Up- and down-regulating facial disgust: affective, vagal, sympathetic, and respiratory consequences

Relative to watching in a natural manner, people asked to suppress or exaggerate their facial response to a negative emotional stimulus experience greater activation of the sympathetic nervous system but report a similar subjective emotional experience. The present research extends prior research on response modulation in two important ways. First, discrete indicators of cardiac vagal and sympathetic control (respiratory sinus arrhythmia (RSA) and pre-ejection period (PEP), respectively) were included as dependent measures along with interbeat interval (IBI) and skin conductance (EDR). Second, to help generalize results across response-focused modulation techniques, participants suppressed, exaggerated, or exerted no control over their responses while watching a disgust-eliciting film (for control purposes, a fourth group was asked to watch a neutral film naturally). Response modulation was associated with significantly decreased PEP (increased cardiac sympathetic control) relative to those in the natural-watch conditions. All participants evidenced increased EDR while watching the disgusting clip, but facial modulation did not produce EDR reactivity beyond that of watching the disgusting film naturally. Exaggerators experienced decreased IBI during modulation (perhaps due to increased muscle contraction) whereas all other groups showed increased IBI (i.e., the orienting response). Neither emotional experience nor facial modulation reliably impacted RSA, respiration rate, or inspiratory depth.