A COST-BENEFIT-ANALYSIS OF BEHAVIORAL SEQUENCE ORGANIZATION IN LABORATORY MICE

To test the hypothesis that the actual organization of diurnal and noc turnal behavioural sequences observed in C3H mice tend to maximize a c lassical functional criterion - the net energy gain - artificial behav ioural sequences were defined by reorganization of the acts of actual ones, through application of three Monte-Carlo-type processes (ALT, SE Q and RND). ALT sequences correspond to a random choice of rest/activi ty bouts, and SEQ sequences to a random reorganization of acts in each activity bout. RND sequences correspond to a random choice of rest/ac tivity bouts together with a random choice of acts in each activity bo ut. The net energy gain associated with each of these artificial behav ioural sequences was derived from a computation of the corresponding e nergy inputs by means of a dynamic feeding model - and energy outputs, on the basis of the energy cost of each constituent act. This net gai n was then compared with the net gain corresponding to the actual beha vioural sequence of the animal. The results of RND and ALT sequences s ubstantiate the maximization hypothesis, while those of SEQ sequences reveal individual differences. This suggests the existence of two inde pendent behavioural strategies - choice of rest/activity alternations and choice of acts during an activity bout - as they can lead to antag onist effects on the functional criterion.