Polygraph Glossary Physiology

Salience

Definition

The psychological significance or personal relevance of a stimulus (question) to the examinee, which drives the magnitude of physiological response. In polygraph theory, relevant questions are more salient to deceptive examinees (producing larger responses) while comparison questions are more salient to truthful examinees. The modern scientific term replacing the older concept of "psychological set."

What Is Salience?

Salience is a physiological concept in polygraph science. The psychological significance or personal relevance of a stimulus (question) to the examinee, which drives the magnitude of physiological response. In polygraph theory, relevant questions are more salient to deceptive examinees (producing larger responses) while comparison questions are more salient to truthful examinees. The modern scientific term replacing the older concept of "psychological set."

Physiological Basis and Measurement

Understanding the physiological mechanisms underlying polygraph testing is essential for examiners, researchers, and anyone evaluating polygraph evidence. The polygraph measures outputs of the autonomic nervous system (ANS) — involuntary physiological processes that respond to stress, threat perception, and cognitive load associated with deception.

When a deceptive examinee encounters a threatening relevant question, the brain's threat detection system triggers the fight-or-flight response, producing measurable changes in electrodermal activity, cardiovascular function, respiration, and other autonomic outputs. These involuntary responses form the data that examiners and scoring algorithms analyse.

Implications for Polygraph Testing

This physiological concept has direct implications for polygraph examination practice, including suitability screening (assessing whether the examinee's physiological condition supports valid testing), artifact identification (distinguishing genuine psychophysiological responses from noise), and the interpretation of scoring results.

Related Terms

Understanding Salience in context requires familiarity with several related polygraph concepts:

Key Takeaways

Salience is an important concept within the field of Psychophysiological Detection of Deception. Whether you are a polygraph examiner, student at an APA-accredited training program, legal professional evaluating polygraph evidence, or a private individual preparing for a lie detector test, understanding this term and its relationship to other polygraph concepts will help you navigate the field with greater confidence and knowledge.

The science of polygraph testing has evolved significantly over more than 100 years, from the early work of William Moulton Marston and Leonarde Keeler to today's digital instruments and validated scoring algorithms. Every term in this glossary represents a piece of that scientific and professional heritage. For a comprehensive overview, visit the Polygraph Examiner Hub or use our examiner selection guide to find a professional examiner near you.

Cross-references

More physiology terms in this glossary

homeostasis Homeostasis describes the maintenance of internal physiological stability within a prescribed range. While organisms ... noradrenaline Noradrenaline is the British term for norepinephrine — the primary neurotransmitter released by most adrenergic (symp... dendrite A dendrite is a branching process of a neuron specialised to receive incoming signals from other neurons. Dendrites f... vagus nerve The vagus nerve is the tenth cranial nerve providing parasympathetic innervation to the heart and other visceral orga... error-related negativity Error-related negativity (ERN) is a brain wave time-locked to response selection that corresponds with incorrect choi... skin potential level Skin potential level (SPL) is the tonic (baseline) electropotential of the skin.

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