Applied Psychophysiology Flashcards
Human as lie detector (2)
54% accuracy
Detecting facial expressions
Deception detection
Application
Mostly used by government agencies
Brain Fingerprinting
Guilty Knowledge Test (GKT)
A P300-MERMER (P300 + LNP)
Three types of stimuli are used:
Targets (known to everyone)
Irrelevant (immaterial information)
Probes (known only to perpetuator)
Targets (known to everyone)
Red: information that the suspect knows, whether or not he committed the crime crime
Irrelevant (immaterial information)
Green: information not known to the subject
Probes (known only to perpetrator)
Blue: crime-relevant information only the perpetrator would know
“Information absent”
Brainwave response of an innocent suspect to stimuli relevant to a murder
“Information Present”
Brainwave response of a serial killer to stimuli relevant to a murder
Detection Deception
Event related brain potentials
Advantages (2)
NOT dependent on ANS
Less vulnerable to countermeasures
P3 and countermeasures
Wiggling toes and imagining being slapped wiped out the P3 in one study
Vigilance
Detection of random, infrequent signals over time
Terms related to vigilance (4)
Boredom/monotony, vigilance, workload
P300
Good indicator of workload
Vigilance diagram
P300 elicited by infrequent counted tones when presented (3)
Concurrently with 8 display elements
Concurrently with 4 display elements
Count only tones (highest)
Vigilance meaning (what I wrote)
How quickly you respond to targets vs. nontargets
(Alertness)
Example of vigilance:
Air traffic controllers
P300 good indicator of workload meaning
Response to infrequent tones (positive or negative)
What does P300 mean?
3rd wave (P3)
300 ms of ERP (event)
P300 components (2)
Amplitude (either positive or negative)
Latency (time)
Scalp distribution
N2-P3 complex
Earlier potential:
Exogenous (related to environmental stimuli)
Later potential:
Endogenous (related to cognitive processing)
Increase workload
P3 in P300 decreases
Clinical applications
Auditory and Visual evoked potentials
Detects hearing loss in newborns
Useful for detecting hemianopia (if there’s a blind field- blindness over half the field of vision)
Clinical applications
Clinical populations
Down’s syndrome- Lack of ERP habituation
HIV- Smaller Auditory P300 amplitude
Clinical applications meaning (what I wrote)
Potential to open up ideas to what this means, what part of brain, what’s going on early on
Clinical applications
EEG abnormalities detected in (4)
Tumors, encephalitis, epilepsy, meningitis
In the waking adult (3)
Delta (associated with hemorrhage, tumor)
Spike activity (epilepsy)
Note: abnormal EEG in ~20% of healthy subjects
Epilepsy (what I wrote)
NEED EEG (diagnosed based on individual’s brain capacity)
In the waking adult (what I wrote)
Ex: no delta during the day
Specific pattern expect to see when asleep, specific characteristics when awake
Clinical Applications
Diagnosing Multiple Sclerosis
Event Relation Potentials (ERP) complements MRI
Diagnosing Multiple Sclerosis
Event Relation Potentials (ERP) complements MRI (2)
Small lesions not visible in MRI are captured by ERP
But ERPs don’t always reveal lesions well defined by MRI
Clinical applications
In brain death
EEG & ERP
In brain death
EEG & ERP
Auditory ERP (3)
Waves I-II: 8th cranial nerve
Waves III-IV: Medulla and pons
Waves V: Midbrain (colliculi)
Waves I and II result from…
While later waves
Wave V
The eighth nerve
Reflect postsynaptic activity in major brainstem auditory centers.
The component most analyzed in clinical applications, originates from the inferior colliculus
Clinical applications
In schizophrenia (2)
Higher voltage beta activity (24-33 Hz) compared to controls & diminished alpha
Electrodermal activity (EDA) generally higher in chronic schizophrenics (hyper arousal)
Hyper arousal (what I wrote)
Association cortex
Clinical applications
In Attention Deficit Hyperactivity Disorder (ADHD) (3)
EEG suggest cortical hypo arousal
Low frequencies (theta & alpha) are HIGH
Beta LOW
Theta/beta ratios
Clinical applications
Predicting degenerative disorders (3)
Alzheimer’s, Substance abuse, Depression
Predicting degenerative disorders
Alzheimer’s (2)
P300 amplitude in 1st degree relatives of Alzheimer’s patients
In Alzheimer’s patients, auditory P3 is reduced and scalp topography changed (larger in frontal sites when typically P300 is larger in posterior)
Predicting degenerative disorders
Substance abuse (2)
P300 amplitude LOWER in sons of alcoholic fathers
Another study, poor control of EDR in response to predictable loud noise (most likely due to poor inhibitory control)
Predicting degenerative disorders
In depression
Left frontal hypoactivation: More alpha activity in the left frontal lobe (less beta) than in the right frontal lobe
