Network technology, multimedia applications and digital devices have become ubiquitous in our society. Most people have their own information appliances and can easily access various types of information. Big changes are occurring everywhere: in our offices, homes, cars and so on. Unfortunately, the human capacity for processing information is limited. Coping with the mass of information with which we are faced is impossible. Systems must, therefore, estimate users' cognitive loads and make judgements about the most suitable combination of media, modality and the intrusiveness with which information is presented. We propose a basic system architecture that gradually adapts to individual cognitive capability.