Understanding mental workload is central to ergonomics, as it affects performance and well-being. Eye-based and physiological measures offer promising workload indicators, yet their validity in collaborative contexts, where task and teamwork demands interact, remains underexplored.

This experimental study examined the effects of two components of workload during team tasks, team mental workload (teamMWL) and task mental workload (taskMWL), on ocular, electrodermal, and cardiovascular activity. Thirty participants completed a dual-task paradigm involving verbal interaction with a simulated team alongside a reaction-time task using stimuli from a cooperative video game. Within a 2 × 3 repeated-measures design, teamMWL and taskMWL were manipulated, and multilevel mixed-effects models were used to analyze their effects on physiological markers. Related variables were grouped using exploratory factor analysis, yielding latent factors representing underlying physiological phenomena. These factor-derived variables were entered into the models to analyze workload-related physiological responses. Analyses included control variables to account for confounds (e.g., gaming experience), and manipulation checks verified the effectiveness of the workload manipulations.

While electrodermal activity was not sensitive to changes in teamMWL or taskMWL, the two workload components exerted distinct, sometimes opposing, effects on ocular and cardiovascular metrics. For instance, a factor representing fixation behavior decreased with higher teamMWL (β_standardized = -0.33, FDR-corrected p = .001) but increased with taskMWL (β_standardized = 1.03, FDR-corrected p < .001). These patterns likely reflect different coping strategies or by-products of task and teamwork demands, indicating differential impacts of task- and teamwork-related workload on visual attention and autonomic activity.