Brain scans

• Structural imaging -

  static image of the brain

  Localisation of different brain

  CT
• functional imaging -

  Image of what the brain is doing

  Brain areas active

  FMRI, PET
• Alzheimer’s disease

  Smaller brain = less brain tissue

  Larger gaps between hemispheres

  More damage to left side of brain - controls cognition
• CAT

  x-rays past through the brain in multiple angles

  Creates an image of the brain

  Measures - areas of the brain which are damaged, positions of tumours

  Doesn’t show parts of brain which are active
• PET

  Injected with radioactive tracer - absorbed into bloodstream and binds to glucose molecules more glucose = more active
• risks, usefulness and limitations of CAT scan

  • x-ray radiation can damage unborn babies
  • quick to conduct showing accurate details of brain structure
  • only tells you structural info not functional so limited use in researchers
• • risks, usefulness and limitations of PET
  • low risks but unclear about long term effects
  • indicates specific areas of brain involved in an experience- localisation of function in the brain
  • FDG is radioactive so can damager cells and tissues in the body - scan can only be done once every 6 moths
• FMRI

  Electromagnetic hydrogen in water molecules in brain align with magnet

  Blood cells with oxygen will repel magnetic field

  Changes measured by computer

  Areas of brain that have more oxygen are more active
• risks, usefulness and limitations

  • low risk but people with surgical implants, pacemakers cannot use it
  • indicate specific areas of the brain being involved in an experience (used to observe increase O2 usage in amygdala when participants are aggressive
  • only effective when person investigated is still so problematic for young children/motor disabilities
• Overall strengths - reliable, compared to establish connections between brain areas and behaviour
• Overall weakness - task are low mundane realism, may not trigger or activate brain in the same way