Recalling Routes around London: Activation of the Right Hippocampus in Taxi Drivers - Maguire, E.A., Frackowiak, R.S.J. and Frith, C.D. (1997)

Aims

  • To examine semantic topographical memory retrieval and to determine if recall of well established spatial layouts activates similar brain regions as noted in other studies.
  • Examine topographical (landmarks, spatial layouts) semantic memory versus non-topographical semantic memory versus non-topographical semantic memory and see if common brain regions were activated.
  • Participants

  • Licensed London taxi drivers
  • Must have 3 years of training and tests of spatial knowledge
  • 11 males participants
  • Ages 38-52
  • Research Method

    The research method used in this study was a Lab experiment.


    Procedure


  • Questionnaire (Areas of London which they were most familiar with, Movies that were common among all, Landmarks they had visited in person and could envision in their head)
  • Arrived for scans, participants were blindfolded and speech was recorded visually
  • Each task, one stimulus at a time
  • PET scans
  • Findings


  • All spoke about same amount of time
  • High accuracy on all tasks
  • Navigation task, routes chosen were similar
  • During tasks, subjects stated they visually noted the paths, landmarks, and movies


  • Strengths


  • Real world routes and landmarks
  • All overly qualified (3 years training min.)
  • All from same area (familiar with routes)
  • Questionnaire

  • Ecological Validity


    High ecological validity
  • No deception
  • No incentive to lie (no reward)
  • All asked same routes, landmarks, movies
  • Explanations


  • Routes: Activation of the hippocampus in topographic memory retrieval. Specifically the right hippocampus. Since real world environments were used, the study suggests that this may reflect the role of the hippocampus in high level spatial manipulation and decision making.
  • Landmarks: The main difference between activation patterns for routes and landmarks was that the right hippocampus was activated only in the routes task but not during recall of landmarks. The landmarks lacked a location within a large-scale spatial framework and thoughts of navigation between them were not possible, again suggesting a role for the right hippocampus in the crucial complex stage of facilitating navigation in large-scale space.
  • Semantic memory: Except for cerebral activity, the brain regions activated during recall of movie plots was different from routes tasks. Most brain activity was on the left side of the brain.


  • Weaknesses


  • Only male subjects
  • Only 11 subjects (more would have made it more accurate)
  • Conducted in a lab

  • Ethics


    Nothing ethically wrong with it (no harm/damage)

    Maguire, E.A., Frackowiak, R.S.J. and Frith, C.D. (1997)


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