Neurophysiological measures of cognitive workload during human-computer interaction

摘要

Perhaps the most basic issue in the study of cognitive workload is the problem of how to actually measure it. The electroencephalogram (EEG) continues to be the clinical method of choice for monitoring brain function in assessing sleep disorders, level of anaesthesia and epilepsy. This preference reflects the EEG's high sensitivity to variations in alertness and attention, the unimposing conditions under which it can be recorded, and the low cost of the technology it requires. These characteristics also suggest that EEG-based monitoring methods might provide a useful tool in ergonomics. This paper reviews a long-term programme of research aimed at developing cognitive workload monitoring methods based on EEG measures. This research programme began with basic studies of the way neuroelectric signals change in response to highly controlled variations in task demands. The results yielded from such studies provided a basis on which to develop appropriate signal processing methodologies to automatically differentiate mental effort-related changes in brain activity from artifactual contaminants and for gauging relative magnitudes of mental effort in different task conditions. These methods were then evaluated in the context of more naturalistic computer-based work. The results obtained from these studies provide initial evidence for the scientific and technical feasibility of using EEG-based methods for monitoring cognitive load during human-computer interaction.