1. E.A. Maguire, K. Wollett & H.J. Spiers
London Taxi Drivers and Bus Drivers: A Structural MRI and Neuropsychological Analysis
E.A. Maguire, K. Wollett & H.J. Spiers

2. Taxi VS Bus

3. Background Taxi Drivers “The Knowledge” 2-4 yr training
25,000 streets!
Bus drivers
Approx. 6 weeks of training
Drive ~12 set routes

5. MRI taxi drivers (Maguire et. al. 2000)
MRI shows
↑ gray matter volume in p. hippocampus
↓ gray matter volume in a. hippocampus
↑ yrs driving taxi ↑ p. hippocampus & ↓ a. hippocampus!

6. MRI of Hippocampus (Maguire et. al. 2000)

7. Current Study: Is hippocampal ∆ really from spatial learning?
Driving around London requires:
Vigilance
Attention
Motor planning
Execution
Stress
May have impact on hippocampal gray matter?!
Is “The Knowledge” acquired at some expense?

8. Enter the Bus drivers! Taxi vs. Bus drivers
To “control” for self-motivation, driving experience & stress on gray matter volume
Taxi
Free movement
Bus
Set route

9. Who?
18 Taxi drivers
17 Bus drivers

10. Neuropsychological Tests
Assessed
Basic cognitive memory
Working memory
Attention
Digit span (7 +/- 2)
Stress
Recognition
London land mark test
In London (yes/no) & which landmark closer

11. Perceived stress scale example
1. In the last month, how often have you been upset because of something that happened unexpectedly?
 ___0=never ___1=almost never ___2=sometimes ___3=fairly often ___4=very often 2. In the last month, how often have you felt that you were unable to control the important things in your life?
 ___0=never ___1=almost never ___2=sometimes ___3=fairly often ___4=very often
3. In the last month, how often have you felt nervous and "stressed"?
___0=never ___1=almost never ___2=sometimes ___3=fairly often ___4=very often
4. In the last month, how often have you felt confident about your ability to handle your personal problems?
5. In the last month, how often have you felt that things were going your way?
From:

12. Procedure Tested individually One 2hr session
MRI & neuropsychological assessment in random order
2 taxi drivers quit (claustrophobia in MRI)

15. Results Taxi drivers compared to Bus drivers
Greater gray matter volume in right/left mid-posterior hippocampi
Less volume in anterior head of right/left hippocampi
NO difference in Caudate Nucleus (learning & memory)

16. mpHippocampus
Coronal
Sagittal
Axial

17. Neuropsychological Tests

18. Neuropsychological Tests cont.

20. No difference in Stress/Anxiety
Not the reason for ∆ in Hippocampal size!

21. Taxi driving exp. on volume

22. Discussion This study confirms 2000 study
“The Knowledge” comes with a price 
↓acquiring/retrieving new visuo-spatial info
∆’s not due to stress

23. Discussion cont. “The Knowledge” becomes sharper with time
↑Yrs driving taxi, ↑ p. hippocampi volume
Similar with musicians, jugglers & bilinguals
Costs/Benefits?
Evolutionarily?
Beyond London?

24. Thank you