Terms Relating to Lie Detectors Explained – Letter B
- Backster, Cleve
- Originator of the Trizone Comparison Test, more often referred to as the Zone Comparison Technique. Backster also introduced to the polygraph profession the concepts of “psychological set,” zones, spots, superdampening, anticlimax dampening, symptomatic (outside issue) questions, exclusionary comparison questions, and 7-position scoring for use in chart analysis. Backster heads a private training facility in San Diego, California, and has provided training for thousands of examiners since the late 1940s. He also began the CIA polygraph program in 1949.
- Barland Chart Overlay
- A transparent chart overlay developed by Dr. Gordon H. Barland in 1982 for the interpretation of the curvilinear polygraph tracings from analog polygraphs. See: Matte (1996)
- Base Rate
- Incidence of something in a population, often expressed as a proportion or percentage. Base rates can affect on the overall accuracy of a technique. When base rates are relatively high, detection is much easier than in low base rate conditions. As an example, in medicine there is a much lower false positive rate with a diagnostic technique when the base rate of incidence is 50% than 0.1%. Similarly, in PDD it is much easier to find the one guilty individual in a tested population of two (50% base rate) than the 1 guilty person among 1,000 suspects (0.1% base rate). Statements of PDD validity are incomplete unless they also identify the characteristics of the tested population. The base rate problem is not unique to PDD, but is also found in all other diagnostic tests. See: Gastwirth (1987); Kircher & Raskin (1987); Murphy (1987).
- Baseline Arousal
- Term used in PDD to characterize a marked upward shift in the entire respiration tracing. Baseline arousals do not always occur during deception; however, when they are observed they are reliable indicators of stress. Some baseline arousals are relatively short-lived, lasting only a few respiration cycles, while others may continue much longer.
- Behavior Countermeasures
- A class of countermeasures by which an examinee attempts to sway the examiner or influence the conduct of the session. The intent is to influence the decision maker or restrict the ability of the decision maker to conduct a valid examination. By definition, behavioral countermeasures have no influence on the physiologic tracings. The effect is sociopsychological in nature (interpersonal dynamics) rather than psychophysiological. See: Krapohl (1996).
- Behavioral Analysis
- Method for developing extrapolygraphic information that may be useful in the diagnosis of truth or deception. The behaviors of interest may be naturally occurring within the context of the polygraph examination, or are the result of questions posed by polygraph examiners during the interview phase of the session. The inclusion of behavioral analysis in the polygraph decision process is controversial.
- Benussi, Vittorio
- One of the first researchers to examine respiration tracings for detecting deceptions. Though Italian, Benussi did most of his work in Austria at the University of Graz. See: Benussi (1914).
- Berkeley Psychograph (Or Lee Polygraph)
- Two-channel polygraph with event marker assembled by C.D. Lee of Berkeley and used in criminal testing. It included a stimulation marker, pneumograph and cardiograph, and recorded these channels simultaneously on moving graph paper. It was designed to be as portable as a suitcase. Lee sold his Berkeley psychographs from the 1930s into the 1950s, and they were delivered complete with pens, sensors, paper, and instructions.
- Beta Blocker
- Adrenergic blocking agent affecting responsivity of the cardiovascular system and used to treat specific cardiovascular conditions such as high blood pressure and arrhythmias. Because they appear to dampen cardiovascular phasic responsiveness, beta blockers are of concern to PDD examiners because of their potential as a pharmacological countermeasure. Testing of examinees who take beta blockers is routine practice, as some cardiovascular responsiveness usually persists even with the medication.
- Bias
- In research it is a source of systematic error that can influence the outcome of the experiment. Bias can be introduced into research by factors such as, among others, nonrandom sampling, faulty subject instructions, or expectations of the researcher or the participants. In a PDD study looking at the validity of blind scoring, for example, a researcher using only cases which were verified by the original examiner are likely biasing the study, since cases that the original examiner made the wrong diagnosis could be systematically excluded from the research sample. Researchers attempt to control bias through experimental design.
- Biofeedback
- Use of a device to measure and convey physiological information back to a subject. It has been proposed as a potential countermeasure approach. Biofeedback is not a countermeasure in itself, but rather a means of teaching a subject to influence autonomic responsivity. Research indicates that biofeedback is better suited for self-regulation of tonic activity than phasic activity. As a result it may be useful to dampen or increase responsiveness in general during a test, but less so within a test to a given question. It has been suggested that this has implications for test formats such as Relevant/Irrelevant and Peak of Tension, but probably not for tests using comparison questions such as the Reid and Zone formats. Biofeedback can also be used to enhance responsiveness in subjects during testing. It has been hypothesized that the immediate biofeedback serves to elicit greater responding to questions when deception is practiced by the examinee. There is some empirical evidence of this effect, but it has not been unequivocally established.
- Biphasic Response
- Physiological reaction that has two phasic responses, in opposite directions. Biphasic responses of a diagnostic nature in PDD are found in the skin potential and heart rate recordings.
- Bizone
- Incorrect term applied to a Zone Comparison Test containing two relevant questions. See zone.
- Black Zone
- In the Backster framework, it is a 20-to-35 seconds block of polygraph chart time initiated by a symptomatic question having a unique psychological focusing appeal to the examinee who is fearful that the examiner may ask an unreviewed question dealing with an outside issue. Because subsequent research has not been supportive of the symptomatic question, the value of the black zone has been called into question. See: Backster (2001); Krapohl & Ryan (2001).
- 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. Studies employ various degrees of “blindness.” It is a popular research approach to gauge interrater reliability. Assessments of the accuracy of PDD test evaluation techniques also use blind chart analysis.
- Blind Stimulation Test
- Stimulation test in which the examiner does not know the critical item at the beginning of the test. See stimulation test.
- Blocking
- Pattern sometimes seen in the pneumograph tracing in which the examinee discontinues respiration at or near the inspiratory peak. Blocking can be differentiated from a typical apnea in that the latter most often occurs near the end of the expiratory segment of the respiration cycle. Blocking is many times a deliberate attempt on the part of the examinee to influence the physiological activity recorded by the polygraph.
- Blood Pressure
- The force blood exerts against the walls of the blood vessels, usually measured in millimeters of mercury, is called blood pressure. PDD examiners evaluate only relative blood volume changes, as current polygraphs are not capable of providing absolute blood pressure measurements. Also see systolic blood pressure, diastolic blood pressure, mean blood pressure, and pulse pressure.
- Blood Volume (Bv)
- Quantity of blood in an organ or limb, usually recorded as relative increases and decreases in the circumference of the affected area or size of blood vessels. Localized changes in blood volume are mediated by chemical and neural mechanisms, such as the shunting of blood to the major muscle groups during sympathetic nervous system activations.
- Bogus Pipeline (Bpl)
- Sociopsychological effect whereby a subject will make more candid and sometimes more incriminating revelations about himself when he believes a device attached to him will reveal his true knowledge or attitudes. The BPL was first reported by Jones and Sigall, who convinced subjects that the electromyograph used in their study could measure internal feelings, and found that their subjects were more willing to disclose socially-undesirable attitudes. Some critics of polygraphy contend that PDD is merely an elaborate BPL that has only the power to elicit confessions but not assess truthfulness or deception. See: Jones & Sigall (1971).
- Bootstrapping
- A statistical technique. Bootstrapping involves pooling the data from two samples and drawing samples repeatedly from the pool, with replacement, to create a single distribution. The number of samplings taken to create the distribution is typically in the thousands. Then the two original samples are compared using this grand distribution as an estimate of the true population to determine whether they are significantly different from one another. Bootstrapping has been applied both to PDD and brain wave approaches. See: Farwell & Donchin (1988); Honts & Devitt (1992); MacLaren & Taukulis (2000).
- Brachial Artery
- Major blood vessel located in upper arm. Occlusion blood pressure sensors are frequently placed there, and it is the preferred placement site for the blood pressure cuff in PDD.
- Bradycardia
- Heart rate of under 60 beats per minute. Brachycardia is common among athletes and those with hypothyroidism. Slow heart rate can also indicate the influence of medications.
- Bradypnea
- Very slow and abnormal respiration, longer cycle time. The term does not distinguish between autonomic and deliberate respiration slowing.
- Brain Stem
- Includes the adult brain structures, i.e., midbrain, pons and medulla (mesencephalon) region structures including the thalamus, third ventricle and hypothalamus. These structures are essential for the automatic control of respiration and cardiovascular systems.
- Breakdown (Or Breakout) Test
- PDD test in which a single issue is addressed, and is always given after a multiple-issue test has indicated that the examinee has consistently responded to that issue. It is generally conducted in one of the validated test formats, such as Zone Comparison Tests or the Modified General Question Test. Question coverage can be single- or multi-faceted. The rationale for this two- stage approach to PDD testing is that, while multiple-issue screening examinations are very useful in identifying which among several issues the examinee is concerned with, they lack the power of these single-issue formats in making correct determinations of deception or truthfulness. This approach is used in many polygraph screening programs to maximize both utility and accuracy of PDD in preemployment and other applications.
- Brilograf
- Device for measuring changes in skin resistance. Built in the 1940s by Jacques Bril, a criminologist, Brilograf was based on similar work he had done with Rev. Walter Summers on the “Pathometer.” Not generally used and is only of historical note.
- Burtt, Harold E.
- Researcher into deception tests using respiration. Burtt devised a formula to evaluate respiratory responses for detecting deception based largely on the ratio of the time to inhale to that of the exhalation. See: Burtt (1918;1921).
