Towards a Multimodal Measure for Physiological Behaviours to Estimate Cognitive Load

We present an experiment investigating the relationships between different physiological measures, including Mean Pupil Diameter Change, Blinking-Rate, Heart-Rate, and Heart-Rate Variability to inform the development of a measure to estimate Cognitive Load. Our experiment involved participants performing a task to spot correct or incorrect words and sentences which successfully induced Cognitive Load. Our results show that participants' task performance predicts their subjective rating of Cognitive Load and that there was a decrease in participants' performance with an increase in Cognitive Load. Furthermore, Mean Pupil Diameter Change was able to predict Blinking-Rate, and Heart-Rate was able to predict Heart-Rate Variability. This prediction is evidence that collecting data on physiological behaviours synchronously and analysing the trends can be an effective way of estimating Cognitive Load, and will help the future development of an online measure of Cognitive Load useful for responsive user interfaces.