History 08/17/23 Flashcards
Polygraph
Originated from the Greek word poly meaning “many” and graphos meaning “writings”.
Instrument is not a “lie detector”, a “box” or a “machine”
Instrument measures physiological changes
Examinee does not “beat” the polygraph, he or she “defeats” the examiner
1895- Angelo Mosso
Physiologist who was interested in the vascular system and the method of blood flow through the body.
Developed a scientific “cradle” that was balanced on a fulcrum.
The non aroused subject was placed in the cradle and the cradle remained balanced
When the subject was excited the “cradle” moved in the direction of the subjects head.
Mosso theorized that the use of the “cradle” demonstrated blood flowing to the head when a person is emotional (blushing).
Made the first reported accurate studies of fear and its influence on heart activities and respiration.
Ceasare Lombroso
Physiologist and criminologist
Developed a method to detect criminals before a crime was committed utilizing body measurements.
Author of “The Criminal Mind”
Tested thirty people and claimed to have 100% accuracy.
Known as the Father of Criminology
Developed the hydrosphygmomanometer
hydro water
sphygmo blood
mano hand
meter Measure
Hydrosphygmomanometer
The “arm cuff” for blood pressure measurements.
1895 1st scientific studies reported changes in blood volume and pulse rate using the forerunner to the plethysmograph with a specialized glove. Measure of blood in the hand which is placed in a container of water.
The hand is placed in a five gallon beaker of water. Emotions cause rise in blood pressure which caused the hand to swell and the water to rise in level within the beaker.
Stylus and smoked drum used to record results
Reaction occurs in that part of the body most threatened.
Plethysmic reaction
decrease of volume in blood in hand.
Giovanni Galvanni
1897- Physiologist studying the body’s internal electrical system and its effects
Was the first individual to conduct research pertaining to electrical resistance and the secretion of sweat
Galvanometer- instrument created to measure resistance of electricity in the body or electricity introduced into the body.
John Wheatstone
Refined the galvanometer:
Electricity is introduced into the body through the hand.
Wheatstone bridge- measures the point at which the body’s electricity and induced electricity are equalized.
Increased emotion results in less body electrical resistance.Galvanic skin response (GSR)-Result of mind excitations or impressions which causes the above.
1907- Veriguth
Coined the phrase “psychogalvanic skin reflex”
GSR due to reflex of skin conductance.
There is a decrease in body electricity with increased sweat which creates better conductance of the electricity.
Sticker
Sticker- 1st to make suggestion that psychogalvanic reaction should be used for detecting deception.
Sticker stated “the galvanic skin phenomenon is under the influence of exciting mental impressions and the will has no effect on it”.
Electrodermal Response
A measure of physiologic arousal determined by the skin’s resistance to electricity
Electrical field knowledge
Present
Observable
Change in emotions produces change in GSR
At death no GSR exists, weight of body is actually reduced by several grams.
Dr. William Marston
1915- Commissioned by the US Government to study the ability of lie detection to be used as a countermeasure for espionage in World War I.
Marston was a physiologist studying responses in the cardio-vascular system who had a particular interest in systolic contraction.
Systolic Stroke
aka Anacrotic limb
Systolic beat- apex of contraction
Diastolic Stroke
aka Catacrotic limb
Semi-lunar valves slam shut in diastolic stroke to create notch.
Marston
Made measurements with a sphygnomamonometer which was a discontinuous systolic blood pressure test.
This technique used a standard blood pressure cuff and stethoscope to take intermittent systolic blood pressure readings.
Found this method to be 97 % reliable.