Comparative analysis of cognitive load associated with passive and active back-support exoskeleton use for...

Exoskeletons have the potential to reduce workplace injuries; however, their use could increase cognitive load. While prior studies have explored the cognitive load impacts of passive and active back-support exoskeletons, research comparing their effects in construction-related tasks remains limited, particularly using electroencephalogram theta brainwave activity as a cognitive load indicator. This study assesses and compares the cognitive load implications of active and passive back-support exoskeletons relative to a baseline (i.e., without an exoskeleton) during construction framing tasks.

A within-subjects experimental method was employed, where participants performed a carpentry framing task under three randomized conditions: without an exoskeleton, with a passive back-support exoskeleton, and with an active back-support exoskeleton. Electroencephalogram (EEG) theta brainwave activity and NASA TLX subjective evaluation were captured to evaluate cognitive load.

The central sulcus, a region associated with motor control and cognitive processing, exhibited a significantly higher cognitive load during active back-support exoskeleton use. Additionally, both exoskeletons significantly increased cognitive load compared to no exoskeleton usage but did so in different ways: the passive back-support exoskeleton primarily increased load in the frontal region, indicating working memory depletion during dynamic, physically demanding tasks. Conversely, the active back-support exoskeleton elevated cognitive load due to rapid augmentation, which required greater motor control and cognitive processing. The subjective evaluation results indicate increased frustration among users, particularly with the passive exoskeleton, corroborating the EEG findings.

The study found that both exoskeletons increased cognitive load compared to no exoskeleton use, with the active one affecting motor control and cognitive processing more significantly.

The findings contribute to the underexplored intersection between cognitive neuroscience and construction ergonomics, providing task-specific knowledge to guide stakeholders in selecting suitable exoskeletons for various tasks. The study further lays a foundation for future research on construction activities with diverse ergonomic challenges and cognitive demands.