On choosing to make aversive events predictable or unpredictable: some behavioural and psychophysiological findings

Choice and psychophysiological correlates of choice were examined for 36 subjects in a laboratory paradigm where one of two visual display channels could be selected. The first gave warning of an aversive event (shock or noise). The second channel provided an interesting distraction but gave no warning of an aversive event. The subjects were led to believe that aversive events were either avoidable, possibly avoidable or unavoidable. The events were also described as differing in likelihood from trial to trial. Results suggested that threat of unexperienced events produced more monitoring for warning. Controllability and likelihood enhanced choice of monitoring though male subjects showed some anomalous results. There was some tentative evidence to suggest that subjects scoring internally on the locus of control dimension may show more definite preference for one or other channel. Monitoring was associated with greater subjective tension, tonic heart-rate and skin conductance fluctuations. The pattern of correlations among arousal and choice indices across trials suggested that the cardiovascular measure reflected the vigilant aspect of active coping whilst the subjective tension and electrodermal measures reflected affective aspects of arousal. Results are discussed in terms of the literature on coping strategies and stress, and possible applications of experimental work on controllability.