A very general approach to describe the dynamics of the brain is through differential equations. Instead, one could choose a more restrictive approach and describe it as an optimization. Can we assume that observed human behavior can be explained well as an optimization of an unknown cost function? What is the scientific evidence for and against this?
Quirin et al (2020) have developed a dynamic systems approach that uses optimisation consider behaviour and personality.
Quirin, M., Robinson, M. D., Rauthmann, J. F., Kuhl, J., Read, S. J., Tops, M., and DeYoung, C. G. (2020) The Dynamics of Personality Approach (DPA): 20 Tenets for Uncovering the Causal Mechanisms of Personality. Eur. J. Pers., https://doi.org/10.1002/per.2295.