Maguire (2000)

Neuroplasticity

• The brains ability to reorganise itself by forming new neural connections throughout life, often in response to learning or environmental demands

  Localisation of function

• The concept that specific areas of the brain are responsible for specific functions

  Hippocampus

• A region of the brain associated with memory and spatial navigation

  MRI (magnetic resonance imaging)

• A technique used to create detailed images of the brains structure, measuring grey matter density and brain volume

  CONTEXT

• The study investigates neuroplasticity by hypothesising that the brains of London taxi drivers would adapt structurally to the demands of learning and recalling complex spatial information

  AIM

• To determine if extensive spatial navigation experience alters the structure of the hippocampus

  METHOD

• Experimental group, 16 right handed male London taxi drivers who passed the “Knowledge” test and held a taxi licence for at least 1.5 years

• Control group, 50 right handed males who did not drive taxis, selected from MRI database

  DESIGN

• Quansi-experiment, IV (taxi driver experience) was naturally occurring

• Single blind , the researcher analysing the MRI scans did not know whether scan belonged to a taxi driver or a control participant

  PROCEDURE

• Participants went through MRI scans, analysed using 2 methods;

• Voxel based morphometry, measured gray matter density

• Pixel counting, measured hippocampal volume

  FINDINGS

• Posterior hippocampi, significantly larger in taxi drivers compared to compared to controls

• Anterior hippocampi, significantly larger in taxi drivers compared to controls

• Correlations, the volume of the right posterior hippocampus increased with years of taxi drivers

  No differences were found in the other brain regions

  This suggests that the posterior hippocampus is involved in recalling previously learned spatial information while the anterior hippocampus is associated with encoding new layouts

  EVALUATION

  Strengths

• Controlled design, single blind study reduced researcher bias

• Control of confounding variables, such as age and handedess, strengthened internal validity

• Correlational analysis, the relationship between the years of taxi driving and hippocampal volume supports the role of experience in brain structure changes

• Use of mri, provides precise measurements of brain regions, enhancing reliability

• Ecological validity, focused on real life behaviour rather an artificial tasks, making findings applicable to everyday experiences

  Limitations

• Quasi-experiment, no cause effect relationship can be established since IV was not manipulated

• Sampling bias, all participants were male and right handed, limiting generalisability reflecting demographic of London taxi drivers but not otherrs

  ALTERNATIVE EXPLANATION

• individuals with larger posterior hippocampi are predisposed to become successful taxi drivers

  ETHICAL CONSIDERATIONS

• Informed consent

• No harm, mri is non invasive and no health risks

• Confidentiality, participant data was anonymised to protect privacy

• Debriefing, informed about studies aim and findings

  UNANSWERED QUESTIONS

• Would training in other areas , such as music or sports lead to similar structural brain changes ?

  PRACTICAL USES

• Insights into neuroplasticity could inform therapies for brain injury or degenerative condition

  CONCLUSION

• this study highlights the role of the hippocampus in spatial memory and demonstrates the brains ability to adapt to environmental demands proving strong evidence for neuroplasticity and localisation of function