allostasis

What Is Allostasis?

Allostasis is a modern physiological concept describing how the brain and body maintain stability through continuous change. Unlike the older concept of homeostasis — which implied fixed set points that the body seeks to restore — allostasis recognises that regulatory systems have no single fixed set point. Instead, the body continuously adjusts its parameters through integrated brain-body responses geared toward viability and survival.

Why Allostasis Replaces Homeostasis

The traditional concept of homeostasis, developed by Walter Cannon, suggested the body maintains internal constancy at predetermined levels. Allostasis, as applied to polygraph science, provides a more accurate framework because it acknowledges that physiological baselines naturally shift in response to changing conditions — including the psychological demands of a polygraph examination.

Relevance to Polygraph Testing

Allostasis helps explain several phenomena observed during polygraph testing. First, examinees' baseline levels naturally shift throughout the examination as the body continuously adapts to the testing environment — this is normal allostatic regulation, not necessarily an indication of countermeasure activity. Second, the differential responding between question types that Comparison Question Techniques exploit persists even as overall arousal levels change, because allostatic regulation maintains the relative response patterns even as absolute levels shift.

The concept is central to the autonomic regulation framework used by modern polygraph practitioners. Organisms are always in a state of allostasis — even during states of arousal — except during illness or disease.

References

See: Handler, Rovner & Nelson (2008).