1. Computational cognitive modelling
2. Cognitive models of language:
   • Conceptualisation for language
   • Language production/generation
   • Generation of referring expressions
   • Dialogue
3. Cognitive models of the foundations of mathematics
4. Cognitive models of affect and emotion

At the heart of Cognitive Science lies the assumption that human cognition can be explained by computation. (The strong form of this claim is that cognition is computation.) Being an Informatician I take this assumption literally and try to build computational models that explain (a part of) cognition. This approach goes back to Herbert Simon and Alan Newell and is called computational cognitive modelling.

I am particularly interested in the interaction of the computational model and the environment – what these days usually goes by the name of embodiment or embodied cognition. Because cognition is not directly accessible to scientific investigation much can be learnt from observing the model –environment interaction, in particular the temporal interleaving of changes occurring in the world and the behaviour of the system.

If what sets humans apart from other animals is language, no account of cognition can be complete without a sound understanding of language. Although there is the discipline of Computational Linguistics that develops computational models for processing language and the discipline of Psycholinguistics that researches the cognitive foundations of language use, there is little contact between the two due to the different research traditions and established methodologies. Computational cognitive modelling is the tool to bridge this gap.

With regard to language I am particularly interested in conceptualisation, that is, the higher-level processes of language production/generation*. A key to understanding the processes of conceptualisation is the incremental (piecemeal) mode of processing used by humans, which makes it possible to use the above mentioned method of investigating the model–environment interaction (my PhD thesis). More recently, I have been working on the use of intonation in dialogue and how the use of referring expressions is influences by properties of the task environment (see this paper).

Another distinctly human ability is the use of mathematics, and mathematics seems to be intricately linked with the human language ability and the embodied nature of the human mind. In a newly started project I am working on how humans are able to develop and use mathematics. Starting from work of Lakatos and Lakoff & Núñez I am working on developing a computational cognitive model of mathematical exploration.

Cognition is traditionally seen as being rational and distinct from or even diametrically opposed to emotions (also often referred to as affect). More recently, however, it has become clear that emotions are an integral part of cognition and that in order to make timely decisions in a given environment a functioning affective system is crucial (see, for example, the work by Damasio). I have in particular been working on how different levels of stress allow humans to keep up with differences in task demand (see this paper).