Terms Relating to Lie Detectors Explained – Letter G
Galvanic Skin Response (GSR)
A superseded term for the electrodermal response measured
exosomatically by the change in the electrical resistance of skin. GSR is
sometimes erroneously called Galvanic Skin Resistance or Galvanic Skin
Reflex. The modern term is electrodermal response (EDR).
Polygraph component responsible for producing the graphic recording of
A cluster of nerve cell bodies. (pl. ganglia).
General State Countermeasures
Attempts to defeat the polygraph examination by influencing tonic
physiological activity, or altering phasic lability. Typical approaches include
the use of drugs, meditation, biofeedback, and fatigue. The goal of state
countermeasures is to diminish the body’s responses to all polygraph
questions. State countermeasures may affect testing techniques that rely on
the presence or absence of responses to diagnose deception, such as the
Concealed Information Test or Peak of Tension tests. Because comparison
question tests use differential responsivity to different types of questions, state
countermeasures are more likely to result in inconclusive findings than errors.
See: Honts & Amato (2002).
Extent to which a set of research results can translate to other research
paradigms or to the real world.
General Nervous Tension (GNT)
Expression used in the practice of PDD to characterize recorded
physiological patterns that suggest the examinee’s basal level of arousal is
high. This arousal is not indicative of deception in itself. GNT is sometimes
indicated by very fast heart rates, unusually labile electrodermal activity, and
uneven respiration cycles. PDD examiners try to bring examinee’s arousal
state to a median level to optimize the interpretability of the test charts.
General Question Technique
Alternate expression for the Keeler Relevant/Irrelevant Technique.
Evaluation of the polygraph recordings as a whole, as opposed to making
systematic comparisons among questions. Global evaluation can also
represent the use of extrapolygraphic information such as subject behavior and
case facts when rendering a polygraph decision, an approach championed by
Reid and Arther. When information beyond the physiological tracings are
considered to produce the final outcome, it is also called the clinical approach.
Term used by Cleve Backster to describe a 20-to-35 seconds block of
polygraph chart initiated by an exclusionary comparison question which has a
unique psychological focusing appeal to innocent (truthful) examinees. See:
Computer polygraph manufactured in Russia.
Reality. In the PDD context it is the veridical state of truthfulness or
deception against which polygraph outcomes are compared in validity studies.
Ground truth is an elusive feature in field studies because it is difficult to
independently verify guilt or innocence in many cases. In laboratory studies, it
is delineated into programmed guilty and programmed innocent groups.
Invented expression by a polygraph manufacturer to represent a
measure of skin conductance. An adaptation of GSR, substituting the letter
“R” with “G,” the engineering shorthand for conductance. However, GSR
stands for Galvanic Skin Response, not Resistance. The phenomenon called
GSG is more correctly denoted as skin conductance (SC).
Guilt Complex Reactor
Hypothetical personality trait that causes innocent examinees to
physiologically respond to any question that they consider accusatory. Guilt
complex questions have been used in many of the contemporary formats at one
time or another in an attempt to identify those examinees who would produce a
false positive outcome because of this tendency. No empirical support exists for
the existence of guilt complex examinees nor for the benefit of using a test
question aimed at identifying them.
Guilt Complex Test
A PDD test format in which an examinee is tested on a fabricated crime.
The guilt complex text has several hypothetical purposes, primarily in avoiding
false positive outcomes. The guilt complex test was taught in the earliest years
of the Reid and Keeler schools. See: Abrams (1977).
Guilty Knowledge Test (GKT)
A test published by Dr. David Lykken, and is based on a concealed
information paradigm. While similar tests are described in the literature as
early as 1904 (Wertheimer & Klein), and Hugo Munsterberg outlines a
comparable approach in his 1908 book On the Witness Stand, Lykken
formalized the procedures, and advocated its use in place of the CQT. Recent
writers have renamed this method the Concealed Information Test (CIT), arguing
it is a more correct name because knowledge can’t be guilty of anything. See:
Lykken (1959); Verschuere, Ben-Shakhar & Meijer (2011).