Terms Relating to Lie Detectors Explained – Letter P
P300Event-related potential (ERP) of the brain measured at the scalp that hasan average latency of 300 milliseconds from stimulus onset and is recordedmaximally at site PZ in the International 10-20 System. The P300 is related tounique characteristics of the stimulus, and is most often associated with the“oddball” or rarely occurring stimulus. For example, the P300 is known to beevoked by a low incidence auditory tone that is of a different pitch than anothertone that is occurring much more frequently. A P300-based ConcealedInformation Test has been developed for criminal testing, though field testing isincomplete. See: Farwell & Donchin (1991); MacLaren & Taukulis (2000);Rosenfeld (1998).PaddingAn alternate expression for irrelevant items in a Known Solution Peak ofTension test. In some reports, padding relates to only the first or last one ortwo items in these tests.Pain CountermeasureSpecial type of physical countermeasure in which an examinee willattempt to evoke physiologic responses by covertly self-inducing discomfort.Included in this group are strategies such as biting the tongue, pressingagainst a sharp object in the shoe, forcing a fingernail into the thumb cuticle,and irritating a wound. While spontaneous use of these tactics has not beenfound effective, they can be more powerful when the examinee receives trainingand feedback. See: Honts, Raskin & Kircher (1994); Krapohl (1996).ParameterTerm used in PDD to denote a single physiological data channel, such asthe pneumograph, cardiograph, etc.ParadigmExample or model. Experimental paradigms attempt to explain realworld phenomena by assessing the critical elements and their relationshipswith one another.Parasympathetic Nervous SystemOne of the three divisions of the autonomic nervous system also referredto as the craniosacral system because the preganglionic neurons lie in thoseareas. Parasympathetic ganglia anatomically lie in or near the organs theyinnervate thus allowing for more localized control. Functionally, it is involvedin conservation and restoration of energy. The parasympathetic andsympathetic divisions of the autonomic nervous system function to maintainhomeostasis.ParasympathomimeticAn agent whose effects mimic those resulting from stimulation ofparasympathetic nerves, especially those produced by acetylcholine.PathometerDevice used by Rev. Walter Summers to perform deception tests in the1930s. Researchers had to order Pathometers from Fordham University, andthey were only assembled upon order. Summers conducted testing onhundreds of subjects using this recording galvanometer and a testingprocedure he devised that included what would be later known as comparisonquestions. See: Summers (1939).Peak of Tension (POT)Family of recognition testing procedures, including known solution,searching (probing), concealed information and stimulation tests. A KnownSolution POT (KSPOT) is used to determine whether the examinee is aware ofdetails of a crime that have been kept from the general public and wouldpresumably only be known to the perpetrator of the crime or those withincriminating knowledge. A Searching POT (SPOT) is used to determine detailsof a crime that are not known to officials, such as the location of anunrecovered body, but would be known to a participant in the crime. TheConcealed Information Test can be used in either the known solution orsearching condition, and is differentiated from the former two tests primarily onthe number of tests given, and the random placement of the critical item in thetest list. Stimulation tests come in several varieties and are covered in moredetail under that heading. The evaluation criterion of Peak of Tension stripcharts is simply identifying the point in the tracings where physiologic arousalhas peaked, hence the name. Peak of Tension tests are not generally used todetermine truth or deception, but rather to assist in the investigation orinterrogation.Pearson product-moment correlationA test of correlation between two sets of interval level data (see scale ofdata). The coefficients will lie between -1 and +1. A value of 0 would indicateno correlation, while -1 and +1 would mean perfect negative and positivecorrelations, respectively.Penile PlethysmographA device that measures penile engorgement resulting fromvasocongestion, sometimes used in psychological evaluation of sex offenders.The reliability and validity of this procedure in clinical assessment have notbeen well established, and clinical experience suggests that subjects cansimulate response by manipulating mental images. See: DSM-IV p. 524.Pen starterSuction bulb with plastic tube used to draw ink from the reservoir,through the pen, to the pen tip. Used on old analog polygraphs withcommunity ink systems.Peripheral Nervous SystemPortion of the nervous system resident primarily outside of the brain andspinal cord. The cell bodies of the preganglionic sympathetic neurons lie in the spinal cord and those of the parasympathetic branch are situated in the brainstem.Pertinent QuestionRarely used term for relevant question.PG1Computer polygraph manufactured in the Peoples Republic of China.The designation of “PG” by the Chinese was for “polygraph” in English.PhalanxAny bone of the fingers and toes. In research and as commonlypracticed in PDD, electrodermal sensors are attached to the distal phalanx, orend of the finger tips. Plural is phalanges.Pharmacological CountermeasuresClass of countermeasures in which the examinee attempts to affect thepolygraph recordings through the use of ingested drugs or application of topicalpreparations. See: Krapohl (1996).Phasic ResponseA relatively rapid reaction, characterized by a relatively rapid changefrom and return toward baseline.Photoplethysmograph (PPG)The PPG uses the reflection of a red light emitted into the skin to detectchanges in the volume of blood in the upper layers of skin, typically recorded atthe finger when using a polygraph. Physiological arousal is marked by aconstriction in the pulse amplitude as blood is shunted from the extremityduring activation of the sympathetic nervous system. See: Geddes (1974);Hander & Krapohl (2007); Kircher & Raskin (1988).PhotopolygraphA polygraph created by C.W. Darrow in the 1930s. It was one of themost elaborate polygraphs of that era, recording relative blood pressure, skinresistance, respiration, reaction time, and bilateral hand tremors. It had twostimulus markers, one activated by hand and the other was a voice key.Costing upwards of $2,000 and requiring a separate technician to operate,Darrow’s photopolygraph was primarily a laboratory instrument and was notused extensively by the PDD community. Also called the DarrowPhotopolygraph. See: Darrow (1932).Physical CountermeasuresClass of countermeasures in which the examinee attempts to manipulatethe polygraph recordings through the discreet use of movements. Some ofthese movements are also used to self-induce pain. See: Honts (1987);Krapohl (1996).PIK-02Computer polygraph developed and manufactured in Russia. It recordselectrodermal activity, vasomotor activity, blood volume, thoracic andabdominal breathing, motor tremor, and speech. The company URL is:http://www.liedetector.ru/.Pilomotor ResponseContraction of the piloerector muscles in the skin that erects hairs andproduces “goose flesh.” One of the symptoms of a sympathetic nervous systemactivation. Sometimes called piloerection.Pinocchio responseNonexistent lie-specific physiological response. The expressionsometimes used by polygraph critics to deride the notion that the act ofdeception produces stereotypical physiological response patterns.PlaceboProcedure or substance with no intrinsic effect but is useful to convincethe patient or subject that an effective treatment has been applied. Placebosoften have effects that are attributable to suggestion. They are usedextensively in medical research for control purposes during drug testing and forcertain psychosomatic illnesses. In PDD it addresses one type of mentalcountermeasure whereby examinees use ritual objects, incantations, or otherineffectual actions with the expectation that the power of the polygraph touncover deception will be impeded.PlethysmographA device used to measure relative changes in blood volume and pulsevolume. The three most commonly used are (a) changes recorded using astrain gauge, (b) impedance changes and (c) photoelectric changes. It is thethird technique that is used in modern polygraphy to measure the relativechanges in pulse volume associated with the vasomotor response, usually atthe distal phalange of one of the examinee’s fingers.PneumographA device that records respiration, and one of the three traditionalchannels of the modern polygraph used in PDD. Most contemporarypolygraphs use two pneumograph recordings: abdominal and thoracic. Thetypes of sensors include the traditional corrugated rubber tube, the mercurystrain gauge, or the newer piezoelectric.PolygraphBy definition, an instrument that simultaneously records two or morechannels of data. The term now most commonly signifies the instrument andtechniques used in the psychophysiological detection of deception, thoughpolygraphs are also used in research in other sciences. In PDD the polygraphtraditionally records physiologic activity with four sensors: blood pressure cuff,electrodermal sensors, and two respiration sensors. Some instruments alsorecord finger pulse amplitude using a PPG. Polygraph SurveillanceSee maintenance polygraph examination.PolygramComplete graphical recording of physiological data from a polygraph test,with the required annotations. Usually called a polygraph chart.Positive Control PairThe combination of the subjective truth question and the subjective liequestion, to form a set in the Positive Control Technique. See: Driscoll, Honts& Jones (1987); Gordon & Cochetti (1982); Howland (1981); Reali (1978).Positive Comparison QuestionIn the Positive Control Technique, each question is presented to theexaminee twice in a row, and the examinee is instructed to answer differentlythe first time from the second time. Therefore, each question serves as its owncomparison question. See: Driscoll, Honts & Jones (1987); Gordon & Cochetti(1982); Howland (1981); Reali (1978).Positive Control TechniqueTechnique that employs most of the standard test questions except aprobable-lie comparison questions, and each question is presented twice insuccession during the testing. The examinee is instructed to answer truthfullyto the first presentation, and untruthfully the second time, or vice versa. Whilethe technique is amenable to the 7-position scoring, it has its own unique setof decision rules that are different from the more familiar comparison questionformats. The Positive Control Technique is one form of the Yes-No Technique.See: Driscoll, Honts & Jones (1987); Gordon & Cochetti (1982); Howland(1981); Reali (1978).Post-Conviction Sex Offender Testing (PCSOT)Specialized application of polygraphy which aids in the management ofthe convicted sex offender who has been released into the community, thoughsometimes is employed as part of treatment of offenders who are incarcerated.There are four principal types of PCSOT examinations: instant offenseexamination, sexual history/disclosure examination, maintenance examinationand monitoring examination. See: Dutton (2000).Post Hoc(L: after this) Establishment of criteria or analyses after the conduct ofthe experiment is completed.PosttestFinal portion of a polygraph examination. The posttest could include adebriefing of an examinee who passed the examination, or an interview orinterrogation of an examinee who failed the examination. The posttest may ormay not be a part of any given polygraph technique, and plays no part in theformulation of the results in any polygraph technique.Pre-ejection period (PEP)Time between the Q wave of the electrocardiogram and the B wave of theimpedance cardiogram for the same pulse. It is the period between whenventricular contraction occurs and the semilunar valves open ejecting bloodinto the aorta. Shorter periods are thought to correlate very highly withsympathetic nervous system arousal. The sensors for the production of thePEP phenomenon are relatively noninvasive, and if future research validates itas a diagnostic measure, the PEP could be added as an alternate PDD channel.Preliminary Credibility Assessment Screening System (PCASS)Device developed by the Johns Hopkins Applied Physics Laboratory, inconjunction with the Lafayette Instrument company, at the request of the USGovernment in 2005. Its concept of operation is to be used by minimallytrained US troops as an initial screening tool in war zones to pare down thenumber of individuals who would undergo subsequent vetting by the polygraphand other tools. It has two sensors: electrodermal and photoplethysmograph.Test questions are typed into the template of the PDA platform, and the usertaps the screen to indicate the place of question onset. The PCASS is a onecharttest that runs about 12 minutes. At the completion of testing analgorithm analyzes the data to produce the screening decision. Five laboratorystudies have been conducted with the PCASS using realistic wartime scenariosor mock theft scenarios, with a combined accuracy of 80% when inconclusiveswere excluded, and about 23% inconclusives. The algorithm was devised tominimize false negatives. The PCASS was approved for use in the Departmentof Defense in 2007. See: Battelle Memorial Institute (2007); Senter, Waller &Krapohl (2009).Premature Ventricle Contraction (PVC)Term loosely applied to distortion in the cardiograph waveform resultingfrom an ectopic heartbeat. More precisely it is a ventricular contractionbetween two sinus cycles without a compensatory pause. Sometimes referredto as extrasystolic beat (esb) in the older literature.Pretest InterviewThe earliest portion of the PDD examination process during which theexaminee and examiner discuss the test, test procedure, examinee’s medicalhistory, and the details of the test issues. The pretest interview also serves toprepare the examinee for the testing. The length of the pretest interview rangesfrom 30 minutes to 2 hours or longer, depending on the complexity of the case,examiner-examinee interactions, and testing technique. All PDD techniquesuse pretest interviews.Primary TrackOne of four tracks in the Quadri-Track Zone Comparison Technique,which include the secondary, outside, and inside tracks. The primary trackcontains a relevant question, and a non-current exclusive probable-liecomparison question against which the relevant question is compared. See:Matte (1996).ProbabilityLikelihood of an occurrence, expressed as a number. By convention,probabilities are reported in scientific reports as numbers between 0.00 and1.00. Probabilities are most often reported in PDD studies to characterize thelikelihood of the experimental results occurring by chance.Probable-Lie Comparison Question (PLC)One of two major types of comparison questions. PLCs are questions towhich it is likely that the examinee is untruthful or unsure of his or heranswer. Their intended purpose is to create a competition of salience such thatthe anxious innocent examinees will expend more of their physiologicresponses on them than the relevant questions, but the guilty examinee willstill find the relevant questions more arousing than the PLCs. Most systems ofanalysis compare the physiological responses elicited by the PLC with thosefrom the relevant questions. A PLC is fundamentally different from a DLC(directed lie) in that the examinee believes he must pass the PLC question topass the examination, whereas the true purpose of the DLC is more apparentto the examinee. Two main types of PLCs are the exclusionary (Backster type)and the non-exclusionary (Reid type).Probation Polygraph TestingRegularly scheduled or aperiodic PDD testing of offenders on probationor parole, with the purpose of deterring repeat offenses. See maintenancepolygraph examination.Probing Peak of TensionSee Searching Peak of Tension.Programmed innocent/guiltyThose persons in a PDD experiment that play the role of either aninnocent examinee or guilty examinee. PDD examiners sometimes make themistake of referring to these examinees as programmed NDI (No DeceptionIndicated) or programmed DI (Deception Indicated). NDI and DI are PDDoutcomes and not the examinees’ experimental assignments.Pseudorelevant QuestionA test question so worded as to appear to be relevant to the examinee.Example: “Did you lie to any question on this test?” or “Do you intend toanswer truthfully each question on this test?”Psychogalvanic Reflex (PGR)Expression coined by Veraguth for what is now called the electrodermalresponse. See Veraguth (1906).PsychographA term from the 1930s for the polygraph that consisted of thepneumograph, sphygmograph, and a stimulus marker. Sometimes referred to as the Berkeley Psychograph, the Lee Polygraph, and the cardio-pneumopsychograph.Psychological SetIn psychology, set is defined as a temporary orientation or state ofpreparedness toward a particular stimulus or type of stimulus. Examples ofset include perceptual, motor, and neural sets. The expression psychologicalset was introduced in PDD by Cleve Backster, who initially attributed it to apsychological writer Floyd L. Ruch (Matte & Grove, 2001). Backster laterclaimed to have made up the expression himself (Senter, Weatherman,Krapohl, & Horvath (2010). Backster has made the concept central to his ZoneComparison Technique and has tethered the concept to the emotion fear.According to Backster’s PDD hypothesis, examinees are expected to attendmore to the category of question that presents the greater threat to theirinterests, either the relevant or comparison questions. Subjects who are lyingto the relevant issues consider these questions more threatening than theothers, which, in turn, draw more attention to the relevant questions, and morephysiological arousal. Similarly, innocent subjects find the probable-liecomparison questions more disconcerting, and the greater attention paid tothem generates the larger arousals. The expression psychological set, togetherwith its underlying assumptions, have long been questioned by scientists onboth sides of the polygraph debate, and there is not uniform agreement evenwithin the polygraph community that they are adequate. Nevertheless,psychological set is an oft-cited expression for the differential responsivityevoked by the Comparison Question Technique. Competing concepts include“Differential Salience” (Senter, Weatherman, Krapohl & Horvath, 2010) and“Relevant Issue Gravity” (Ginton, 2009.) See: Krapohl (2001); Matte & Grove(2001).Psychological Stress Evaluator (PSE)A voice stress device. Dektor Counterintelligence and Security and AllanBell Enterprises produced the PSE, first introduced in 1971. This device,which is no longer manufactured, is the original voice stress analyzer. See:Horvath (1978; 1979); Lynch & Henry (1979).PsychopathAn individual with a personality marked with superficial charm, habituallying, no regard for others, showing no remorse after hurting others, having noshame for outrageous and objectionable behavior, impulsivity, inability to formrelationships and take responsibility, failure to learn from punishment, lack ofempathy and conscience, and need for excitement. Also referred to asantisocial personality. While popular lore holds that the psychopath, with hisdiminished conscience, is able to defeat PDD testing, all research has foundthat the guilty psychopath is no different from guilty non-psychopaths in beingdetected by the polygraph. See: Barland & Raskin (1975); Raskin & Hare(1978); Patrick & Iaconno (1989).Psychophysiological detection of deception (PDD) Common scientific term to denote the use of the polygraph to diagnosedeception.Psychophysiological veracity (PV) examinationAn alternative expression proposed by James Matte to describe theprocess of making assessments of truthfulness or deception using a polygraph.Matte offered the term as an alternate to polygraph examination and forensicpsychophysiological detection of deception examination. The expression hasnot yet gained wide acceptance. See: Matte (1996).Pulse PressureThe arithmetic difference between the systolic blood pressure and thediastolic blood pressure.Pulse Transit Time (PTT)Period of time for the passage of a mechanical pulse wave between twopoints on the body. PTT is used as a measure of sympathetic nervous systemarousal and may have some usefulness as a PDD parameter.Pulse Wave VelocityPropagation speed of a pressure pulse through the vascular system.One of many cardiovascular measures being evaluated as a PDD diagnosticfeature.Punishment TheoryOne of several theories that attempt to explain PDD. It holds thatphysiologic arousal during deception is activated by the fear of theconsequences if detected. This theory fails to explain why polygraph testing stillfunctions well in the absence of fear.Pupillary ResponseChange in the diameter of the pupil of the eye in response to stimuli.Pupil size is regulated by the sphincter pupillae muscles in the iris, whichrespond to parasympathetic stimulation, and the dilator pupillae muscles,innervated by the sympathetic nervous system. Dilation can result fromsympathetic nervous system stimulation or the suppression of theparasympathetic nervous system. Pupil dilation has been investigated byseveral researchers as an index of stress, and continues to be a phenomenon ofinterest in PDD. See: Bradley & Janisse (1981); Webb, Honts, Kircher,Bernhardt & Cook (2009).Purposeful Non-Cooperation (PNC)An expression first reported by John Reid to denote a PDD outcome inwhich examinees had used physical countermeasures in an attempt to defeatthe polygraph examination. Reid did not consider PNC to be synonymous withthe practicing of deception, though he wrote that it was a fairly reliableindicator of the examinee’s motives to deceive.
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