Temporal uncertainty, anticipation time, and cognitive coping under threat

The effects of temporal uncertainty, anticipation time, and coping orientations on anticipatory reactions to an inevitable electric shock were investigated. One hundred eight male subjects were randomly assigned to the experimental conditions: they knew or did not know (temporal uncertainty) exactly when shock would occur; they waited either 1, 3, or 12 minutes for the shock, and were given either a vigilance, avoidance, or no orientation for preparing for the shock. Physiological measures were recorded continuously and pre- and post-trial questionnaires were completed to assess thoughts and feelings. Temporal uncertainty and anticipation time interacted to affect stress reactivity--i.e., as shock became imminent, temporal uncertainty led to the increased use of avoidant (as opposed to vigilant) modes of coping and was associated with a progressive lowering of reactivity, especially under the longer anticipation times. The results are consistent with the theory that coping processes mediate stress reactions under conditions of threat.