THE ROLE OF CHOICE AND INDIVIDUAL DIFFERENCES IN THE MITIGATION OF NOISE AND TASK STRESSORS ON VIGILANCE H.C. Neil Ganey', James L. Szalma1'2,Peter A. Hancock''2, Mustapha Mouloua', Anna Connellyl, Joseph Dalton', and Fleet Davis' 'MURI-OPUS Laboratory Institute for Simulation and Training University of Central Florida Orlando, FL 2 The present study investigated the effects of perceived control over aspects of a task (difficulty) on stress and workload in a vigilance task. Additionally, individual differences in dispositional factors and coping strategy chosen by the operator were considered. Prior research has indicated that pessimism has an effect on the level of experienced stress. Additionally, coping strategies have been linked to stress and workload ratings in a variety o f t asks (Matthews & Campbell, 1998). While these factors have been investigated independently, as is frequently the case, their complex interaction has remained unaddressed. In the study, we found that optimism was negatively related t o task engagement, though i t was p ositively related t o distress. Additionally, it was found to be a predictor of task-focused coping behaviors. More conscientious people were less likely to engage in task-focused or emotion-focused coping. Those who were less pessimistic tended to have heightened worry over the task. INTRODUCTION Individual differences in operator characteristics influence vigilance performance and the stress experienced by people engaged in such tasks (Berch & Kanter, 1984; Helton, Dember, Warm & Matthews, 1999). Some of those differences, such as personality traits and response strategy, have been shown to influence perceived workload on a variety of tasks (Damos, 1988). One of the goals for the present investigation was to extend the findings of Szalma (2002) on the impact of dispositional pessimism, and differences in the coping strategies observers employ, on stress and workload of vigilance. In this study these effects were extended to included noise stress and the impact of perceived control on the workload of stress and vigilance. Following Dember, Galinsky, and Warm (1992), perceived control was manipulated by providing participants the illusion that they could choose the difficulty level of the vigil. Dember and his colleagues observed that such a manipulation attenuated the vigilance decrement, and it is possible that perceptions of control may also reduce the workload and stress of vigilance. Pessimism and Performance In addition to predicting stress-state, Szalma (2002) also observed an impact of pessimism on coping strategies adopted by observers. As Matthews and Campbell (1998) have noted, the study of coping strategies for dealing with workload and stress has received little attention in human factors. To address this gap, they developed a coping inventory for task stressors (CITS) for immediate post-task assessment of coping strategies that individuals use. Three strategies were identified based upon Lazarus and Folkman's (1984) transactional theory of stress. These are task-focused coping, in which the individual copes with stress through behavior aimed at changing the stressful situation, emotion-focused coping, which is directed a t changing one's e motional response, and avoidance-focused coping, in which the individual diverts attention away from the task. Individuals high in pessimism tend to engage in emotion-focused coping, while optimists tend to use task-focused coping (Scheier & Carver, 1987). Moreover, while Helton and his colleagues (1999) did not directly measure coping strategy, their findings that pessimists reported higher levels of distress and less task engagement suggest that pessimists were employing emotion-focused coping, since post-task distress implies that form of coping, and optimists were more likely to use task-focused coping, since higher task engagement implies use of that strategy (Matthews & Campbell, 1998). Indeed, Szalma (2002) observed that pessimists were more likely to engage in emotion-focused coping, although that variable did not predict the degree of task or avoidant coping adopted by operators. Stress State and Performance Matthews and Campbell (1998) observed consistent patterns of correlation among coping strategies and the post- task stress states of observers, as measured by the Dundee Stress State Questionnaire (DSSQ), a multi-dimensional instrument for assessing transient states associated with mood, arousal, and fatigue (Matthews, et al., 1999). The DSSQ consists of 10 factor analytically determined scales, which load onto three secondary factors that reflect the individual's stress state. Three of the scales reflect Task-Engagement (energetic arousal, motivation, and concentration), three scales \ PROCEEDINGS of the HUMAN FACTORS AND ERGONOMICS SOCIETY 47th ANNUAL MEETING—2003 1078