A startle-probe methodology for investigating the effects of active avoidance on negative emotional reactivity

This study introduces a new methodology for investigating the impact of active avoidance and behavioral control on defensive emotional reactivity using the startle reflex. A between-groups yoked design was devised that permitted manipulation of participants' perception of control over an aversive event (loud noise) while precisely controlling motor activity and noxious stimulation. Startle responses to tactile (airpuff) probes were compared during threat/performance trials and neutral trials. Results conclusively demonstrated cross-modal startle potentiation in the context of a continuous motor performance task. Also, consistent with prior research, heart rate increased with perceived control. However, behavioral control per se did not appear to mitigate defensive emotion as indexed by startle potentiation. These findings indicate that other parameters may mediate the efficacy of active coping in addition to control, and that the startle probe paradigm can provide a valuable tool for investigating these parameters in future research.