Lecture 9 Flashcards
What is our lie detection hit rate? chance rate?
hit 54%
chance 50%
What did Paul Ekman do in his studies? what were the results?
He made vignettes and showed them to psychiatrists, judges, police, FBI, CIA and Secret Service and tested their ability to detect lying.
The only group who did were Secret Service because they are trained to detect small physical changes/facial expressions
What does Paul Ekman study?
Facial Expressions
What three groups of people are best at detecting lying? Why?
Secret Service
Abused Children
Someone who has had a left hemisphere stroke
They all pay extra attention to body language and facial expressions
What is the problem with detecting lies with imaging?
the areas that light up during lying also light up during decision making
What part of the brain lights up when lying?
anterior cingulate cortex
What is a Steady State test?
It is a type of Biological examination.
You take a sample of individuals that fit a category: Clinical vs Control group
Take some kind of Biological Measure: urine, hair, cerebrospinal fluid etc..
What part of the face is more active when lying?
The eyes
What is the main issue with Steady State tests? give an example
The further away from the brain the more variability.
Ex: Learning disabled kids found to have increased levels of Cadmium and Lead in their hair compared to control BUT it’s not specific increased Cadmium and Lead also found in murderers
What is the average rate of false positives for Drug Screening?
25%
Why might an employer want to screen for drug users?
more likely to have increased absenteeism, accidents, health claims
What is Brain Electrophysiology?
It’s a measure of electrical activity in brain
What is the P300 response
using EEG to look at how you respond to a specific stimulus
look for abnormalities in response
What do you call measuring brain waves?
Electro-enceph-algorams (EEG) note: no hyphens
What is Neurometrics?
take EEG recordings from all over the brain and put together a profile
What is a CAT scan?
Computerized Axial Tomography
2D X ray pictures of multiple slices that are computer analyzed
Camera that circles around the head
What is an MRI? What is involved?
Magnetic Resonance Imaging
- Produce a magnetic field around the head
- Causes Hydrogen Atoms to align their electrons with magnetic field
- when magnetic field is Stopped atoms are measured as they return to their original axis
- Picture are taken of this
What is an issue with the CAT scan?
Poor Resolution
What are the structural abnormalities discovered through MRI in OCD? Schizophrenia?
OCD: larger caudate nucleus
Schizophrenia: Smaller thalamus, smaller frontal cortex, larger ventricles
People high in extroversion have differential functioning in which area of the brain? what is a function of this area?
MOFC
Medial Orbital Frontal Cortex: involved in processing reward information
What is an fMRI
Functional Magnetic Resonance Imaging
Measures blood oxygenation
What is a PET scan?
Positron Emission Tomography
injection of radioactive substance that binds to neurotransmitters to trace them. Take pictures.
What are some disadvantages of Brain Imaging?
- Assumptions: when we’re looking at neural activation, we’re not really measuring neural activation. we’re measuring blood oxygenation or blood flow and ASSUMING
- Generalizing from groups to individuals
- What your measuring isn’t always clear: ex: lying and decision making activate the same parts of the brain
What are some other Cautions professor Pihl gives about Brain Imaging?
- Neural Abnormalities can be present without being involved in the disorder’s development or expression
- Neural Activation of an area can represent a general response associated with a broad range of behaviors
- fMRI measures blood flow change not neuronal activity (Assumption)
- Not a steady state: ex psychotherapy can change whats happening in the brain so maybe it’s not as much of a brain disease as we think
