Flashcards in Maguire - Biological Deck (7):
Results from Maguire's study
•Taxi cab drivers showed significantly more grey matter in both left and right posterior hippocampi compared to the control group
•Controls had more grey matter in the left and right anterior hippocampi
•Taxi drivers had a greater posterior hippocampal in volume
•Controls had greater anterior right hippocampal volume and a greater hippocampal body volume on the right and left.
Correlations showed a significant positive correlation between the length of time as a taxi driver and the right posterior hippocampal volume, but a negative correlation for the anterior hippocampal volume.
Aim of Maguire's study
To investigate whether or not the hippocampus plays a role in human spatial memory and navigation
Evaluation of Maguire's study
• No researcher bias
• No ethical implications
• Only observed males
• Only observed 16 matched pairs
Research method of Maguire's study
•It was a quasi experiment…
•…because the IV (where the participant was a London taxi driver or whether they did not drive a taxi) could not be manipulated.
•The DV was the volume of hippocampi measured by analysing MRI scans
•The design of the study was an independent measures matched pairs design.
16 healthy, right-handed, male, London taxi drivers with a mean age of 44 years old (32-62 years old). Mean time licensed as a London taxi driver was 14.3 years (1.5-42 years).
The 16 out of the 50 in the control group who did not drive taxis were matched for health, handiness, sex, means age and age range.
Outline of procedure
All Ps were scanned at the same unit. The MRI scans of all Ps were analysed using:
i) VBM identifies differences in grey matter density. The brains of the 16 taxi drivers were compared to those of the 50 non taxi drivers to see if there were any differences in structure.
ii) Pixel counting compared the volume of the anterior, body and posterior of the taxi drivers hippocampi with those of a matched sample of 16 controls taken from the 50 used in the VBM analysis. Images were analysed by one person well experienced in the technique and blinded to whether the scans were of taxi or non taxi drivers.