lecture 4

  1. who discovered that nervous activity has electrical basis and what year
  2. neurons electrical activity is recroded called ______
    action potentials
  3. what is the purpose of electro enectroencephalogram
    show electrical activity caused by nerve cells firing. they recorded brain waves which reflect speed of firing in different states of mind
  4. how are electroencapholgram used
    • electrode attached to skull
    • electrode connected to magnets which connected to pens
    • record electrical activity in brain
  5. what are imaging mathods that are structural^diagnostic
    • X-rays
    • CT scans
  6. how is computeruzed tomography (ct scan) used
    • xray beams passed through brain at different angles
    • it is good at identifying structures
  7. how is positron emission tomography used (PET)
    • radioactive molecules injected into bloodstream or inhaled and detected by PET cameras
    • show areas of high and low blood flow in brain
    • high levels indicate high level of cognitive processing
  8. explain scan subtraction method
    • determine average neural response to cognitive task
    • scan person at rest and then scan person doing cognitive task. take neutral and cognitive signal.
  9. what is magnetic resonance imaging (MRI)-functional MRI
    • use large magnet and radio frequency pulse to generate brain signal that produces image
    • different curves for protons in oxygenated and unoxygenated blood provides functional image
    • neurons more actve=more oxygen used
    • FMRI patient scanned while performing cognitive task
  10. who determined speed of electrical conduction and what date?
  11. who invented the first EEG (electroencephalogram)?
    what does it do?
    • Berger-1924
    • patern of electrical activity in brain
  12. when was PET and MRI/fMRI method of imaging discovered?
  13. what does PET measure?
    glucose absorption caused by increase in mental activity
  14. what does MRI/fMRI and MEG measure?
    heightened blood flow/ oxygen using re alignment of magnetic fields
  15. frontal polar cortex
    forward planning and control other brain regions
  16. what are color codes of cerebrum, cortex, cerebellum and brainstem?
    • cerebrum-red
    • cortex-yellow
    • cerebellum- blue
    • brainstem- green
  17. what is function of amgydala?
    control of emotion
  18. what is the function of hippocampus?
    memory formation; spatial navigation
  19. cerebellum
    • fine motor control and timing of movements
    • balance and stability
  20. primary visual cortex
    signal arrives from eyes via thalamus
  21. what is diffusion tension imaging?
    • type of MRI that measure water flow among neurons
    • identify neural network of brain
  22. what is magnetocephalography (MEG)?
    • superconducting coils detect brains magentic field
    • acurately pin points sources in primary auditory; somatosensory and motor areas
    • asist in clarification of functional organization of primary somatosensory cortex
  23. what is trancranial magnetic stimulation (TMS)?
    • coil is activated over cortical area of brain and disturbs normal electrical acivity
    • used to identify areas of brain used to produce movement and motor learning studies
    • pertubation of motor area prevent learning of certain types of motor skills
  24. what are advantages of imaging methods?
    • display changes in neural activity throughout brain
    • high spatial resolution (2-4mm)
  25. what are disadvantages of imaging methods?
    • restricted movements
    • poor temporal resolution (3-4 sec to get image)
    • difficult to endure- noisy- closterphobic
    • expensive
    • difficult to analyze data
Card Set
lecture 4
methods of imaging the brain