The paper “The complexity and commonness of the two-process model of sleep regulation from a mathematical perspective“, co-authored by Anne Skeldon and Derk-Jan Dijk (Surrey Sleep Research Centre), has been published in the Nature journal NPJ: Biological Timing and Sleep (open access link here). The paper was invited for a special issue on sleep regulation. The two-process model (2pm) of sleep regulation was written down more than 40 years ago and provides the conceptual framework that underpins much of our understanding of sleep regulation today. Anne and Derk-Jan have brought a unique mathematical perspective to the dynamics and meaning of 2pm. In the paper, they set out many of the ideas that they have been working on over the last decade or so along with various collaborators, including Gianne Derks (Leiden) and Surrey PhD student Matt Bailey. The paper expands on themes which they have developed elsewhere and is aimed at a more general audience than some of their more technical publications. Importantly, they set out more explicitly the hierarchical coupled oscillator with feedback nature of the system. Accompanying the paper is a Matlab app which enables people to explore the dynamics of the 2pm (github link here). The screenshot below shows the interface of the Matlab app.