The presented work is concerned with the wide research field of the Ambient Intelligence systems. These systems, also called Smart Spaces (SS), are designed to provide users with augmented services that do not need intensive and invasive interaction efforts. To obtain this, SS main functionalities are sensing, analyzing, deciding, acting / communicating. In the scope of this wide research field, this paper particularly deals with the analysis task through the study of a theoretical biologically inspired brain model and with the deciding and communicating tasks through the description of a rule enginebased message customization system. Virtual Characters (avatars) displayed on the user’s device represent the final front-end of the system. This choice is due to the high expressive capabilities guaranteed by this kind of communication means, able to enrich the message content with prosody, facial expressions, gestures and to make the communication more effective. Through examples and architecture diagrams, our solution for the problem of the context awareness-based parameterisation of the system reaction is explained
