Term 2 rev

• MRI (Magnetic Resonance Imaging)


  Based on strong magnetic fields and radio waves (detailed images of brain structures

  Alignment of atoms in water molecules
• fMRI (Functional Magnetic Resonance Imaging)


  Non-invasive brain imaging technology

  Detects brain activity by measuring changes (oxygen levels) in blood -- BOLD (Blood Oxygen Levels Detected)

  Increased oxygen levels --> increased blood flow --> greatest activity in that region
• MRI STRENGTHS


  Gives clear, detailed images of soft tissue

  Multiple images from different angles

  Painless

  No x-ray radiation

  Shows changes over time -- provides evidence of neuroplasticity
• MRI LIMITATIONS

  Time consuming and expensive

  Loud

  Can be problematic with some metal plates near organs + pace makers

  Sedation is needed for people who may not be able to stay still
• fMRI STRENGTHS

  Non-invasive and safe for the participant

  Good temporal resolution

  Neural limitations - can't directly observe individual nerve cells

  Interpretation challenges - Brain areas that "Light up" may represent multiple functions, making it hard to discern precise brain activity

  Can be used in experiments
• fMRI LIMITATIONS

  Expensive

  Can only capture clear image if the participant stays still

  Researchers currently do not fully understand how the technology works

  Results of an fMRI could be difficult to interpret
• PET study

  Chugani (1999)
• MRI study

  Maguire et al. (2000)
• fMRI studies

  Antonova et al. (2008)

  Sharot et al. (2007)
• Milner (1966) evaluation

  + High ecological validity (no variables manipulated)

  + Longitudinal (over 50 years), change could be observed over time

  -- Cannot be easily replicated

  -- Retrospective (Not much data on HM's actual cognitive abilities before the accident)
• Newcomer et al. (1999) evaluation

  + Cause & Effect established

  + Establishing baseline helped control cofounding variables

  -- no full control over extraneous variables (e.g. individual stressors)

  -- not very generalisable, memorising prose is not very authentic
• Chugani (1999) evaluation

  + correlational- determines relationship

  + unique opportunity to see the structure/function of the brain

  -- No cause/effect established

  -- Low ecological validity