London Taxi vs. Bus Drivers Study Notes

Introduction

• Maguire et al. (2000) found that London taxi drivers had greater posterior hippocampal gray matter volume and reduced anterior hippocampal gray matter volume compared to controls.

• This suggested the hippocampus has plasticity to accommodate spatial representation.

• This study addresses whether self-motion, driving experience, and stress contribute to these structural differences by comparing taxi drivers to bus drivers.

Methods

• Participants: 18 licensed London taxi drivers and 17 London bus drivers matched for driving experience and stress levels.

• MRI Scans: Whole brain structural MRI scans were acquired using a 1.5 T Sonata whole body scanner.

• Neuropsychological Test Battery: Assessed working memory, attention, verbal and visual memory, and recognition of London landmarks.

• Stress and Anxiety Measures: Questionnaires to assess perceived stress, life stress, job stress, and state-trait anxiety.

Results

• Gray Matter Volume: Taxi drivers had greater gray matter volume in mid-posterior hippocampi and less volume in anterior hippocampi compared to bus drivers.

• Neuropsychological Tests: Taxi drivers excelled in London landmark recognition and proximity judgments but were poorer at delayed recall of the Rey-Osterrieth Complex Figure.

• Stress and Anxiety: No significant differences in stress or anxiety levels between the two groups.

• Effect of Experience: Years of taxi driving correlated with increased right posterior hippocampal gray matter volume and decreased anterior hippocampal gray matter volume in taxi drivers.

Discussion

• The study confirms and extends previous findings of structural differences in the hippocampus of taxi drivers.

• The hippocampus adapts structurally to accommodate spatial representation.

• Experts' brains may have a cost, reflected in a compromised ability to acquire/retrieve new visuo-spatial information.