Providing real time analysis of the huge amount of data generated by computer vision algorithms in interactive applications is still an open problem. It promises great advances across a wide variety of elds. When using dynamics scene analysis algorithms for computer vision, a trade-o must be found between the quality of the results expected, and the amount of computer resources allocated for each task. It is usually a design time decision, implemented through the choice of pre-de ned algorithms and parameters. However, this way of doing limits the generality of the system. Using an adaptive vision system provides a more exible solution as its analysis strategy can be changed according to the new information available. As a consequence, such a system requires some kind of guiding mechanism to explore the scene faster and more e ciently. We propose a visual attention system that it adapts its processing according to the interest (or salience) of each element of the dynamic scene. Somewhere in between hierarchical salience based and competitive distributed, we propose a hierarchical yet competitive and non salience based model. Our original approach allows the generation of attentional focus points without the need of neither saliency map nor explicit inhibition of return mechanism. This new real- time computational model is based on a preys / predators system. The use of this kind of dynamical system is justi ed by an adjustable trade-o between nondeterministic attentional behavior and properties of stability, reproducibility and reactiveness.