
Various
techniques to measure situation awareness exist. For example, objective
measures uses accuracy and time to respond to queries as a way of inferring
operator situation awareness. Subjective measures rely on feedback from an
expert or self-ratings to determine situation awareness. Finally, implicit
performance measures are also used and that involves embedding events into
scenarios that would require operators to exhibit specific behaviors.
More
recently, Dr. Frank Durso and colleagues published an article in the Journal
of Human Factors, wherein they discuss
how facial EMG can be used to detect loss of situation awareness (or
confusion).
The experimental set up was such that the participants in the experimental condition listened to a passage and were asked to raise their index finder when they heard something that did not make sense to them. Participants in the control condition raised their finger when they heard an animal being mentioned. Four facial muscles (near the left and right and left eyebrows, the mandiable, and the cheek) were recorded using EMG while participants listened to the passages.
Key
takeaways from the article:
- EMG traces detected confusion in all the participants who reported that they were confused and also in 6 participants who did not report any confusion. This shows that facial EMG is a better detector of loss of situation awareness than self-report measures.
- The facial muscles near the eyebrows were the most effective in detecting confusion.