In this paper a simulation model for visual attention is discussed and formally analysed. The model is part of the design of a cognitive system which comprises an agent that supports a naval officer in its task to compile a tactical picture of the situation in the field. A case study is described in which the model is used to simulate a human subject’s attention. The formal analysis is based on temporal relational specifications for attentional states and for different stages of attentional processes. The model has been automatically verified against these specifications.