What physiological measures does a polygraph typically record?

What physiological measures does a polygraph typically record?

• A. Blood pressure, electrodermal activity, and respiratory changes
• B. Brain activity and heart rate
• C. Blood glucose and muscle tension
• D. Temperature and reflexes

Answer: (A)

The main concept here is understanding what physiological signals a polygraph uses to gauge arousal during questioning. A polygraph typically tracks autonomic nervous system responses, primarily through three channels: electrodermal activity (skin conductance), respiratory changes (breathing rate and depth), and cardiovascular changes (such as heart rate and blood pressure). These sensors are placed to monitor how your body responds to questions, with the idea that heightened arousal can accompany stress or anxiety often associated with deception. So the combination of blood pressure or pulse changes, skin conductance, and breathing patterns is what a polygraph records. Brain activity isn’t measured by a standard polygraph, which is why options that include brain signals aren’t correct. Similarly, blood glucose, general muscle tension, or temperature and reflexes aren’t the typical trio used in polygraph testing, so they don’t fit the standard recording setup.

The main concept here is understanding what physiological signals a polygraph uses to gauge arousal during questioning. A polygraph typically tracks autonomic nervous system responses, primarily through three channels: electrodermal activity (skin conductance), respiratory changes (breathing rate and depth), and cardiovascular changes (such as heart rate and blood pressure). These sensors are placed to monitor how your body responds to questions, with the idea that heightened arousal can accompany stress or anxiety often associated with deception. So the combination of blood pressure or pulse changes, skin conductance, and breathing patterns is what a polygraph records.

Brain activity isn’t measured by a standard polygraph, which is why options that include brain signals aren’t correct. Similarly, blood glucose, general muscle tension, or temperature and reflexes aren’t the typical trio used in polygraph testing, so they don’t fit the standard recording setup.