A Model for Combination of External and Internal Stimuli in the Action   Selection of an Autonomous Agent
  This paper proposes a model for combination of external and internal stimuli for the action selection in an autonomous agent, based in an action selection mechanism previously proposed by the authors. This combination model includes additive and multiplicative elements, which allows to incorporate new properties, which enhance the action selection. A given parameter a, which is part of the proposed model, allows to regulate the degree of dependence of the observed external behaviour from the internal states of the entity. 
Pedro Pablo Gonzalez Perez, Jose Negrete Martinez, Ariel Barreiro   Garcia, Carlos Gershenson Garcia