Heart Rate, Contingent Negative Variation, and Evoked Potentials during Anticipation of Affective Stimulation

Thirteen subjects low in fear of mutilation and 11 subjects high in this fear were exposed to repeated presentations of a 6‐sec tone followed by slides depicting a mutilated body or a 6‐sec tone of a different frequency paired with a slide of a neutral scene. For both groups, the N140 component of the evoked potential was larger following the signal for gruesome slides. Slow EEG activity displayed two negative waves. Notably, the late CNV wave was present even though a motor response was not required at the end of the foreperiod. Overall, high‐fear subjects' early waves tended to be larger preceding neutral scenes than gruesome slides, whereas low‐fear subjects showed a trend in the opposite direction. Similar but largely nonsignificant trends were present for the late wave. Heart rate reactions of both groups in the foreperiod included an early deceleration, acceleration, and a late deceleration. Among high‐fear subjects both the acceleratory and late deceleratory limbs were greater preceding mutilation than neutral slides. In contrast, low‐fear subjects' reactions lacked the acceleratory reaction and did not vary as a function of type of warning signal. These results, therefore, indicate differential autonomic patterns of anticipation of affective stimulation as a function of individual differences in fear.