Some Antecedents of Directional Fractionation: Effects of "Intake-Rejection," Verbalization Requirements, and Threat of Shock on Heart Rate and Skin Conductance

Following recent contradictory claims in the literature regarding the phenomenon of directional fractionation, the present study was designed to investigate variables related to this differential patterning of autonomic response. Heart rate (HR) and skin conductance (SC) were recorded from 89 male students who either attended to flashing lights or worked a subtraction problem under threat-of-shock or no-shock conditions. Effects of instructions to verbalize later were also investigated. While significant task differences were demonstrated which were consistent with the directional fractionation hypothesis, instructions to verbalize later affected neither HR nor SC. Threat of shock significantly elevated HR during the task only for Ss attending to flashing lights. However, threat of shock significantly raised HR and SC levels immediately after instructions (and preceding the task) when combined with instructions for subtraction. Results were contrary to arousal theory, supportive of Lacey's theory of an “intake-rejection” dimension, and contrary to Campos and Johnson's verbalization findings.