History of Lie Detection 
The start of lie detection in America's legal system
The 1920’s involved an increase in academic criminology
Lying and the brain
fMRI are used to look at brain activity
Cognitive processes in person's head could be linked to the arousal of lying
John Larson and Leonarde Keeler both promoted the polygraph
There have been at least three attempts to have fMRI for lie detection in courts since 2010
Ancient Methods of Lie Detection
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In China, during 1000 BC, the rice test was commonly used
Based off the principle that fear and anxiety reduce saliva production
"Trial by Ordeal" methods based off of religion opposed to physiological factors
Based off the idea that God would not let an innocent person suffer
Hot water test
Cold water test used to test supposed witches
Not approved yet
There are new inventions for lie detection always being made and improvements with the fMRI
fMRIs show neural activity
Images show the flow of blood and what parts are receiving oxygenated blood in the brain
African medicine men believed they could smell out a liar
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In North Bengal, the Red Hot Iron Ordeal was commonly used
Larson reported his studies and ideas in journals
Keeler promoted his work to the military and intelligence agencies during WW2 and the Cold War
Cold War Era filled with suspicion among Americans
Government used lie detection to combat communism
Government also used lie detection to combat homosexuality
Investigative Units were set up to deal with moral deviations within state departments
These investigations mostly dealt with suspected homosexuals
Led to many forced resignations
Lie detection became a form of intimidation
Many people contributed to the idea of a polygraph
Body Movements and Facial Expressions
Your body does not know how to lie
Sweating
Body language experts study peoples body language when being questioned
Body involuntary starts to sweat
Eye movement
Looking away or staring
Moving around
Nervously moving around or shaking
Used in criminal cases to interview suspects, witnesses, and victims
Body language theorist think there is a reason for the way you walk, sit, shake hands, really any movement that you do
Speech
Stuttering words when you are trying to talk
Changing you story
Getting angry and defensive
Emotions play a role as well. Anxiety, guilt, and fear
Polygraphs form charts based off physiological changes in respiration, blood pressure, heart rate, and electrodermal responses
Polygraphs used for screening clearances and investigations
Sympathetic Nervous system releases adrenaline after an individual tells a lie,which can stimulate some of these physiological changes
Franz Gall suggested using Phrenology to detect if a lie is being told
He believed certain areas of the brain represented an individuals tendency to lie
Often involved fire, water or poison
Person would lick a hot iron to see if bruising occurred
Involved stick hand in boiling pot of water to see if blistering occurred
Poison was commonly used in India and Africa
Some think that people waiting on death row should be able to have an fMRI scan as evidence
Some scientist say the fMRIs should only be used when the stakes are not high
Paul Ekman has taught himself and others how to know when someone is lying
He looks at micro expressions that occur in 1/25 of a second
Highest form of technology, and most accurate for catching people in a lie.
fMRIs are not bias and show real results