Secretory immunoglobulin A reactivity to acute and cumulative acute multi-tasking stress: relationships between reactivity and perceived workload.

The effects of an acute stressor upon secretory immunoglobulin A (S-IgA) were assessed using a task that requires participants to attend and respond to several stimuli simultaneously and is therefore analogous to a variety of working environments. In two studies, the task was administered for periods of 5 min to healthy samples of men and women at two sessions 24 h apart (n = 49) and three times in succession within one session (n = 20). Multi-tasking stress was, at all sessions, associated with increases in S-IgA secretion. Inter and intra-session reliability of pre and post-stress S-IgA measures was observed, although the reliability of stress reactivity data was reduced. Classification of participants as either high or low S-IgA reactors revealed differences in their perceptions of task workload. Low S-IgA reactors consistently perceived the task to be more demanding and frustrating than did those who demonstrated high S-IgA reactivity. We conclude that S-IgA reactivity to stressful situations depends not just upon the task, but also upon individual perceptions of the stressor.