Working-memory load as a factor determining the safety performance of construction workers

Cognitive processes have been found to contribute substantially to the human errors that lead to construction accidents. Working memory is a cognitive system with a limited capacity that deals with storage and active processing and is critical to a number of different processes. As a departure in construction industry research, this study correlates attentional allocation (measured via eye tracking) with working memory to assess workers' situation awareness under different scenarios that expose workers to various hazards. To achieve this goal, this study merges research linking eye movements and workers' attention with research focused on working-memory load and decision making to evaluate what, how, and where a worker distributes his/her attention while performing a task under different working-memory loads. Path analysis models then examined the direct and indirect effect of different working-memory loads on hazard identification performance. The independent variable (working-memory load) is linked to the dependent variable (hazard identification) through a set of mediators (attention metrics). The results showed that the high-memory load condition delayed workers' hazard identification. The findings of this study emphasize the important role working memory plays in determining how and why workers in dynamic work environments fail to detect, comprehend, and/or respond to physical risks.