Terms Relating to Lie Detectors Explained – Letter T
T Test
A statistical test frequently used with small samples (when the number
of observations is less than 30) to determine whether the mean of one sample
is significantly different from that of other.
Takei
Japanese manufacturer of analog polygraphs.
Tachycardia
Abnormally rapid heart beat, greater than 100 beats per minute.
Tachycardia can result from poisoning, medications, certain illnesses, and
during states of anxiety or excitement. A rapid heart beat is normal for the
very young or during the physical exercise of normal adults. While not a
diagnostic feature in itself, PDD examiners pay attention to heart rate during
evaluation of the polygraphs as it may signal pharmaceutical countermeasures
or atypical levels of stress.
Tachypnea
Rapid breathing, usually shallow.
Target Intensity
A variable considered by examiners in the rating and selecting of test
issues (targets), as well as in the sequence of test questions in multiple-issue
testing. It is anticipated that the guilty examinee’s greatest concern will be
directed toward questions dealing with the most serious test issues—those with
the greatest consequences to the examinee—with less or no attention being
allocated toward relevant questions where the consequences of discovery of
guilt are relatively less costly to the examinee, such as minor criminal acts.
Taxonomy
A system of categorization based on specific criteria. A typology.
Taxonomies are used to organize concepts or phenomena into meaningful
groups. There are currently PDD taxonomies for techniques, scoring systems,
and countermeasures.
Technique
All practices taking place in a polygraph examination, including pretest
procedures, question formulation, format, number of tests, test sequencing,
and scoring and decision rules.
Test
In PDD, the test is used to differentiate a single running of a question
series (sometimes also called a chart) during physiological recording from the
examination, which is considered to be the totality of the PDD process. It can
also refer to specialized procedures within techniques, such as the Yes Test
and stimulation test. Test has been erroneously used to refer to polygraph
techniques, such as the Zone Comparison Test, or Modified General Question
Test.
Test Aata Analysis (TDA)
Newer expression for polygraph chart interpretation, a change prompted
by digital polygraphs where physiological data are displayed on computer
screens rather than paper strip charts.
Test for Espionage and Sabotage (TES).
Multiple-issue testing format employed by some U.S. Government
agencies for screening purposes. The TES uses a repeated series of relevant
and directed-lie comparison questions, and the conventional 7-position scoring
system. See: Reed (1994); Research Staff (1995;1998). Also see Directed Lie
Screening Test
Thenar Eminence
Prominence on the palm at the base of the thumb. One of the optimal
recording sites for electrodermal activity, and a preferred location in
psychophysiological research. See: Handler (2010).
Thermal Imaging
A technique that uses a camera to record the emission of radiant energy
from the body. The basis for the technology is that any object with a
temperature greater than 0 degrees Kelvin radiates energy in the infrared (IR)
range. Although IR energy cannot be seen by the human eye, thermal cameras
are equipped to record this form of energy. Changes in thermal patterns on the
face have been shown to be associated with physiological arousal, and
preliminary evidence suggests that thermal imaging can discriminate between
truthtellers and deceivers at better than chance using a probable-lie
comparison question technique. See: Pavlidis, Eberhardt & Levine (2002);
Pollina (2006); Pollina & Ryan (2003).
Thoraco-Lumbar Division of Autonomic Nervous System
An anatomical division of the autonomic nervous system (ANS) that
represents the sites of outflow from the sympathetic division of the ANS (i.e.,
nerves from the thoracic and abdominal parts of the body). It is the location of
the 21-22 pairs of ganglia that constitute the sympathetic chain.
Thumb Transducer
Cardiovascular sensor consisting of an external ring and internal
bladder, into which is placed the thumb. The bladder is inflated to a small
pressure, and the sensor detects changes in the relative blood volume of the
thumb. Because of the weakness of the signal, the thumb transducer requires
an electronically enhanced cardiograph channel.
Time Bar
One method of restricting the coverage of the comparison question so
that it will not include the time in which the incident under investigation took
place. Time bars generally predate the crime. A typical time bar for the
comparison question might be phrased “Before the age of X, did you ever…” or
“Prior to 1998, did you ever …” There is a school of thought that examinees
may confuse the relevant questions with the comparison questions unless
these two types of questions are designed to avoid any degree of overlap.
Research has not supported this hypothesis, however. See: Amsel (1999);
Podlesny & Raskin (1978); Horvath (1988); Horvath & Palmatier (2008). Also
see exclusive (exclusionary) comparison question
TiPi
A voice stress device. Nemesysco produces TiPi, first introduced in
- Prior versions of the product were Vericator, produced by Integritek
Systems, and TrusterPro, produced by Trustech. Training can be obtained but
is not required. Multiple testing formats are possible, including PDD formats.
See voice stress analysis.
Tone
A term used to describe the reaction free autonomic state.
Tonic Change
Shifting of tonic level to a new baseline, typically at a relatively slow rate
compared to phasic responses.
Tonic Level
Baseline level. This terminology in PDD is frequently used to delineate
basal waveform levels from short-term responses induced by stimuli. Tonic
levels change slowly compared to phasic activity.
Tonic Response
Shifting of tonic level, typically in response to changing conditions. For
example, the adjustment of electrodermal tonic levels due to temperature
changes, reduction of pulse rate between standing and reclining, and faster
breathing that accompanies an increase in walking speed. Tonic responses
take several seconds or minutes to occur, unlike phasic responses which tend
to be very rapid. Some examiners consider changes in tonic activity as
diagnostic information in Peak of Tension tests, where a change in the trend of
tonic activity can signal that the critical item in the series has passed.
Research evidence is lacking despite frequent anecdotal reports.
Total Chart Minutes Concept (TCMC)
A concept offered to consider possible variation in the rate of habituation
for the individual physiological parameters recorded in PDD. Backster
developed a habituation curve for each of the parameters for the amount of
time these activities were recorded during testing, and published his report in
- It has not received much attention among researchers, and is not
currently taught in the field. See: Backster (1963b; 2001b); Krapohl (2001).
Tracing Average
Section of the physiological tracing used as a comparative baseline, and
in which there are no indications of physiologic arousal. Also referred to as the
baseline level.
Tracing Distortion
Contamination of a physiologic tracing, typically by movements of an
examinee. Also referred to as artifact.
Track
Term relating to pairs of polygraph test questions that are used for
evaluative purposes, and a concept central to the Quadri-Track Zone
Comparison. See: Matte (1996)
Transducer
Device for transforming energy of one type into energy of another type.
In PDD a transducer is most often used in the context of converting pressure
changes into electrical signals.
Traube-Hering-Mayer (THM) wave
Rhythmic low-frequency fluctuation in heart rate (~0.1 hz) linked to a
blood pressure feedback loops and involving the carotid baroreceptors. The
THM wave is a contributing component to the variability expressed in the
respiratory sinus arrhythmia. See vagal tone.
Tremograph
Instrument for recording tremors and an early deception detection
approach. In the 1930s Luria proposed that trembling could be used as index
of emotional arousal, leading to possibilities in detecting lying. His hypothesis
was based on his conflict theory (i.e., incompatible emotions affect bodily
responses). See conflict theory.
Tri-Zone
An incorrect term sometimes used for a ZCT with three spots, or relevant
questions. See Zone Comparison Technique.
Tri-Zone Indication-Remedy Table
A “first aid” technique of the Backster methodology to immediately detect
and remedy any Zone Comparison technique defect or weakness.
True Blue Control Test
Stimulation test somewhat similar to the known numbers test, except
that the examinee is also directed to lie to an item that is partially both true
and false. See Stimulation Test.
True Negative
Correct decision that the variable of interest is not present (i.e., an
accurate PDD outcome of innocence).
True Positive
Correct decision that the variable of interest is present (i.e., an accurate
PDD outcome of guilt).
Two-Stage Rules
Two-Stage Rules function with the sequential use of the Grand Total
Rule followed by Spot-Score Rules. Subtotal scores are not permitted to
supersede the grand total score. Two-Stage Rules have been shown to reduce
the occurrence of inconclusive results and with no decrement to the proportion
of correct decisions. See Senter Rules.
Type A Test
See Known Solution Peak of Tension test.
Type B Test
See Searching Peak of Tension test.
Type I Error
The probability of rejecting a true null hypothesis. Alternatively, it is the
probability of incorrectly accepting the alternate hypothesis. Denoted as α and
in PDD consider a false-positive test result.
Type II Error
The probability of not rejecting a false null hypothesis, and denoted as β
in PDD consider a false-negative test result.
