a neuroergonomic approach to evaluating mental workload in hypermedia interactions

neuroergonomics could provide on-line methods for measuring mental effort while the operator interacts with hypermedia. we present an experimental study in which 28 participants interacted with a modified version of an existing spanish e-commerce website in two searching tasks (goal oriented shopping and experiential shopping) that demand different amounts of cognitive resources. mental workload was evaluated multidimensionally, using subjective rating, an interaction index, and eye-related indices. eye movements and pupil diameter were recorded. the results showed visual scanning behaviour coincided with subjective test scores and performance data in showing a higher information processing load in goal oriented shopping. however, pupil diameter was able to detect only the variation in user activation during the interaction task, a finding that replicates previous results on the validity of pupil size as an index of arousal. we conclude that a neuroergonomics approach could be a useful method for detecting variations in operators’ attentional states. relevance to industry these results could provide important information for the development of a new attentional screening tool for the prevention of accidents in several application domains.