POLYGRAPHY

Polygraphy – is scientific methods of detecting deception done with the aid of a polygraph instrument.

Polygraph = (derived from the Greek words Poly) = many or several and Graph =  (writing chart) is a scientific instrument capable of recording simultaneously changes in blood pressure, pulse rate, respiration and skin resistance as indicative of emotional disturbance especially of a lying subject when being questioned.

Thomas Jefferson = firs person known who used the term Polygraph to described one of his inventions

Definition of terms

1.    Admission = is a statement of facts, partial acknowledgement of guilt and usually given with some justification or exemplification in admitting.

2.    Confession = direct acknowledgement of guilt or a statement of guilt.

3.    Deception = is the act of deceiving or misleading usually accompanied by lying.

4.    Diastolic blood pressure = refers to the downward blood pressure representing the low pressure to the closing of the valves and heart relaxed.

5.    Dicrotic notch = refers to the short horizontal notch in a cardio-tracing located at the middle of the diastolic stem.

6.    Electrodermal response = it refers to human body phenomenon in which the skin changes resistance electrically upon the application of certain external stimuli. Also referred to a Psycho galvanic skin reflex or galvanic skin response.

7.    Emotion = it refers to an emotional response to specific danger that appears to be beyond a persons defensive power.

8.    Environment = is the sum total of the dissimulation that a person acquired from the time he was conceived and his exposure to his surroundings.

9.    Heredity = is the transmission of physical and mental traits of the parents to their offspring through the genes.

10. Interview = simple questioning of one who is willing and cooperative.

11. Interrogation = forceful questioning of a person who is reluctant to divulge information.

12. Lying = is the act of uttering or conveying falsehood or creating a false or misleading impression with the intention of affecting wrongfully.

13. Normal response = refers to any activity or inhibition of a previous activity of an organism or part of the organism resulting from stimulation.

14. Ordeal = refers to the oldest form of crime detection done by subjecting a subject to an obstacle or trial and sometimes even involving third degree.

15. Specific response = refers to the response given by the subject which considered a deviation from the normal tracing or norms of the subject.

16. Stimulus = refers to any force or motion coming from the environment and which reach an organism has the tendency to arouse.

17. Systolic Blood pressure = the upward blood pressure as the apex of the curve caused by the contraction of the heart, valves are open and blood is rushing into the arteries.

Ayur Vida = a hindu book of science and health around 500B.C. Considered as an earliest known reference to a method of detecting deception.

EARLY METHODS OF DETECTING DECEPTION

1. Trial by Combat = a method to settle accusations in the absence of witnesses or a confession, in which two parties in dispute fought in single combat.

2. Trial by Ordeal = a judicial practiced by which the guilt or innocence of the accused is determined by subjecting them to an unpleasant, usually dangerous experience or in the present term would mean an employment of “3^rd degree”. The word “ordeal” was derived from the Medieval Latin word “Dei Indicum” which means “a miraculous decision”.

TYPES OF ORDEAL

1. Ordeal of Heat and Fire = in this test the suspect walked a certain distance, usually nine feet, over red-hot plowshares or holding a red-hot iron.

2. Ordeal of Hot Water = this test requires that the water had to be boiled, and the depth from which the stone had to be retrieved was up to the wrist for one accusation, and up to the elbow for three or more accusations.

3. Ordeal of Boiling Oil = this ordeal was practiced in villages of India and certain parts of West Africa.

4. Red Hot Iron Ordeal = the accused will be required to touch his tongue to an extremely hot metal nine (9) times (unless burned sooner), Once his tongue is burned, he will be adjudged guilty. In some country instead of hot iron, they used a hot needle to tease the lips and once the lips bleed it is an indication of guilt.

5. Ordeal of Cold Water = this ordeal has a precedent in the Code of Ur-Nammu and the Code of Hammurabi under which a man accused of sorcery was to be submerged in a stream and acquitted if he survived.

            = in 16th and 17th centuries, ordeal by water was associated with the witch-hunts. Floating is an indication of witchcraft.

6. Ordeal of Rice Chewing = a method of detecting deception whereby an accused will be required to take rice (to clergy bread or cheese).If the accused failed to swallow even a single grain of concentrated rice he/she will be adjudged guilty.

7. Ordeal of Red Water  (Food and Drink Ordeal) = in this method the accused will be required to run fast for twelve (12 hours), take a cap of rice and drink a dark colored water (as much as one gallon).

8. Ordeal of the Cross =  the accuse and the accuser stood on either side of a cross and stretched out their hands horizontally. The one to first lower his arms lost.

9. The Test of the Axe = in Greece, a suspended axe was spine in the center of a group of suspects, when the axe stopped, whosoever was in line with the blade was supposed to be the guilty as pointed by divine providence.

10. The Test of the Candle = this ordeal was used in Burma, the accuser and accused were each given identical candles and were lighted at the same time. The candle that burns the longest determines which the truth.

11. Donkey’s tail (Ash tail) Ordeal  = a method of ordeal where all accused persons will be instructed to select a cage with a donkey, using a donkey’s tail they will strike the donkey and whichever cries first will be adjudged guilty.

12. The “Hereditary Sieve” = Dr. Hans Gross mentioned this Ordeal in his famous book on Criminal Investigation in which beans were thrown into a sieve as the name of each suspect was called. The deception criteria were described as follows--- “If the bean jumps out of the sieve, the owner of the name pronounced is innocent, if the bean remains in the sieve, the person named is the thief.

IMPORTANT PERSONS IN THE DEVELOPMENT OF POLYGRAPH

Daniel Defoe = wrote an essay entitled, “An Effectual Scheme for the Preventing of Street Robberies and Suppressing all other Disorders of the Night”

Angelo Mosso = In 1878, science came to the aid of the truth seeker through the research of an Italian psychologist Angelo Mosso. He made used of an instrument called plethysmograph in his research on emotion and fear and its influence on the heart and respiration. 

            = developed a scientific cradle

Cesare Lombroso = In 1895, Cesare Lombroso, an Italian Criminologist and tutor of Angelo Mosso, published the second edition of his book entitled “L’Homme Criminel” which he relates the used of hydrosphygmograph during interrogation of suspects. He  called it blood pressure pulse test.

            = he is considered as the first person to conceive the idea of lie detection and the first to apply the technique in actual criminal suspects

Francis Galton = in 1879, introduced the Word Association Test using series of irrelevant questions and relevant question separated in time.

B. Sticker = believed that the origin of the galvanic skin phenomenon was under the influence of the exciting mental impressions and that the will has no effect upon it.

            = he made the earliest application of psychogalvanometer to forensic problems.

Sir James Mackenzie = an English clinician and cardiologist, constructed the Clinical Polygraph in 1892, an instrument to be used for medical examinations with the capability to simultaneously record undulated line tracings of the vascular pulses (radial, venous and arterial), by way of a stylus onto a revolving drum of smoked paper.

In 1906, Sir James Mackenzie refined his clinical polygraph of 1892 when he devised the Clinical Ink Polygraph with the help of Lancashire watchmaker, Sebastian Shaw. This instrument used a clockwork mechanism for the paper-rolling and time-marker movements and it produced ink recordings of physiological functions that were easier to acquire and to interpret.

S. Veraguth = he is said to be the first person to use the term Psychogalvanic Reflex. Veraguth was the first scientist to use the word association test with galvanometer.

            = in 1907, he described his observation on galvanic phenomena and emotions that there was an ascending galvanometer curve during the presentation of relevant stimuli versus the rest curve on non-crucial stimuli.

Vittorio Benussi = in March 1913, he presented a paper before the second meeting of the Italian Society for Psychology in Rome where he described how he record the subject’s breathing patter using a Marey Pneumograph which he noted the changes in inspiration-expiration ratio during deception.

             = he also included recording of heart rate and blood pressure curve in detection of deception and probably the first person to record more than one physiological response.

Dr. William M. Marston = in 1915 was credited as the creator of the systolic blood-pressure test used in an attempt to detect deception during questioning, and using a standard blood pressure cuff and stethescope, requiring repeated inflation of the pressure cuff to obtain readings at intervals during examination. This was called Discontinuous Technique.

Harold Burtt = In 1918, Burtt suggested that the changes in respiration were an indication of deception.

            = He was able to determine that the changes in respiration were of less value in the detection of deception than the changes in blood pressure

John A. Larson = encouraged by August Vollmer of the Berkeley Police Department to conduct a research on deception.

            = Cardio-Pneumo Psychogram was Larson’s first instrument which was borrowed from Dr. Robert Jessel and was invented by Earl Bryant

            = in 1921, Earl Bryant made an instrument for Larson in which he used a breadboard as a base and from that it became in the industry as Breadboard Polygraph – capable of recording continually and simultaneously the respiration and cardiovascular activities.

            = today he is known as the Father of Scientific Lie Detection and at the same time the Father of Polygraph

Leonarde Keeler = in 1926, he made a modification of Larson’s instrument. He developed that metal bellows and kymograph that pulled a chart paper at a constant speed under recording pens from a roll of chart located inside the instrument.

            = in 1938, 1938, Keeler included the Psychogalvanometer (PGR), a third measuring component of his instrument which was also known as Galvanic Skin Reflex (GSR) invented by Italian Physiologist Galvani in 1791.

            = credited as the creator on Relevant-Irrelevant Technique.

            = today Keeler is known as the Father of Modern Polygraphy.

Ruckmick = in 1936, the term Psychogalvanic Reflex used by Veraguth was repudiated by Ruckmick and proposed the term Electrodermal Response.

John E. Reid = in 1950, he developed the Control Question which consist of a known lie and incorporated it into the relevant/irrelevant technique.

            = he developed a movement or activity sensor a means of recording arm and leg movements

            = Reid also developed the silent answer test and guilt-complex test to be administered to overly responsive examinee

Cleve Backster = developed the psychological set theory and the anticlimax dampening concept.

            = he also developed and introduced the Quantification System of Chart Analysis (Numerical Scoring) which permits the examiner to score the charts numerically according to standard rules.

Richard O. Arther = introduced the Arther II polygraph instrument which contains a stimulus marker capable of recording the beginning and ending of question and the moment the examinee answered.

            = credited as the creator of Stimulus Marker

            = developed an instrument with two Galvanic Skin Resistance

Computerized Polygraph Instrument = in 1992, the polygraph made its official entrance into the computer age

TRIPOD FOUNDATION OF POLYGRAPHY

1. Psychological Leg Premise = states that specific nervous system component whose stimulation can thus be diagnosed are so stimulated by the involuntary and emotional processes of the individual who is continuously attempting concealment of deception especially if that individual has something at stake and the prevailing circumstances lead him to believe that exposure to deception is quite possible although undesirable.

2. Physiological Leg Premise = that among the physiological responses that may be recorded are those that automatically occur only following the stimulation of specific nervous component system

3. Mechanical Leg Premise = polygraph is capable of making graphic record containing reliable information regarding physiological responses of the subject.

PSYCHOPHYSIOLOGY OF LYING

The Central Nervous System (CNS) = is composed of the brain and the spinal cord. All other nerve ways are within the peripheral nervous system which separates into two: The Somatic Nervous System and the Autonomic Nervous System.

1. Somatic Nervous System = is involved with voluntary comparative over skeletal muscles

2. Autonomic Nervous System = involved those involuntary physiological functions of the body and has considerable psychological impact as well.

TWO DIVISIONS OF AUTONOMIC NERVOUS SYSTEM

1. Parasympathetic Nervous System (PNS) = the house keeping or braking system. It is responsible for conserving energy and making sure necessary bodily functions. I

            = restrains sympathetic arousal and attempt to maintain homeostatic (homeostasis) normal.

2. Sympathetic Nervous System (SNS) – is our emergency, or action system.

            = a system which causes the sudden and dramatic change.

Homeostasis = is complex interactive regulatory system by which the body strives to maintain a state of internal equilibrium.

Hypothalamus = is a series of groups of nerve cells of the brain that control the entire endocrine-hormonal system.

Fight, flight, freeze = are the three stereotypic behavioral responses to threat, sometimes simply called F3. The physiological responses concomitant to these behaviors are the same, namely mobilizing bodily resources for an expenditure of energy, and narrowing attention and focus to the features of the threat.

                       

            When the sympathetic nervous system is activated, it immediately prepares the body for fight or flight by causing the adrenal glands to secret hormones known as epinephrine and norepinephrine and the blood will be distributed to those areas of the body where it is most needed to meet the emergency.

Epinephrine = is the hormonal stimulator of the sympathetic nervous system. It acts to constrict peripheral blood flow, raise blood pressure, increase cardiac activity, promote metabolic activity through the release of glucose, and inhibit digestive processes.

            = it is called Adrenaline in British

Norepinephrine = is a hormone secreted by the adrenal gland, it works alongside with epinephrine/adrenaline to give the body sudden energy in times of stress, known as the "fight or flight" response.

            =it is called Noradrenaline in British.

MAJOR COMPONENTS OF POLYGRAPH

1. Pneumograph = designed to detect and record changes in respiration of the subject which consists of the ff:

n  Rubber Convoluted Tube = about 10 inches corrugated rubber attached to the body of the subject.

n  Beaded Chain = used to lock the rubber convoluted tube.

n  Recording Pen Unit = consisting of two 5 inches recording pen

n  Centering Knob = used to center the pen

n  Sensitivity Knob = used to adjust the desired size of tracings

n  Vent = used to release excess pressure from the system

n  Pneumo Module = located inside the instrument that receives the reactions detected by the corrugated tube and moves the pen to record the reactions on the chart

2. Cardiosphygmograph = Designed to detect changes in the cardiovascular activity of the subject. It consists of:

a. Blood Pressure Cuff = attached to the upper right arm of the subject, above the brachial artery.

b. Sphygmamonometer = used to indicate the amount of air pressure inflated to the system.  Usually about 60 mm of mercury for male subject.

c. Recording Pen Unit = five (5) inches length

d. Air Pump/Pump Bulb = designed to supply air to the system

e. Cardio Module = located inside the instrument that receives the reactions detected by the cuff and moves the pen to record the reactions on the chart

f. Sensitivity Control = used to adjust the desired size of tracings

g. Centering Control = designed to center the pen on the chart

h. Vent = Used to release excess pressure from the system

Cardiosphygmograph provides a record of the following:

1. Relative Blood Volume/Pressure = is the changes in the average value of the cardio tracing (waveform) with respect to a baseline.

a. Diastolic Blood Pressure = refers to the downward blood pressure representing the low pressure to the closing of the valves and heart relaxed.

b. Systolic Blood Pressure = the upward blood pressure as the apex of the curve caused by the contraction of the heart, valves are open and blood is rushing into the arteries.

2. Pulse Amplitude = is the changes in pulse amplitude (tracing height) independent of baseline.

3. Pulse Rate = changes in heart rate or time between pulses.

4. Dicrotic Notch = changes in relative position of the dicrotic notch or pulse waveform

= short horizontal notch in a cardio-tracing located at the middle of the diastolic stem

3. Galvanograph = designed to detect changes in skin resistance of the subject. Consists of:

a. Finger Electrode Assembly consists of:

a.1. finger Electrode Plate and Retainer Bond = attached to the index  and ring finger of the subject.

a.2. Connecting Plug = attached the system to the instrument

b. Recording Pen Unit = usually 7 inches

c. Amplifier Unit = designed to support the galvanometer in converting electrical to mechanical current.

d. Sensitivity Control = used to adjust the desired size of tracings

e. Centering Control = designed to center the pen on the chart

f. GSR Module = located inside the instrument that receives the reactions detected by the finger electrodes and moves the pen to record the reactions on the chart

How does it Records?     

            Galvanic Skin Response = is the change in the body’s resistance to the passage of a minute electrical sensing current.

            The electrodes electrically connect the subject to the instrument. These provide a 5 microamp sensing current to the subject, far below the threshold of feeling.

Keymograph = serves as the paper feed mechanism of the polygraph machine

            = It is a motor that pulls or drives the cart paper under the recording pen simultaneously at the rate of five seconds per vertical chart division or twelve divisions in one minute run.

a. Chart = approximately 100 ft. rolled graph paper with approximately ¼ inch horizontal division and ½ inch vertical division equivalent to 5 seconds run

            b. Cutter Bar = used to cut the paper at the end of the test

            c. Rubber Roller = the one responsible for pulling the paper out of the machine.

            d. Pen Table = flat portion where the pen write on the chart.

e. Paper Rail Guide = serves as the security for the unnecessary movement of the chart paper or to ensure the paper’s forward movement without shaking.

f. Synchronous Motor = runs the chart paper at the uniform rate speed regardless of the voltage change.

Pen and Inking System = the one that provides for the permanent record of the test

Capillary Ink = a water based ink intended for polygraph instruments

FORMULATION OF TEST QUESTIONS

General Rules in formulating Test Questions

n  Questions must be simple and direct

n  They must not involve legal terminologies

n  They must be as simple and as short as possible

n  Answerable by Yes or No.

n  They must not be in a form of accusatorial.

n  Their meaning must be clear and they must be phrased in a language that the subject can easily understand.

n  They must never contain inference which presupposes knowledge on the part of the subject.

n  They must refer to one offense only

n  They must refer to one element of the offense.

n  They must not contain inference to ones religion, race or belief.

1. Irrelevant Question = a question that has no connection with the matter under investigation and deals with known facts that the subject cannot be denied. It is designed to be emotionally neutral to examinees and usually answerable by “yes’. Also called Neutral Question.

Characteristics of Irrelevant

1. It has no connection to the matter under investigation.

2.No threat to subject (usually).

3. Neither innocent nor guilty suspects have reason to lie.

4. Usually about the suspect’s background.

5. Generally used at the beginning of polygraph technique to establish a ‘norm’ for examinee, or throughout the examination as needed to reestablish norm pattern.

Purposes of Irrelevant Question

1. Establish the professional authority in the room that means, the examiner asks questions and the suspect answers.

2. It allows the examiner to assess the subject’s normal behavior for this heightened emotional situation.

3. Allows the examiner to identify something he has in common with the subject, to establish rapport.

4. It minimizes resistance.

2. Symptomatic Question = is designed to ensure that the examiner will not ask un-reviewed questions or that the examinee is not afraid that the examiner will ask un-reviewed questions.

Examples:

n  Do you believe me when I promised not to ask a question in this test I have not gone over word for word?

n  Even though I promised I would not, are you afraid I will ask a question in this test I have not gone over word for word?

3. Sacrifice Relevant Question = it introduces the relevant question to the subject

            = designed to absorb the response generated by the introduction of relevant question in the series

Example:

n  Regarding the (matter under investigation), are you willing to answer the questions truthfully?

4. Relevant Question = a question deals with the matter under investigation. Color coded red in computerized instruments. It is designed to generate reactions from deceptive subject.

Types of Relevant Question

a. Primary Relevant (Strong Relevant) = addresses the primary issue or direct involvement of the subject on the matter under question. It is use primarily with the single-issue examination.

n  Ex. Did you take that missing money?

b. Secondary Relevant (Weak Relevant) = deals with the physical acts that support the primary issue. This is usually use in multi-issue examination.

n  Ex. Did you participate in the theft of that missing money?

c. Guilty Knowledge = designed to probe whether the subject possesses information regarding the identity of the offender or the facts of the case under question.

n  Ex. Do you know who took that missing money?

d. Evidence Connecting Question = test question in which the examinee is asked about a particular piece of physical evidence that would incriminate the guilty person. It could be items left at the crime scene by the perpetrator or stolen property.

n  Ex. Do you know where any of that missing money is right now?

5. Comparison Question = a question which is the same in nature with that of the relevant question but broad in scope.

            = is used for comparative purposes with the relevant question.

            = designed to generate reactions from truthful subject.

Types of Comparison Question

a. Directed Lie Comparison Question (DLC) = a comparison question in which the examinee is instructed by the examiner to answer the questions untruthfully. 

                        Some examiners actually get admission to comparison questions and then instruct the examinee to lie to that question when it is asked.

b. Probable Lie Comparison Question (PLC) = a question to which it is likely that the examinee is untruthful with his answer.

            = PLC questions are broad in scope and usually based on actions categorically similar to that of the issue under investigation

Types of Probable Lie

a. Inclusive =  a comparison question which include the relevant time period under investigation. It was originally designed by Reid.

            = this type of question usually starts with the phrase: “In your entire life,…..”. Also termed as inclusionary.

                       

b. Exclusive = a comparison question separated in time, place and category from the relevant question. It was introduced by Cleve Backster. He believes that this prevents the guilty suspect from perceiving the comparison question as an ambiguous relevant question.

Example:

n  During the first __ years of your life, did you ever ____?

n  Prior to 2009, did you ever _____ ?

n  While in college ______?

n  Between the ages of __ & __, did you ever _____?

Types of Polygraph Technique/Test

1. General Question Test = consist of series of relevant, irrelevant control questions in a planned order. Developed by John E. Reid

2. Relevant/Irrelevant Test = consists primarily of series of irrelevant questions and relevant question pertaining to the crime under investigation. Developed by Keeler.

3. Peak of Tension Test = consist of only one relevant and a series of irrelevant questions.

            = resemble, in every general way, the card test, for it consist essentially of the asking of a series of question in which only one has any bearing upon the matter under investigation.

            = padding questions before and after the relevant questions.

Two Types of POT Test

n  Known Solution Peak of Tension Test (KSPOT) = is used to determine whether the examinee is aware of details of a crime that have been kept from the general public and would presumably only be known to the perpetrator of the crime or those with incriminating knowledge.

n  Searching Peak of Tension Test (SPOT) = is used to determine details of a crime that are not known to officials, such as the location of an unrecovered body, but would be known to a participant in the crime.

4. Card test / Acquaintance Test / Stimulation Test = the subject is presented with seven (7) previously numbered cards face down.

= he will be instructed to take one, look at it and return it with the rest of the cards.

            = the examiner will shuffle the cards and each card will be shown to him, with the instruction that he will answer “NO” to all cards , even  if the one being shown to him is the one he has seen earlier.

5. Guilt Complex Test = used primarily for overly responsive subjects.

            = a totally fictitious incident but a similar nature to the matter being investigated and make him believe it is real.

            = The purpose is to compare the response with those response made concerning the actual matter under investigation

6. Silent Answer Test = Subject is instructed not to give any verbal answer, the subject will only answer in his mind.

7. Comparison Question Test (CQT) = the reactions on the control and relevant questions are compared via numerical scoring

Polygraph Examiner = is one who is capable of detecting deception and verifying the truthfulness of statement through the use of a polygraph instrument.

            = is someone who has successfully completed formal education and training in conducting polygraph examination and is certified by his agency to conduct such examination.

Subject = is any person who undergoes polygraph examination.

Polygraph Examination = a process that encompasses all activities that take place between a polygraph examiner and an examinee during a specific series of interactions. For a valid polygraph examination to exist, respiration, EDA, and Cardiovascular activity must be monitored and recorded.

Two Types of Polygraph Exam

1. Mixed Issue Exam = multiple-issue polygraph testing like screening of applicants or audit of employees or persons with security clearances.

2. Diagnostic Exam = a test which involves specific case investigation.

Types of Diagnostic Exam

1. Single Issue Exam = a test which inquires direct involvement of subject into a specific case under question.

2. Mult-facet Exam = test format in which the relevant questions are targeted toward different elements of the same crime.

Stages in the Conduct of the Polygraph Test

n  Initial Interview With the Investigator

1. Pre-test Interview = an interview conducted by the polygraph examiner designed to prepare or condition the subject for the actual test.  It usually last for about 20 – 30 minutes

a. Determining the subject physical, mental and psychological suitability to undergo the test

                        a.1.  the subject should avoid taking drugs at least 12 hrs before the test

                        a.2. the subject if female should not be pregnant

                        a.3. the subject should not be hungry

                        a.4. the subject should not be physically or emotional abuse

                        a.5. the subject should not be suffering high blood or hypertension.

b. Informing the subject of his Constitutional Rights (if the examiner is a law enforcement officer)

c. Taking of the subject consent

d. Taking of the subject personal data

e. Discuss with the subject the crime/issue under investigation

f. Preparing the subject for the test – administration of stimulation test

2. ln-Test (Actual Test) = is the actual conduct of the test administered by a polygraph examiner

Conditions of the Room

n  It should be spacious for two persons

n  Well lighted

n  Well ventilated

n  Sound Proof

n  Not decorated

3. Post-test Interview or Interrogation =  is an interview or an interrogation administered by a polygraph examiner after the test designed to obtain confession or admission by the subject.  = interview is conducted when the reactions indicate an innocent response and very cooperative to the examiner.  = interrogation is conducted when the reactions show sign of deception and being uncooperative to open an information.

Chart markings = are annotations of the physiologic tracings to denote stimulus (question) onset and offset, examinee’s answer, question number, question label, artifacts, and other details important to the interpretation of the physiological data.

Two Types Chart Markings

1. Primary Markings = these are markings which indicate the beginning and end of examination as well as the questions and answers of the subject. These are usually placed at the bottom or top of the polygraph chart

1. X – it indicates the start of the test. The examiner informs the subject that the test is about to begin.

2. I    I – is a stimulus mark. The first vertical line marks when the examiner starts asking question. Second vertical line marks when the examiner finishes asking question.

3. + - a positive sign which indicates that the subject answers the question with “yes”. This also indicates the period when the subject answers the question and usually followed by a “number” indicating the order number of question, example +3, +4, +5….)

4. – a negative sign indicating that the subject answers the stimulus with “no”. This also indicates the period when the subject answers the question and usually followed by a “number”.

5. XX – indicates the end of test.

2. Secondary Markings = are markings which are placed only if the examinee does something which will cause the physiological tracings to distort. These markings are usually placed below the affected tracing.

1. M – Movement
2. T – Talking
3. DB – Deep Breath
4. C – Cough
5. CT – Clear Throat
6. SW – Swallow
7. SNF – Sniff
8. Y – Yawn
9. SZ – Sneeze
10. LGH – Laugh
11. SLP – Sleep
12. B – Belch
13. OSN – Outside Noise
14. ISN – Inside Noise
15. EE – Examiner Error
16. WRQ – Will Repeat Question
17. MI – Movement Instruction
18. TI – Talking Instruction
19. AI – Answering Instruction
20. BI – Breathing Instruction
21. WU – Wake-Up
22. TDB – Take Deep Breath

INTERPRETATION OF POLYGRAPH DATA

Important Terms to Consider

n  Analysis Spot = The relevant and control questions that are actually evaluated during spot analysis.

n  Artifact = A change in an examinee’s physiological pattern that is not attributable to a reviewed test question. It includes examinee’s movements during the examination.

n  Blind chart Analysis = Evaluation of PDD recordings without the benefit of extrapolygraphic information, such as subject behavior, case facts, pretest admissions, base rates of deception, etc

n  Deception Indicated (DI) =  A decision of DI in PDD means that (1) the physiological data are stable and interpretable, and (2) the evaluation criteria used by the examiner led him to conclude that the examinee is not wholly truthful to the relevant issue.

n  Exosomatic = Something generated from outside the body.  Skin resistance is exosomatic measures because electrical current is applied from outside sources to detect the electrodermal activity.

n  EDA Recovery Phase = The physiological activity displayed in an EDA tracing that occurs between the highest peak and subsequent return to the pre-stimulus or newly established baseline. The EDA recovery phase begins once the tracing ahs reached its highest peak.

n  EDA Rise Time = The physiological activity displayed in an EDA tracing beginning with response onset and ending at the peak.

n  No Deception Indicated (NDI) = is a conventional term in PDD, NDI signifies that the polygraph test recordings are stable and interpretable and the evaluation criteria used by the examiner led him to conclude that the examinee was truthful to the relevant issue.

n  Test Data = The signal of interest that may consist of artifacts, recovery or examinee’s physiological response to stimuli.

n  Test Data Analysis = Analysis of the psychohysiological response activity (time) displayed between response onset. Typically, this is the time from response onset until return to the pre-stimulus (phasic response) or a newly established baseline (tonic) response.

n  Recovery = A deviation in polygraph tracing attributable to a physiological phenomenon occurring as a compensatory action after a response or an artifact.

n  Response = A physiological change that occurs following, and is attributable to the presentation of  applied stimulus.

n  Phasic Response = A known origin response to a specific stimulus that is generally seen as an upward movement from the baseline with subsequent return to the pre-stimulus or original baseline.

n  Tonic Response = A known origin response to a specific stimulus that is generally seen as a movement from the pre-stimulus baseline and establishment of a new baseline without returning to the pre-stimulus baseline.

n  Response Amplitude = The displayed physiological activity reflected in a polygraph tracing occurring between response onset and response peak (highest level from pre-stimulus baseline).

n  Response Duration = The physiological activity (time) displayed between response onset and offset. Typically, this is the time from response onset until return to the pre-stimulus baseline (phasic response) or a newly established baseline (tonic response).

n  Response Latency = The time between stimulus onset and response onset.

n  Response Onset = The first indication of change from the pre-stimulus level of physiological activity to an applied stimulus.

n  Response Onset Window = The period of time between stimulus onset (verbal presentation of question) and an examinee’s verbal answer to that stimulus.

n  Spot Analysis = The procedure wherein each component tracing is separately evaluated by comparing the response of a relevant question to the response of a comparison question.

n  Stimulus Onset = It is the beginning of the presentation of the first word of a question.

n  Tonic Level = It describes the examinee’s physiological response when resting. An examinee’s level of physiological activity occurring prior to stimulus onset. This is sometimes referred to as the resting or baseline activity level.

n  Zone = A concept coined by Cleve Backster. A zone is a twenty to thirty-five seconds block of polygraph chart time initiated by a question having a unique psychological focusing appeal to a predictable group of examinees

Two types of Chart Interpretation

n  Global Analysis

n  Numerical Scoring

n  Manual Numerical Scoring

n  Computer Scoring Algorithm

GLOBAL ANALYSIS

                        In global analysis, the examiner looks for significant reactions that occur repeatedly which is referred to as “Conspecnificance”. Conspecnificance is the consistency of reaction to a specific question with significant magnitude

n  NUMERICAL SCORING

                        The numerical scoring is a method of rendering polygraph decisions that are based exclusively on numeric values that have been assigned to physiological responses recorded during a structured polygraph examination

ELEMENTS OF SCORING SYSTEM

1. Reaction Features = are raw physiological data that a polygraph examiner should look into the polygraph chart for numerical interpretation. It can be scored using the seven position or three position rules. Only reactions on the relevant and comparison questions are scored during interpretation.

2. Transformations = In transforming physiological data, combine observations of reactions to relevant and control stimulus into a single value for each component and for each presentation of each of the target stimuli.

n  Red questions (relevant) are compared to Green question (control)

n  Assign a - score when there is a larger response to a relevant question

n  Assign a + score when there is a larger response to a control question

n  Different scoring systems used different scoring rules in assigning numerical value to particular reaction features on the relevant and comparison questions.

3. Decision Rules = determines when data meet the criteria for inclusion in a particular category.

            = final step in polygraph numerical scoring, producing decisions of Deception Indicated, No Deception Indicated, and Inconclusive.

            = artifacts such as deep breaths, coughs, movements, and physiological abnormalities (premature ventricular contractions) affect the quality of tracings for scoring. All these should not be scored.

ACCURACY AND RELIABILITY OF POLYGRAPH RESULTS

n  Accuracy = the condition or quality of being true, correct, or exact

n  = refers to validity (state or quality of being well founded).

Types of Validity

n  Face Validity = opinion or consensus of experts

n  Content Validity = selection of pertinent issues of inquiry

n  Predictive Validity = ability to predict a future outcome

n  Concurrent Validity = ability to identify what is already known

n  Convergent Validity – new info coincide with extant info

n  Divergent Validity – new info separates extant ideas

n  Construct Validity – meaningful defined and understandable relationships (correlations) between various phenomena

n  Criterion Validity – accuracy of category decisions

n  Incremental Validity – professional decision accuracy improves with the use of additional information

Reliability = refers to stability or consistency of measurement. Reliability studies in PDD often examine the rate of decision agreement among examiners on polygraph test charts.

Two Types of Reliability

1. Interrater reliability = denotes agreement among examiners

2. Intrarater agreement (test-retest reliability) = pertains to an examiner agreement with his own decisions when evaluating the charts on different occasions.

Note:

                        Reliability is not the same as validity, which means accuracy. A technique cannot be more valid than it is reliable. A technique can have high agreement without high accuracy, though the reverse is not true.

Goals of Polygraph Testing

n  Sensitivity = Ability to detect or notice the issue.

n  Specificity = Ability to reject non-involved cases.

Threshold of Accuracy According to American Society for Testing Materials (ASTM)

n  Ninety (90) Percent = for evidentiary polygraph examinations. Evidentiary polygraph examinations are those conducted specifically for courtroom purposes.

n  Eighty (80) Percent = for investigative polygraph examination. Investigative polygraph examinations are used for non-judicial purposes.

n  Both evidentiary and investigative examinations are permitted to an inconclusive rate of twenty (20) percent.

Result Errors

n  False Negative = refers to the failure to detect the presence of a particular event or item.

= in polygraphy refers to the incorrect decision that deception was not practiced by the examinee.

n  False Positive = is the false detection of something that is not actually present. In polygraphy

            = it is the incorrect decision that deception was practiced by the examinee.

Admissibility of Result

            In the Philippines, polygraph results are not admitted as evidence. Many polygraph examiners and lawyers have attempted presenting polygraph evidence in court but all resulted to futile.

Philippines

n  Rule 130 section 49 of the Rules on Evidence provides that:

                         “The opinion of a witness on matter requiring special knowledge, skill, experience or training which he shown to posses, may be received in evidence.”

U.S. United States v. Frye – 1923 – NOT ADMITTED AS EVIDENCE (First case in Polygraphy)

 

Daubert v. Merrell Dow Pharmaceuticals - 1993 (U.S.)

Areas of Inquiry:

n  the theory or technique in question can be (and has been) tested;

n  whether it has been subjected to peer review and publication;

n  its known or potential error rate; 

n  the existence and maintenance of standards controlling its operation; and

n  whether it has attracted widespread acceptance within a relevant scientific community.

In New Mexico, the Supreme Court, in State v. Dorsey in 1973, ruled that:

                       

                        “Polygraph results are admissible as long as (1) the polygraph operator is competent, (2) the procedure used is reliable, and (3) the “tests made on the subject” are valid.”

In 1983, New Mexico then codified the admissibility of polygraph results with Rules of Evidence, which states that:

                        "Subject to the provisions of these rules, the opinion of a polygraph examiner may in the discretion of the trial judge be admitted as evidence as to the truthfulness of any person called as a witness if the examination was performed by a person who is qualified as an expert polygraph examiner.”