The ASMO Cognitive Architecture has been developed to support key capabilities: attention, awareness and self-modification. In this paper we describe the underlying attention model in ASMO. The ASMO Cognitive Architecture is inspired by a biological attention theory, and offers a mechanism for directing and creating behaviours, beliefs, anticipation, discovery, expectations and changes in a complex system. Thus, our attention based architecture provides an elegant solution to the problem of behaviour development and behaviour selection particularly when the behaviours are mutually incompatible. Keywords. Cognitive Architecture, Attention, Self-modification, ASMO, Dynamic Behaviour