Episode 5: Demystifying Polygraphs

NorthPoint Counseling Perspective

In this episode, counselor and author John Sternfels discusses Polygraphs, also known as lie detectors. Polygraphs are instruments used to measure physiological responses associated with truthfulness or deception. The primary purpose of a polygraph test is to assess whether a person is being truthful or deceptive in their responses to a set of questions.
Here are some key components and principles associated with polygraph examinations:

1. Physiological Measurements:
   • Heart Rate: Polygraphs measure changes in heart rate using an electrocardiogram (ECG) to monitor the heartbeat.
   • Respiration Rate: A pneumograph tracks the rate and depth of breathing.
   • Galvanic Skin Response (GSR): Electrodermal activity is measured to assess changes in skin conductance, which can indicate emotional arousal.
2. Test Procedure:
   • During a polygraph examination, a person is asked a series of questions while the polygraph records physiological responses.
   • The test typically involves a pre-test interview to establish baseline readings and discuss the questions that will be asked.
   • Relevant, irrelevant, and control questions are used to assess reactions. Relevant questions relate to the issue being investigated, while irrelevant questions are unrelated.
3. Scoring and Interpretation:
   • Polygraph examiners analyze the physiological data to identify significant changes associated with deceptive or truthful responses.
   • The examiner interprets the results based on patterns of physiological responses.
   • It's important to note that the accuracy and reliability of polygraph results have been a subject of debate among experts.

John Sternfels, LPC, NCC, CSAT, CMAT, CCPS, C-SASI
Owner/Clinical Director of NorthPoint Professional Counseling
Counselor and Author
Books Available:
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