POLYGRAPHY

INTRODUCTION:
The idea of using a polygraph for lie detection emerged at the end of the nineteenth century. Despite major technological advances in the twentieth century, the polygraph has evolved little since its invention. The polygraph works under the assumption that lies can be detected by certain measurable physiological changes, a theory proposed more than 100 years ago. The three physiological vectors measured in polygraphs in the 1920s cardiovascular, respiratory and perspiratory activities are still measured by modern polygraphs. Although the polygraph is still widely used, critics question its accuracy because of the subjectivity involved in the test. Recent technological breakthroughs have created new machines for lie detection. However, since many of these new technologies still operate under questionable assumptions, they are still prone to error and misinterpretation.

Perhaps one of the most fascinating and misunderstood tools of the criminal justice and criminology industry is the polygraph exam, more commonly known as the lie detector test. While the tests are based on relatively simple scientific principles, not just anyone can strap you up to an instrument and start firing away with questions. Lie detector tests are instead conducted by highly trained and disciplined technicians, known as polygraph examiners.

LIE DETECTION AND FORENSIC PSYCHOPHYSIOLOGY * Lie Detection * It is also referred to as deception detection which uses questioning techniques along with technology that record physiological functions to ascertain truth and falsehood in response. It is commonly used by law enforcement and has historically been an inexact science. There are a wide variety of technologies available for this purpose. The most common and long used measure is the polygraph, which the U.S. National Academy of Sciences states, in populations untrained in countermeasures, can discriminate lying from truth telling at rates above chance, though below perfection. They added that the results apply only to specific events and not to screening, where it is assumed that the polygraph works less well.

* Psychophysiology * Psychophysiology (from Greek ψῡχή, psȳkhē, "breath, life, soul"; φύσις, physis, "nature, origin"; and -λογία, -logia) is the branch of psychology that is concerned with the physiological bases of psychological processes. While psychophysiology was a general broad field of research in the 1960s and 1970s, it has now become quite specialized, and has branched into sub specializations. For example, social psychophysiology, cardiovascular psychophysiology, cognitive psychophysiology, and cognitive neuroscience.

* Forensic Psychophysiological Detection of Deception (PDD): * The science that deals with the relationship and applications of PDD tests within the legal system. It is the academic discipline that provides the student, the practitioner, and the researcher with the theoretical and applied psychological, physiological, and psychophysiological fundamentals for a thorough understanding of PDD tests, and the skills and qualifications for conducting PDD examinations. The modifier "forensic" delineates and delimits this discipline from the broader discipline of psychophysiology.

* Polygraph * The term "polygraph" literally means "many writings." It refers to the science of the test, in which several physiological responses are measured at the same time to detect signs of deception. This process is called forensic psychophysiology, which denotes the relationship to the mind and the body as it pertains to physical responses to thoughts and emotions. The true professional title of a polygraph examiner, then, is forensic psychophysiologist. * Polygraphs usually termed, as “lie detector” is an instrument that monitors a person’s physiological reactions. This instrument does not detect lies. It can only detect whether deceptive behavior is being displayed. * The instrument is carefully and accurately engineered for recording changes in the respiration, skin moisture, blood pressure and pulse. The polygraph chart tracing will reveal attempted deception as shown by physiological changes that are recorded reliably.

* Components of a Polygraph:
1. PNEUMOGRAPH - The pneumograph records changes of breathing of the subject it consists of transducers and pneumograph tubes which are fastened around the subject’s abdominal and thoracic part of the body.
2. GALVANOGRAPH - Records the skin resistance of the subject to a very small amount of electricity.
3. CARDIOSPHYMOGRAPH - The cardiosphymograph records the changes of blood pressure and pulse rate it is consists of arm cuff.
4. KYMOGRAPH – is sometimes referred as a chart drive module.

* Concepts of Polygraph Examination
a. Used to test an individual for the purpose of detecting deception or verify the truth of statement.
b. Records identifiable physiological reactions of the subject, such as high blood pressure, pulse rate, respiration, and skin resistance.
c. The effectiveness of the polygraph in recording symptoms of deception is based on the theory that a conscious mental effort on the part of a normal person to deceive, causes involuntary physiological changes which are in effect a body’s reaction to an imminent danger to its well-being.

* Objectives of Polygraph Examination
a. Obtain additional investigative aid which leads to the facts of the case/offense.
b. Ascertain if a person is telling the truth.
c. Locate the fruits or tools of the crime or whereabouts of wanted persons.
d. Identify other persons involved.
e. Obtain valuable information from reluctant witnesses.
f. Eliminate the innocent suspects.

* Principal Uses of the Polygraph
a. Aid in investigation.
b. Speeds up processing of investigation.
c. Eliminates innocent suspects.
d. Pre-employment screening.
e. Honesty test (periodic test).

* Limitations of the Polygraph
a. It is an invaluable investigative aid; but never a substitute for an investigation.
b. It is not a lie detector; it is a scientific diagnostic instrument.
c. It does not determine facts; it records only responses of the subject.
d. It is only as accurate as the examiner is competent.
e. It record response which the subject knows to be truth.
f. The test will not be given until enough facts of the case have been established to permit as examiner to prepare complete sets of suitable questions.
g. A test will not be given without voluntary consent of the subject.
h. No indication will be given to any person or place in any report that a person will be considered guilty because he refuse to take the test.
i. A test will not be given until the accusations have been explained to the subject.
j. No attempt to use polygraph for mental or physical evaluation of any person.
k. No examination can be conducted to an unfit subject.

SCIENTIFIC METHOD OF DETECTING DECEPTION
Most of the test are not reliable to be true and thus the information gathered are not admissible in court as evidence but only important to be used for further investigation. * Lie Detector Test
A test used to record the physiological change associated with lying subject. The polygraph machine will record the blood pressure, respiratory rate and the skin resistance to electricity in a chart paper.
In business and industry, the device is used to inquire deliberate falsification of application and other document, elicit use of drugs, and thefts of money or merchandize from the previous employers.
Despite of drawbacks and unreliable result that it may not be admissible in court, modification and improvements in the machine have been done. In some countries in the United State, the result of the test as evidence is steadily moving toward the direction of admissibility in court. While the Philippines, it is still not admissible in court. * Administration of Truth Serum or Narco-analysis
This is detecting deception method using narcotic or anesthetic drug in order to get information from the subject. The following are drug used (truth serum) Hyocine hydro-bromide; Sodium amytal; Penthotal; Seconal and other barbiturates; Methedrine; Methyl phenidate; Droperidol; Scopolamine; Trichloroethylene (anesthetic drugs); etc.
Unreliable results. The information gathered from the subject is not reliable to be true. The information taken from the subject under narcosis is not admissible in court as evidence. Although not admissible, it is quite useful for further investigation. * Use of Alcoholic Beverage
The subject is to forget alibis and sometimes unveiling the secrets of crime.
The information taken from the subject under the influence of alcohol is also not admissible in court as evidence because of the involuntary condition of the subject, however, it may be admissible if the subject can recall his statement when he was under the influence of alcohol when confronted again. * Stimulus Association Test
In this test, the subject will be interviewed, wherein a group of stimulus words or persons will be presented to the subject.
The interrogator will study the time interval and the reaction of the subject.
This test is also not reliable as a deception detection method because of the following reasons:

a. A person likes the recidivist and really guilty may defeat the test by telling lies.
b. Sometimes, the test requires the use of intelligence in answering questions.
c. A nervous person who is innocent may have a long time interval in answering questions and may even have signs and symptoms. * Use of Hypnotism
The hypnotism finds its way in criminal investigation by hypnotizing the subject and then questions will be asked when the subject is under hypnosis. The subject is under the control and influence by the hypnotist and therefore the information gathered is devoid of the subject’s own freewill to speak making it not admissible in court.

RECENT PRACTICES IN LIE DETECTION 1. Event-related potentials (ERP):
It assess recognition, and therefore may or may not be effective in assessing deception. In ERP studies P3 amplitude waves are assessed, with these waves being large when an item is recognized. However, P100 amplitudes have been observed to have significant correlation to trustworthiness ratings, which the importance of will be discussed in the EEG section. This, along with other studies leads some to purport that because ERP studies rely on quick perceptual processes they "are integral to the detection of deception.

Compared with behavioral procedures, ERPs provide a continuous measure of processing between a stimulus and a response, making it possible to determine which stage(s) are being affected by a specific experimental manipulation. Another advantage over behavioral measures is that they can provide a measure of processing of stimuli even when there is no behavioral change. However, because of the significantly small size of an ERP, it usually takes a large sample size to accurately measure it correctly.

2. Electroencephalography (EEG):
It measures brain activity through electrodes attached to the scalp of a subject. The object is to identify the recognition of meaningful data through this activity. Images or objects are shown to the subject while questioning techniques are implemented to determine recognition. This can include crime scene images, for example.

EEGs can detect changes over milliseconds, which is excellent considering an action potential takes approximately 0.5-130 milliseconds to propagate across a single neuron, depending on the type of neuron. Other methods of looking at brain activity, such as PET and fMRI have time resolution between seconds and minutes. EEG measures the brain's electrical activity directly, while other methods record changes in blood flow (e.g., SPECT, fMRI) or metabolic activity (e.g., PET, NIRS), which are indirect markers of brain electrical activity.

EEG can detect covert processing (i.e., processing that does not require a response). EEG can be used in subjects who are incapable of making a motor response. Some ERP components can be detected even when the subject is not attending to the stimuli. Unlike other means of studying reaction time, ERPs can elucidate stages of processing (rather than just the final end result).

3. Facial electromyography (fEMG):
This refers to an electromyography (EMG) technique that measures muscle activity by detecting and amplifying the tiny electrical impulses that are generated by muscle fibers when they contract. It primarily focuses on two major muscle groups in the face, the corrugator supercilii group which is associated with frowning and the zygomaticus major muscle group which is associated with smiling.

Facial EMG has been studied to assess its utility as a tool for measuring emotional reaction. Studies have found that activity of the corrugator muscle, which lowers the eyebrow and is involved in producing frowns, varies inversely with the emotional valence of presented stimuli and reports of mood state. Activity of the zygomatic major muscle, which controls smiling, is said to be positively associated with positive emotional stimuli and positive mood state. Facial EMG has been used as a technique to distinguish and track positive and negative emotional reactions to a stimulus as they occur.

4. Eye-tracking:
John Kircher, Doug Hacker, Anne Cook, Dan Woltz and David Raskin have developed eye-tracking technology at the University of Utah that they consider a polygraph alternative. This is not an emotional reaction like the polygraph and other methods but rather a cognitive reaction. This technology measures pupil dilation, response time, reading and rereading time, and errors. Data is recorded while subjects answer true false questions on a computer.

They have found that more effort is required by lying than giving the truth and thus their aim to find indications of hard work. Individuals not telling the truth might, for instance, have dilated pupils while also taking longer to answer the question. Eye-tracking offers several benefits over the polygraph: lower cost, 1/5th of the time to conduct, subjects do not need to be "hooked up" to anything, and it does not require qualified polygraph examiners to give the test.

5. Voice risk analysis or Voice stress analysis (VSA):
This uses computers to compare pitch, frequency, and intensity and micro tremors. In this way voice analysis "detect minute variations in the voice thought to signal lying."

Software then compares control questions to relevant questions assessed for deception. However, its reliability has been debated by peer-reviewed journals. "When a person lies, an involuntary interference of the nerves causes the vocal cords to produce a distorted sound wave, namely a frequency level which is different from the one produced by the same person when telling the truth."

Recently conducted studies have however, identified that the detection of deception is possible with the use of voice stress analysis software loaded onto a laptop computer. In a study published December 7, 2013, the International Journal of Electrical, Electronics and Computer Engineering (IJEECE) found that Voice Stress Analysis (VSA) technology can identify emotional stress better than polygraph.

6. Functional magnetic resonance imaging (fMRI)
It is a technique used for multiple purposes which shows the uses of oxygen by the brain, allowing for the identification of which portions of the brain are using more oxygen, and thus being used during a specific task. This is called the Blood Oxygen Level Dependent or BOLD hemodynamic response.

Studies using functional magnetic resonance imaging (fMRI) have shown that it has potential to be used as a method of lie detection. While a polygraph detects changes in activity in the peripheral nervous system, fMRI has the potential to catch the lie at the 'source'. To use an MRI as a lie detector, an fMRI should be used by placing a magnetic band as a scanner on a subject's head. However, the neurobiological systems that relate to lying are currently poorly understood. The current consensus is that faced with a forced choice paradigm, in which a subject has the choice of telling the truth or spontaneously generating a lie, lying can be distinguished due to increased prefrontal and parietal lobe activity. More specifically, the superior medial and inferolateral prefrontal cortices show net activation in the process of spontaneous lie generation (which involves suppression of the truthful response as well as generating a conceivable lie). There also is evidence of increased activation in the anterior cingulate cortex when lies are told.

7. Functional near-infrared spectroscopy
It also detects oxygen and activity in the brain like the fMRI, but instead it looks at blood oxygen levels. It is advantageous to the fMRI because it is portable, however its image resolution is of less quality than the fMRI.

FNIR has several advantages in cost and portability over fMRI, but cannot be used to measure cortical activity more than 4 cm deep due to limitations in light emitter power and has more limited spatial resolution.

8. Cognitive polygraph
Recent developments that permit non-invasive monitoring using functional transcranial Doppler (fTCD) technique showed that successful problem-solving employs a discrete knowledge strategy (DKS) that selects neural pathways represented in one hemisphere, while unsuccessful outcome implicates a non-discrete knowledge strategy (nDKS).

A pattern of blood-flow-velocity changes is obtained in response to questions that include correct and incorrect answers. The wrong answer will elicit bi-hemispheric activation, from correct answer that activates unilateral response. Cognitive polygraphy based on this system is devoid of any subjective control of mental processes and, hence, high reliability and specificity; however, this is yet to be tested in forensic practice.

LEGALITY OF POLYGRAPHY

a. Polygraph test is an invaluable aid in investigation. If a subject agrees to voluntarily submit to take the test and it is properly conducted, his rights are not violated.
b. No polygraph test can be effectively employed on an unwilling subject. The charts derived there from would be indicative more of bodily movements, silence and anger rather than an objective basis for an opinion of lying; hence, voluntary consent is essential.
c. Generally, the opinions rendered by the polygraph examiner on the test charts are not acceptable as evidence particularly if standing alone. The examiner may however testify on the voluntariness of any statement, admission or confession obtained after an individual agreed to the test.
d. Rejection of the lie detector test is not based upon the inaccuracy of the instrument but rather towards the weakness of the examiner and the subject as well, as to the query whether the test questions are sound or not.
e. The question as to whether the polygraph is perfect is equivalent as to whether a clinical thermometer, stethoscope, x-ray machine or compound microscope is perfect. A trained scientist maybe mistaken in what he sees or hears by any of these devices. Like the thermometer and the stethoscope, the polygraph is simply an instrument for recording physiological reactions and it is possible for the examiner to be mistaken in his interpretation of the recording. Even in the best of clinics, the interpretation is not 100% accurate, but that does not imply that the machine should not be used. The same can be said for the polygraph.
f. In every case not substantiated by a valid confession, or other definite evidence, any conclusion based solely upon the analysis of the polygraph charts, constitutes an opinion and in direct proportion to the expertise and integrity of the examiner.
g. Those who will oppose the use of the examiner’s report in the courtroom do so mainly on the question of its accuracy. Aside from the certain psychological considerations, they blame this inaccuracy of the failure of examiners to used uniform procedures in the conduct of the test.
h. It is the experience of most courts that the great majority of trials on issue of guilt or innocence; turn on the credibility of the witness. Perjury is prevalent and the oath taken by the witness has little effect to deter false testimony. The principal role of the trier of facts is the search for truth and any reasonable procedure or method to assist the court in this search must be employed.
i. Police, prosecutors and polygraph examiners, feels that the results of polygraph examination should be admitted only insofar as they tend to prove or disprove the credibility of witness. The examiner should not be allowed to testify as the guilt or innocence of the subject, but limit his testimony to the issue of credibility based upon the subject’s body responses to the questions asked.
j. Polygraph test results and expert testimony relating thereto can be admissible upon stipulation to corroborate other evidences of a defendant’s participation to the crime charged or to corroborate or impeach his own testimony under the following conditions:
j.1. the counsel of both parties and the subject, will sign a written stipulation providing for subject’s submission to the test and for the subsequent admission at the trial of the graphs and the examiner’s opinion thereon, on behalf of either the defendant or the state.
j.2. that the admissibility of the test results is subject to the discretion of the trial judge. If the trial judge is not convinced that the examiner is qualified or that the test was conducted under improper conditions, he may refuse to accept such evidence.
j.3. If the graphs and examiner’s opinion are offered in evidence, the opposing party shall have the right to cross-examine the examiner respecting among others, the following:
j.3.a. The examiner’s qualification and training.
j.3.b. The conditions under which the test was administered.
j.3.c. The limitations of and possibilities for error in the technique, and
j.3.d. Other matters deemed pertinent to inquire at the discretion of the trial judge.

k. The polygraph now enjoys general acceptance among authorities including psychologists, physiologists, researchers in these fields as well as polygraph examiners, because it now possess a high degree of reliability and validity as an effective instrument and procedure for detecting deception.

REFERENCES:

Matte, James Allan. Forensic Psychophysiology Using the Polygraph. JAM Publications. New York. 1996.

Lajom, Fidel P. Criminalistics. Manila. Rex Bookstore. 1998

Tradio, Cirilo M. Compendium on Criminalistics. Manila. Central Law Book. Inc., 1997.

Batalang, Antonio M. Lie Detection and Interrogation. (Unpublished). Baguio Colleges Foundation, Baguio City. 2000

Detran, Rose Marie C. Notes in Lie Detection. (Unpublished). University of Baguio, Baguio City. 2013

https://en.wikipedia.org/wiki/Lie_detection http://www.policepolygraph.org/standards.htm https://antipolygraph.org/documents/federal-polygraph-handbook-02-10-2006.pdf https://en.wikipedia.org/wiki/Psychophysiology http://www.nap.edu/read/10420/chapter/8