the study)
-Positive correlation between length of time as a taxi driver, and volume of grey matter in posterior part of the hippocampus
-Negative correlation between length of time as a taxi driver, and volume of grey matter in anterior part of the hippocampus
Conclusions
-The Quasi-experimental part of the study confirmed that the right hippocampus has plasticity (this may be true for the rest of the brain but was not relevant to the study)
-The correlational part of the study suggests these changes in the hippocampus can occur in lie with the demands placed on taxi drivers by their job
How does the study link to the nature-nurture debate?
-Nurture
-The taxi drivers weren’t born with that volume of grey matter
-It has changed over the years of them being a taxi driver
How does the study link to the freewill-determinism debate?
-Determinism
-Size of the sections in the hippocampus is determined by the spatial memory needs in a person’s job
How does this study relate to the individual-situational explanations debate?
-Situational
-Brain structure has changed due to the situation of being/not being a taxi driver
How could this study be seen as socially sensitive?
Socially sensitive as they may feel anxious about a deficit they have in learning new things as a result of their job
How does the study link to the nature-nurture debate?
-Nurture
-Weren’t born with that volume of grey matter, it has changed over the years of them being a taxi driver
How does the study link to the freewill-determinism debate?
-Determinism
-Size of the sections in the hippocampus is determined by the spatial memory needs in the persons job
How does the study link to the individual-situational debate?
-Situational
-Brain structure changed due to situation of being/not being a taxi driver
How could the study be seen as socially sensitive?
Socially sensitive as people may feel anxious about a deficit they have in learning new things as a result of their job
How does this study relate to the biological area?
-Behaviour has affected brain structure
-Suggests the ability to navigate different routes and maps is related to a specific region of the brain-the hippocampus
Similarities between Maguire and B&C studies
-Both studies were highly controlled
-Both studies were ethical
Elaborate on both studies being highly controlled
-B&C had many controls-having cats in the striped tubes for the same amount of time
-Maguire gave her students the same MRI scan and analysed the scans the same way
Elaborate on both studies being ethical
-B&C limited harm by only using two kittens
-Maguire’s procedure of an MRI wasn’t harmful and the taxi drivers consented
Differences between Maguire and B&C studies
-Had a different species within their samples
-Collected different types of data
Elaborate having a different species in their samples
-B&C used two kittens to test the visual cortex
-Maguire tested human adults who were taxi drivers, or the control group
Elaborate collecting different types of data
-B&C collected qualitative data by making observation notes on the behaviour of the 5 month old kittens
-Maguire collected quantitative data using VBM and pixel counting to calculate the size of the hippocampus
How it has changed our understanding of the key theme of ‘brain plasticity’
Adds to B&C’s findings in confirming that neuroplasticity can also occur in the brain of the humans (specifically in the hippocampus)
How it hasn’t changed our understanding of the key theme of ‘brain plasticity’
Doesn’t necessarily show that the visual neurons of humans would show the same kind of neuroplasticity (humans exposed to a limited visual environment may not show the same visual deficits as found in the kittens)
How the study has changed our understanding of individual diversity
The MRI scans can allow us to investigate brain plasticity in healthy human participants and reveal individual differences in brain structures as a result of experience
How the study hasn’t changed our understanding of individual diversity
It doesn’t tell us about left handed individuals
How the study hasn’t changed our understanding of social diversity
It doesn’t tell us about female individuals
How the study hasn’t changed our understanding of cultural diversity
Maguire only looked at the brains of London taxi drivers (UK)
