Abstract
Interest in workload transitions is centered on the hypothesis that transitions from one level of task difficulty to another may negatively impact performance on those tasks, and result in potentially critical impacts on professionals such as air traffic controllers and emergency medical staff. The current study sought to determine the effect of workload transitions on participants’ neurophysiological signals and performance. Participants completed trials in the Air Force Multi-Attribute Task Battery (AF-MATB; Miller, 2010), while Electroencephalography (EEG), Electrocardiography (ECG) and Electrooculogram (EOG) signals were recorded. All participants completed AF-MATB trials that delivered consistently low or high task difficulty, and trials that transitioned from an easy level to a difficult level and vice versa. Additionally, participants completed the NASA Task Load Index to assess subjective workload, and the shortened Dundee Stress State Questionnaire to measure subjective task-related stress during their testing sessions. Analyses of the performance data provide limited support for a negative impact of transitions from hard-to-easy, and the analysis of both the NASA Task Load Index and of the shortened Dundee State Questionnaire did not reveal any significant differences related to workload transitions. Analysis of the EEG data revealed that temporal gamma oscillations rapidly changed following a transition and settled after easy-to-hard changes in task difficulty, but settled more slowly after the task transitioned from hard-to-easy. Frontal theta oscillations, in contrast, exhibited consistently rapid settling which may indicate rapid changes in working memory utilization and conflict resolution (Gevins, et al., 1997). These EEG results suggest potential for further research.