1 THE AUTONOMIC PHYSIOLOGY OF TERROR MANAGEMENT ...

Porges’ with his Polyvagal Theory, the physiology of which was described
earlier, is perhaps most influential in his theorizing about the psychology of vagal tone.
He posits that vagal tone indexes attention regulation as well as emotional regulation,
because vagal tone indexes metabolic demand. Attention processes and “the primary
emotions are often related to survival” and survival is tied to the ability to mobilize and
thus regulate the heart (p.314, 1995). Thus, “vagal tone is actively withdrawn in response
to external demands, including metabolically demanding states such as exercise, stress,
attention, and information processing” (p.306, 1995).
Other perspectives similarly interpret vagal tone as having to do with emotion and
attention regulation, but tend to distinguish more between tonic and phasic changes in
vagal tone. The general consensus is that high tonic levels of vagal tone index attention
and emotion inhibition resources, and thus the ability to flexibly regulate attention and
emotion in ways appropriate to the situation (e.g., Friedman and Thayer, 1998; Thayer &
Lane, 2000; Beauchaine, 2001). Consequently, reduced flexibility indexed by low tonic
vagal tone manifests itself in psychological difficulties such as “poor attentional control”,
(Thayer & Lane, 2000, p.206), “poor affective information processing” (Thayer & Lane,
2000, p.213), “negative emotional traits” (Beauchaine, 2001, p.199).
There is less agreement upon the meaning of phasic changes in vagal tone. Porges
and Beauchaine (2001) generally posit that large phasic decreases in vagal tone can be
thought to indicate “emotional lability of a fight or flight nature” (Beauchaine, 2001,
p.198-199) and “negative emotional states”, as compared to more “moderate vagal
withdrawal” (Beuchaine, 2001, p.199). However, Gottman and colleagues (e.g., Gottman,
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