Quantitative Analysis Of The Effort-Fatigue Tradeoff In The Conceptual Design Process: A Multistate Eeg Approach

Physiological signals are at the core of affective and cognitive engineering methods which aim at providing a more human centric perspective to engineering concepts and systems. Labelling physiological signals with meaningful words such as concentration, fatigue or effort is a hard task. Although those labels are well-documented in the medical and related literature, their meaning gets lost in translation in engineering and design sciences. Multistate analysis of physiological signals aims at alleviating this process by identifying pittfalls and errors backed by hard numerical and statistical evidence. In this paper, we use multistate analysis of EEG signals to revisit the effort-fatigue tradeoff in the conceptual design process. Many rules of thumb and intuitions may exist about the effort-fatigue tradeoff and the goal is to provide a quantitative framework where this tradeoff can bear meaning. Following our multistate analysis, we define different types of fatigue (TYPE 1-5 Fatigue) which behave differently based on our numerical analysis and conclude that fatigue and by extension effort are multidimensional concepts.