Core study 20- Maguire (B)

Question 1

Background

Where is the hippocampus in the brain?

Answer 1

In the limbic system (the emotional part of the brain)

Question 2

Background

What does the hippocampus play an important part in?

Answer 2

The creation of memories especially, spatial memory and navigation

Question 3

Background

What is the ‘knowledge’?

Answer 3

Black cab drivers required to have a detailed knowledge of the 25,000 streets within a six mile radius of Charing Cross

Question 4

Background

What does the ‘knowledge’ consist of?

Answer 4

A written test on the first 80 routes, then an interview on the other 20 routes

Question 5

Aim

What are the three aims of Maguire’s study?

Answer 5

1. Show that the hippocampus in the human brain structure associates with spatial memory and navigation
2. Examine direct affect of spatial experience of brain structure (plasticty)
3. See if there’s a correlation between length of time as a taxi driver and hippocampal volume

Question 6

Sample

How many taxi drivers were used in the study?

How were they matched?

Answer 6

16

All male, right handed, mean age 44, mean taxi career 14.3 years

Question 7

Sample

How many non-taxi drivers were in the control group?

How were they matched?

Answer 7

50

Health, handedness, sex, mean age

Question 8

Method

What kind of experiment was Maguire’s study?

Answer 8

Lab (quasi) experiment

Status of drivers were naturally occurring

Question 9

Method

What was the IV?

Answer 9

Whether participant was a taxi driver or not

Question 10

Method

What was the DV?

How was it measured?

Answer 10

Volume of hippocampi including their anterior, body and posterior

MRI scans using VBM and pixel counting

Question 11

Procedure

What did Maguire do in order to look at brain structure?

Answer 11

Carried out MRI scans on all participants

Question 12

Procedure

How were the MRI scans assessed?

Answer 12

• VBM
• Pixel counting

Question 13

Procedure

What is VBM briefly?

Answer 13

Eliminates overall brain size to identify differences in grey matter density in different regions of the brain

Question 14

Procedure

What is pixel counting briefly?

Answer 14

Compared the volume of anterior and posterior cross-sections of taxi drivers’ hippocampi with the non taxi drivers

Question 15

Procedure

How was observer bias reduced?

Answer 15

Analysed by one experienced person, who was blinded to VBM results and driver status

Question 16

Results- VBM

Where did volume increase in the taxi drivers’ hippocampi?

Answer 16

In the right and left posterior hippocampi (the back end)

Question 17

Results- VBM

Where did the volume increase for non-taxi drivers?

Answer 17

In the right and left anterior hippocampi (the front)

Question 18

Results- Pixel counting

Which group had greater posterier hippocampal volume?

Answer 18

Taxi drivers

Question 19

Results- Pixel counting

Which group had greater anterior hippocampal volume?

Answer 19

Non taxi drivers (control group)

Question 20

Results

What type of correlation was shown to be present?

Answer 20

There was a significant positive correlation between length of time as a taxi driver and volume of posterior hippocampus

Question 21

Conclusions

What is the hippocampus responsible for?

Answer 21

Navigational memory in humans

Question 22

Conclusions

What can environmental stimulus change?

Answer 22

Volume of the hippocampus- right posterior is linked to navigation

Question 23

GREEDUM

How can generalisability be argued as a weakness?

Answer 23

16 taxi drivers were all male (androcentric), right handed and matched on age ranges

Question 24

GREEDUM

How can reliability be argued as a strength?

Answer 24

16 taxi and 50 non-taxi all had brain scan using same MRI to show physical brain structure and grey matter density

Question 25

GREEDUM

How can data be argued as a weakness?

Answer 25

Positive correlation- quant data doesn’t help show cause and effect

Question 26

GREEDUM

How can ecological validity be argued as a strength?

Answer 26

MRI scans carried out and analysed using VBM and pixel counting- true to real life