Human Performance in Context: Exploring the Effect of Social Support on Vigilance

Over many decades, vigilance research has consistently found that performance on vigilance tasks decline over time (i.e., the vigilance decrement; Davies & Parasuraman, 1982), and that performing a vigilance task is both mentally demanding and stressful (Warm et al., 2008). Researchers have subsequently implemented a wide range of interventions to both understand and attempt to attenuate the vigilance decrement and its associated affective effects. Among these efforts, little attention has been devoted to understanding the effects of the social environment on vigilance. Nonetheless, a handful of studies have indeed suggested that the presence of others can affect performance, workload, and stress in vigilance. The present dissertation sought to extend these findings by examining the effect of social support on vigilance, a novel form of social presence in vigilance research, based on findings that the provision of social support may improve performance on cognitive tasks. 236 participants were randomly assigned to complete a cognitive vigilance task either alone or in one of seven social presence conditions: supportive or non-supportive observer, supportive or non-supportive co-actor, independent co-actor, evaluative observer, or merely present observer. Regarding the novel supportive and non-supportive manipulations, results indicated that receiving non-supportive statements resulted in a more conservative response bias than supportive statements, but that receiving supportive statements resulted in higher perceived effort. Additionally, receiving statements from a co-actor, regardless of the type of statement, resulted in higher median response times. In comparing the novel manipulations to existing manipulations of social presence in vigilance, participants in the non-supportive observer condition outperformed those in the independent co-actor and mere presence conditions. The results of this dissertation thus imply that verbal interactions during vigilance tasks – and the supportive or non-supportive nature of those interactions – can affect performance and workload differently than non-verbal forms of social presence.