38th International Symposium of the GRSNC
Abstracts
  ABSTRACT
NO.
24

DECISION-MAKING AND THE DYNAMICS OF DEATH

T. MORVILLE, O. HULME
University Copenhagen, Danish Research Centre for Magnetic Resonance, Copenhagen, Denmark.

All biological agents face the lifelong problem of maintaining their physiological states within the narrow bounds compatible with survival. To maximise survivorship up to a given phase of life (e.g. sexual maturity) the agent must, by means of their own behaviour, steer their homeostatic trajectory such that the product of all attendant survival probabilities is maximised. This mapping between homeostatic states and survival probabilities, as well as the multiplicative dynamics of those survival probabilities, places fundamental constraints on the valuation of physiological states and their optimisation via decision-making. Here we present a simple normative framework in which homeostatic states are defined and valued as a function of the force of mortality acting on an intra-species ensemble. We show that fitness-optimal decision-making must satisfy two criteria: First, the agent must have access to a well-approximated survival likelihood function, mapping homeostatic states to survival probabilities. This entails that fitness-optimal agents act ‘as if’ they have access to the ensemble level mortality rates for candidate homeostatic paths. Second, the agent must maximise the expected time-average growth of the survival probabilities, by computing the expectation value of the logarithm of the survival probabilities for any homeostatic prospect. We show that this strategy is unique in its optimality, and predicts that all biological agents should be risk averse with respect to the survival probabilities latent to all homeostatic states. We will discuss the ramifications this has for neural encoding and evaluation of homeostatic states.

 

Contact information:
Danish Research Centre for Magnetic Resonance, University Copenhagen,
Kettegaard Allé 30, Hvidovre, Copenhagen, Denmark, 2650
tobiasm@drcmr.dk



Groupe de recherche sur le système nerveux central

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