Sensing Techniques-Cat Scans by wpr1947

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									Sensing Techniques-Cat Scans

• Cat Scans use x-rays to show
  structures
• Really precise maps
• Hard to determine functions
Sensing Techniques-Cat Scans
Sensing Techniques-Cat Scans
Sensing Techniques-ERP Technique
    Sensing Techniques-PET
Radioactive element decays, gives off positron
Positron moves a short distance and gives off
 two gamma rays in opposite directions
Sensing Techniques-PET
              PET Scans




Eyes Closed    White Light   Complex Scene
           PET Scans



Episodic               Semantic
Task                   Task




                       Difference
PET Scans
    Sensing Techniques-fMRI

• Functional Magnetic Nuclear
  Resonance Imaging
• Similar to Pet, uses radio frequency
  information given off by water
• Gives better time (6 seconds) and
  spatial (2 mm) resolution than Pet or
  Cat scans
• Technology still under revision
• Slight danger to subjects
• Expensive ($300 an hour)
fMRI Method
MRI Scans
MRI Scans
fMRI Method
 fMRI Comparisons
   Mechanism Isolation:
Memory for Letter Identity:
   Respond Identity 3000 ms minus
   Respond Identity 1500 ms

Memory for Letter Location:
   Respond Location 3000 ms minus
   Respond Location 1500 ms

Letter Processing (Non-Automatic):
    Respond Identity minus
     Passive View Letters

Letter Processing (Automatic):
    Passive View Letters minus
     Passive View Non-Letters

Location Processing:
   Respond Location minus
    Passive View Letters
              Question

• At what level should we study the
  brain?
• Depends on the research question
• Information should be combined at all
  levels
             Summary

• Appropriate technology depends on
  question
• ERP has good temporal resolution
• CAT, Pet, MRI have good spatial
  resolution
• fMRI has both, but is expensive

								
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