Brain Scanning Techniques

• External recordings: EEG

  • Electroencephalography (EEG)
  • detects electrical activity in brain using small flat metal disks atached to your scalp
  • brain cells communicate via electrical impulses and are active all the time
  • cannot pinpoint exact location, only shows changes in brain activity
• what can elecroencephalography (EEG) pick up:

  • epilepsy
  • sleep disorders
  • head injuries
  • stroke
• still images: CAT scan

  • computed axial tomography (CAT) scan
  • produces multiple cross sectional images of inside of body like an x-ray
  • can be compared to loaf of bread
  • x-ray beans rotate around body measure readiation being absorbed throughout your body
• objective measure:

  • measured consistantly, result will not change, not subject to opinion
• limitations of computed axial tomography (CAT) scan

  • expensive
  • can expose patients to high does of radiation
  • cannot be used if patients have metal inplants
• Still images: MRI scan

  • Magnetic Resonance Imagery (MRI)
  • Lie under powerful magnets, protons in body line up
  • protons then hit with radio waves, causes them to send different waves back
  • help distinguish between variouse types of tissues (different protons realign at different speeds, produce specific signals)
  • example: same way computor has millions of pixels, signals from millions of protons are combined to create defined image of body
• Limitations of Magnetic Resonant Imagery (MRI)

  • expensive
  • time consuming
  • claustraphobic

  Pluses: no radiation used
• Scanning:

  • the act or proccess of using imageing technology to examine and study something,such as the brain
• Temporal:

  • relating to time of the sequence of events
  • example: the temporal resolution of the imaging tequnight determines how accuratly it can captute changed in brain activity over time.
• Spatial:

  • relating to space or the physical dimentins of an object or area
• Still Pictures:

  • single static images that are two-dimentional
• Dynamic pictures:

  • 3-dimentional images that change in real time
  • example: functional resonance imaging (fMRI)
• Structural imaging:

  • neuroimaging techniques that produce scans showing brain structure.
  • Example: CT and MRI scanning techniques
• Functional imaging:

  • neuroimaging techniques that produce scans showing brain functions in real time
  • example: fMRI scanning