Maguire (contemporary study)

Question 1

What part of the brain does this study investigate?

Answer 1

The hippocampi

Question 2

Hippocampi structure

Answer 2

Bilateral (1 for each hemisphere)
Contains a posterior (back), main body and anterior (front)

Question 3

Main function of hippocampi

Answer 3

Helps us to navigate known environments by holding spatial memory of that area

Question 4

2 background research to this study

Answer 4

Migration seasons for birds mean hippocampus volume increases: does it occur in humans if we require more spatial memory?
Differences across various brain structures exist dependent on people with different skills: did brain change in response to environmental changes of learning skill or were they born with this brain thus more predisposed to taking up the skill?

Question 5

Who was chosen to be investigated in this study and why?

Answer 5

London taxi drivers because they have to pass a test called ‘the knowledge’
Memorisation of streets and street names in London: compared to average person their spatial memory demand is higher so we can investigate neuroplasticity within them

Question 6

Aims

Answer 6

Investigate differences in volume of hippocampi London taxi drivers vs not London taxi drivers
Investigate functions of each section of hippocampus
Correlational analysis if there is pos correlation between time spent as taxi driver to volume of hippocampi

Question 7

Sample of taxi drivers

Answer 7

16 men who had passed the knowledge and 1.5 years experience as a driver

Question 8

Sample method for taxi drivers

Answer 8

Self selected from radio adverts and contacting the taxi company

Question 9

Sample of control group (non taxi driver)

Answer 9

50 male MRI profiles from UCL neurology department

Question 10

Sample method for control group

Answer 10

Opportunity: these are MRI scans of men who happened to be scanned

Question 11

Controlling for participant variables

Answer 11

Across each group: all men, all right handed, all had healthy neurological profiles, all aged 32-62

Question 12

What type of experiment is this?

Answer 12

A quasi experiment because the naturally occurring IV is whether someone is a taxi driver and learnt the knowledge compared to someone who is not

Question 13

Experimental design

Answer 13

Independent measures because we cannot manipulate the IV for participants to go through both conditions and be compared against themselves

Question 14

What type of MRI scan was used?

Answer 14

Structural MRI scan

Question 15

Main procedure of the study

Answer 15

Taxi drivers had structural MRI scan and their profiles were compared to MRI scans selected from control group

Question 16

Analysis of MRI scans

Answer 16

Pixel counting
Voxel based morphometry

Question 17

Pixel counting

Answer 17

Counting pixels of a 2D cross sectional area of hippocampus sections

Question 18

voxel based morphometry

Answer 18

3D measurement of volume of grey matter done by computer

Question 19

How were the analysis of hippocampus done and why is that a strength?

Answer 19

Done by researchers blind to who the profile belonged to
This decreases researcher bias as they will provide objective measurements that isn’t affected by their own interpretation thus increases validity

Question 20

Checking for concurrent validity

Answer 20

We use the pixel counting older method to check the results of VBM (new) are consistent, thus an accurate measurement of volumes of hippocampus

Question 21

Results for main procedure analysis of MRI profiles: hippocampus posterior

Answer 21

A significantly higher difference was found in grey matter volume of the posterior hippocampus in taxi drivers compared to the non taxi drivers

Question 22

Results for main procedure analysis of MRI profiles: hippocampus anterior

Answer 22

Significantly smaller in taxi drivers compared to in the control

Question 23

Results for main procedure analysis of MRI profiles: hippocampus body

Answer 23

No difference in hippocampus body volume across the 2 groups

Question 24

What can we conclude from the main procedure?

Answer 24

Differences in volume of the parts of the hippocampus in taxi drivers compared to non taxi drivers: taxi drivers had larger volume in posterior compared to control but a smaller volume of anterior
Body stated constant thus the increase in posterior was offset by decrease in anterior
Differences in function of hippocampus

Question 25

Correlational study purpose

Answer 25

To investigate if there is correlation between volume of the hippocampus parts and time spent as a taxi driver

Question 26

What type of study was the correlational part?

Answer 26

A cross sectional study: type of snapshot study
Where we took a snapshot of the MRI scans of taxi drivers of increasing years of experience and compared them against each other to show a change in years spent as taxi driver (rather than the same person)

Question 27

What did the correlation find?

Answer 27

Positive correlation between time spent as taxi driver and volume of posterior hippocampus volume
Negative correlation between time spent as taxi driver and volume of anterior hippocampus volume

Question 28

Conclusions from correlational analysis

Answer 28

Confirms brain changed in response to environment (longer time spent demanding spatial memory) so shows evidence for brain plasticity
Rather than people born with this structure of hippocampus are predetermined into becoming taxi drivers

Question 29

Differences in function of anterior vs posterior hippocampus

Answer 29

Posterior holds spatial memory of previously learnt areas
Anterior works in learning new spatial memory and navigating unfamiliar environments

Question 30

Small anterior effect on taxi drivers

Answer 30

Have difficulty with spatial memory tasks of new and unfamiliar tasks