Maguire

Question 1

Background Research

Answer 1

Lee shown that hippocampal volumes in birds/small mammals
enlarge during seasons where demand for spatial ability is greatest

Maguire wanted to see whether the human brain responds to experiences requiring spatial memory is the same way as birds/small mammals

Question 2

Define
1) Brain plasticity
2) Spatial memory
3) Hippocampus

Answer 2

1) brains tendency to change and adapt as a result of experience and new learning

2) form of memory that allows us to navigate though an environment and remember locations

3) plays a role in memories and spatial memory

Question 3

Aim of Maguire

Answer 3

To investigate whether there is a difference in hippocampal volume between taxi drivers and other people

Question 4

Research method of Maguire

Answer 4

Quasi experiment

IV - whether the participant was a London taxi driver or not was naturally varying + not manipulated by researchers

DV - volume of hippocampi measured by analysing MRI scans using VBM and pixel counting

Question 5

Experimental design of Maguire

Answer 5

Matched-participants design
= matched for health, handedness, sex, mean age and age range

Question 6

Sample of Maguire

Answer 6

16 taxi drivers
all healthy, right-handed, male London taxi drivers with a mean age of 44 and mean time as licensed London taxi driver for 14.3yrs

Control group did not drive taxis (50 for VBM, 16 for pixel counting) matched for all characteristics

Question 7

Why did Maguire use taxi drivers

Answer 7

London taxi drivers must have spatial and navigational infro (pass The Knowledge Test) on city of London to get taxi drivers licence

Maguire could then examine the direct effect of spatial experience of brain structure

Question 8

Procedure of Maguire

Answer 8

used an MRI scanner to calculate the amount of grey matter in the brains of taxi drivers and set of control participants

VBM was used to calculate the volume of grey matter in specific regions of the brain to be measured precisely (3D measure 1.5x1.5x1.5mm)

Pixel counting was used to measure the volume of anterior + posterior hippocampi (2D measure)
> maguire counted no. of pixels in hippocampus then converted this into volume

The images were analysed by one person experienced in this technique and blinded to whether the scan belonged to taxi-driver or non-taxi driver

Question 9

Difference between anterior and posterior hippocampus

Answer 9

Posterior = previously learned spatial information (memory of roads)

Anterior = more involved in learning of new spatial information

Question 10

Results of Maguire

Answer 10

Posterior hippocampi volume of taxi drivers was significantly larger than control participants

Posterior hippocampi volume was positively correlated with amount of time spent taxi driving

Controls had significantly greater anterior hippocampal volume than taxi drivers

Question 11

Conclusions of Maguire

Answer 11

There are structural differences between hippocampus of licensed London taxi drivers compared to those who aren’t

Taxi drivers navigational skills are associated with a distribution of grey matter in the hippocampus

Question 12

Generalisability of Maguire

Answer 12

range of taxi drivers in terms of age and length of licence
> generalisable

only male and right-handed taxi drivers
> can’t generalise to females + left-handed taxi drivers

Question 13

Reliability of Maguire

Answer 13

all participants had MRI scans + standardised techniques used to analyse scans
> VBM + pixel counting were standardised techniques to measure hippocampal volume

same experienced research counted pixels on all scans
> consistency in way hippocampal volume was measured > more replicable and reliable

Question 14

Applications of Maguire

Answer 14

Rehabilitate people with brain damage
> suggests brain can change in response to enviroment

Question 15

Validity of Maguire

Answer 15

NO EXPERIMENTER BIAS
= research analysing scan was blind to each participants condition (taxi vs non-taxi)

GOOD VALIDITY
= participants watched on age and right-handedness
= reduced participant variables affecting results
= can be sure its hippocampal volume is affected by taxi driver or not

Question 16

Ethics of Maguire

Answer 16

INFORMED CONSENT
= MRI scans are powerful magnetic field so had to ask if taxi drivers had mental implants eg. pacemakers
= some people find MRI scanners claustrophobic

Question 17

Type of data in Maguire

Answer 17

QUANTITATIVE DATA
= measurement of volume of hippocampus

Strength as it can be statistically analysed + objective
= the hippocampal volume of taxi-drivers could be easily compared against those of non-taxi drivers

Question 18

Maguire and biological area

Answer 18

biological area looks at how biological factors affect our behaviour eg. genes, brain structure, neurons

Maguire looked at brains of taxi drivers + compared to non-taxi drivers using MRI scans

Found taxi drivers who pass Knowledge test have greater posterior hippocampal volume

Study shows how brain structure, a biological factor) can affect our behaviour eg. navigational skills

Question 19

Maguire and key theme ‘brain plasticity’

Answer 19

found taxi drivers brain can change in relation to their job as they have to understand and learn routes around London

specifically, posterior hippocampal volume gets bigger

Question 20

Maguire and Nature/Nurture Debate (interactionist view)

Answer 20

considers both nature + nurture

nurture
= brain adapts to out environment
= vol of grey matter in posterior hippocampus was greater in taxi drivers as it stores info about spatial memory
= vol of posterior hippocampus increases with length of time in job

nature
= certain brain structures eg. anterior + posterior hippocampi have particular functions determined by our biology

Question 21

Two controls in Maguire

Answer 21

1) only use male right-handed participants for both taxi/non-taxi drivers to control participant variables

2) same researcher measured hippocampal volume using VBM

Question 22

Evaluate usefulness of providing biological explanation for behaviour

Answer 22

Biological explanations are useful as they help us understand how biological factors eg, brain structures affect behaviour and lead to medical treatments

Maguire showed how hippocampus changed in taxi drivers vs non taxi drivers

useful as showed brain plasticity + can be used to rehabilitate people with brain damage

Not useful as biological explanations don’t consider how environmental factors affect behaviour

on other hand, Maguire did

Question 23

to what extent does maguire change our understand of key theme

Answer 23

changes understanding of brain plasticity as it looked at humans whereas B&C looked at animals only

B&C looked at visual cortex of kittens changed as result to exposure of only H or V lines

Maguire looked at posterior hippocampal volume had increase in taxi drivers vs non. as result to navigational skills

Question 24

To what extent does Maguire change understanding of individual, cultural and social diversity

Answer 24

INDIVIDUAL
= Maguire showed this in hippocampal volumes as taxi drivers with navigation skills cause grey matter in hippocampus to redistribute so there is more in posterior hippocampus

SOCAIL
= only used males so no
= showed improvements in measuring brain activity for future research

CULTURAL
= london taxi drivers
= could be cultural differences in brain plasticity