Two coupled quantities decay after a stressor: I — subjective emotional intensity (what you consciously feel), driven by top-down prefrontal cortex (PFC) control; and P — physiological arousal (heart rate, sweat, muscle tension), driven more by the body itself. Both follow simple exponential relaxation:
dI/dt = -k_I(strategy, effort) · I
dP/dt = -k_P(strategy, effort) · P
- Reappraisal — reinterpreting the trigger recruits the PFC strongly (visualised as the blue signal streaming down to the amygdala): both I and P fall together and fast. k_I and k_P both scale directly with effort.
- Suppression — hiding the outward expression lowers I quickly, but does little to the underlying physiology: k_P stays low and mostly effort-independent, so P lingers — the "hidden arousal" gap is the classic finding that suppression looks calm but the body stays activated.
- Mindfulness — non-judgemental attention to the body (amber signal rising from below) brings P down first and I follows it, so the two stay close together with no hidden gap, at the cost of a slower start.
- Trigger stressor — injects a jolt of intensity and arousal (scaled by "Trigger intensity") into the amygdala, then regulation begins acting immediately at the current "Regulation effort".
This mirrors PFC→amygdala inhibitory circuitry and the well-replicated finding (Gross, 1998; Gross & Levenson, 1997) that expressive suppression reduces felt emotion far less than it reduces physiological reactivity, while cognitive reappraisal and mindfulness reduce both.