London Taxi Drivers and Bus Drivers: A Structural MRI and Neuropsychological Analysis

1. 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? ___0=never ___1=almost never ___2=sometimes ___3=fairly often ___4=very often 5. In the last month, how often have you felt that things were going your way? ___0=never ___1=almost never ___2=sometimes ___3=fairly often ___4=very often From: http://www.macses.ucsf.edu/Research/Psychosocial/notebook/PSS10.html

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

14. http://www.youtube.com/watch?v=7g5UVrOt2CI

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)

17. Neuropsychological Tests

18. Neuropsychological Tests cont.

20. No difference in Stress/Anxiety

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?