  The course of an epidemic is not only shaped by infection transmission over
face-to-face contacts, but also by preventive behaviour caused by risk
perception and social interactions. This study explores the dynamics of coupled
awareness and biological infection spread within a two-layer multiplex network
framework. One layer embodies face-to-face contacts, with a biological
infection transmission following a simple contagion model, the SIR process.
Awareness, modelled by the linear threshold model, a complex contagion, spreads
over a social layer and induces behaviour that lowers the chance of a
biological infection occurring. It may be provoked by the presence of either
aware or infectious neighbours. We introduce a novel model combining these
influences through a convex combination, creating a continuum between pure
social contagion and local risk perception. Simulation of the model shows
distinct effects arising from the awareness sources. Also, for convex
combinations where both input sources are of importance, awareness cascades
that are not attributable to only one of these sources, emerge. Under these
conditions, the combination of a small-world face-to-face and a scale-free
social layer, but not vice versa, make that the extent of the infections
decreases with increasing transmission probability.
