In the realm of forensic science, particularly within polygraph examinations, the concept of salience—where an individual’s attention is significantly engaged by stimuli that pose the most considerable threat or relevance to their well-being—is pivotal. This principle underlies much of the current methodologies used in polygraph testing, guiding how questions are structured and interpreted.
Psychological Set and Salience
Originally attributed to Floyd & Rush (1948) and later discussed by Tichener in 1914, the psychological set is a foundational concept, although it curiously does not appear explicitly in their texts or other published psychological literature. This concept posits that a person’s fears, anxieties, and apprehensions are directed towards the situation posing the greatest immediate threat to their self-preservation. This selective attention helps tune out lesser threats, focusing the individual’s senses on detecting and reacting to significant dangers.
The Theoretical Underpinnings
Several theories have attempted to explain how and why certain stimuli become salient during a polygraph test:
- Conditioned Response Theory: Rooted in the works of Pavlov (1927), this theory suggests that autonomic responses can be conditioned by emotionally charged experiences. For instance, the mere mention of a situation linked to a transgression could evoke a conditioned response if previously associated with stress or fear.
- Orienting Theory: Developed by Sokolov (1963), this theory details how individuals orient themselves towards novel or significant stimuli. This is a biological mechanism intended to facilitate an adaptive response, helping to distinguish between what is routine and what may require a more focused response.
- Dichotomization Theory: Proposed by Ben-Shakhar (1977), this theory posits that stimuli can be categorized as either threatening or neutral. The nature of the response—defensive or orienting—depends on this categorization, with salient stimuli evoking a more sustained attention and slower habituation.
- Conflict Theory and Arousal Theory: These theories delve into the internal conflicts an individual experiences and how these conflicts, alongside the personal significance of a stimulus, can lead to varied physiological responses. This variability is crucial for interpreting polygraph results, especially in distinguishing between truthful and deceptive responses.
Salience in Non-Naïve Subjects
In practical polygraph testing, especially with subjects who have undergone such testing before (“non-naïve subjects”), the relevance of questions can trigger significant physiological responses due to the fear of false accusations or the stress of recalling traumatic events. Such responses may be potentiated by past experiences with the legal system, making certain questions more salient than others.
Challenges and Considerations
Despite the foundational role of these theories in enhancing our understanding of physiological responses in polygraph tests, they also bring to light the inherent complexities of measuring and interpreting these responses. The use of idiosyncratic jargon within the polygraph community, referred to as “poly-babble,” further complicates the credibility and acceptance of polygraphy in broader scientific and forensic contexts.
The polygraph does not measure lies directly; instead, it measures physiological responses to carefully designed questions where the salience of each question influences the reaction. These responses are then scored, and using normative data, examiners calculate the probability of deception.
Conclusion
The intersection of psychological theory with polygraph testing offers valuable insights into human behavior under scrutiny. By understanding the underlying mechanisms of attention, conditioning, and emotional response, professionals can refine polygraph techniques, enhancing both their reliability and validity. As the field continues to evolve, ongoing research and adherence to scientific principles will be vital in mitigating challenges and advancing the credibility of polygraph testing within the forensic sciences.