x-ray radiation passed thru object and onto a photographic plate
TRANSCRIPT
x-ray radiation passed thru object and onto a photographic plate
structural vs. functional
brain imaging techniques
CTMRI
PETfMRI
CT scan• x-ray & sensor• low resolution
computerized axial tomography
CT scan
reveals tumor or vascular damage
MRIhigh resolution, noisy, NO metal!
magnetic resonance imaging
structural imaging comparison
• radiation risk• low resolution
• no metal, noisy, claustrophobic• high resolution
CT SCAN MRI
PET scanpositron emission tomography
• low resolution (both temporal & spatial)
• radioactive sugar is injected
• expensive due to cyclotron
PET scanpositron emission tomography
fMRI scan
• higher spatial resolution than PET (poor temporal resolution)
• 3-D images possible
• hemoglobin (blood protein that binds oxygen) changes its magnetic field response
functional imaging comparison
• radiation risk• low resolution• cost
• no metal, noisy, claustrophobic• low res but higher than PET
PET SCAN fMRI
psychophysiological techniques(surface recordings)
“psychophysiology”
vs“physiological psychology”
EEG
psychophysiological
techniques
EOG
EMG
“electrophysiology”
= electro-myograph
= electro-oculograph
= electro-encephalograph
EEGelectroencephalography
• poor spatial resolution but excellent temporal resolution (activation)
• record of electrical activity below each electrode
EEG brainwaves characterize mental states
ERPevent related potentials:
• derived from EEG
• waves produced in response to some event are averaged together
• an ERP signal emerges as random “noise” cancels out
startle response & P300
EMGelectromyograph
MEGmagnetoencephalography
• like EEG but magnetic fields
• good spatial and excellent temporal res
SCRskin conductance/resistance
index of physiological arousal
TMStranscranial magnetic stimulation
• new, poorly understood
• produces a temporary “lesion”
• inactivates a brain area
heart rate
psychophysiological techniques
blood pressure
skin response
“polygraph”
pupil dilationsympathetic
nervoussystem
Minor incidents everyone is guilty of:
control question test
• Have you ever hurt someone else’s feelings?
• Have you ever lied to a friend?
• Do you ever exceed the speed limit?
CONTROL QUESTIONS
About the crime being investigated:
control question test
• Were you at the 1st National Bank on Jan 1?
• Did you drive a Ford sedan at the Metro
Plaza?
• Did you steal $200,000 from the bank?
RELEVANT QUESTIONS
lie detection
INNOCENT
CONTROL QCRIME RELEVANT Q
GUILTY
CONTROL QCRIME RELEVANT Q
psychophysiological techniques
“false positives”
vs
“false negatives”
Why should you care about “lie detectors”?
discussion
court
employee screeninggovernment jobslaw enforcementarmored security
psychophysiological techniques
“psychopathy”
vs
“psychopathology”