We introduce the distinction between a strategic (or motivational) level of behaviour, where different motivations compete with each other for the control of the behaviour of the organism, and a tactical (or cognitive) level, where the organism executes the activities aimed at reaching the goal decided at the strategic level. To illustrate and operationalise this distinction we describe three sets of simulations with artificial organisms that evolve in an environment in which in order to survive they need either to eat and drink, or to eat and avoid being killed by a predator. The simulations address some simple aspects linked to the strategic level of behaviour, i.e. the role played by the environment in determining what are the motivations driving an organism and what is the strength of each of these motivations. Other phenomena investigated are the usefulness for the organism's brain to receive information from its own body (e.g., in the form of hunger or thirst), how inter-individual differences among individual organisms may concern both the strategic and the tactical level of behaviour, and how the unsolved competition between very strong motivations can lead to pathological states such as depression.

Inspec keywords: biology

Other keywords: pathological states; tactical behaviour level; strategic behaviour level; artificial organisms; motivations; inter individual differences; depression; organism behaviour

Subjects: Systems theory applications in biology and medicine