Organisms are designed to engage three basic functions: resource acquisition, defense against accident (e.g., predation and disease), and reproduction. Their lifestyles represent economic strategies, and range in complexity from very simple solitary foraging to the complicated, multi-layered economies of the social vertebrates. The complexities of valuation, decision-making, and lifestyles are parallel over this range. What are the gradations of complexity in behavioral economy, and how are they traversed in evolution?

We describe neuronal circuitry for cost-benefit decisions in foraging behavior of the predatory sea-slug Pleurobranchaea and reproduce it in simulation. The computations resemble those of the most primitive parts of the mammal’s brain, onto which higher consciousness was grafted in evolution. We study the animal’s simple brain and behavior to understand the origins of the esthetic sense, reward experience, and addiction. How did the complexity for social behavior, abstract thought, and self-awareness evolve from the simpler brain?

We combine behavioral analyses, neurophysiological techniques, and computational modeling in an integrated approach to understanding how complex brains evolved from simple ones. A new research thrust analyzes sensory-motor computations of the peripheral nervous systems in Pleurobranchaea and the octopus to understand the coordination of behavior in animals without articulated skeletons, and how nervous system complexity evolved from simplicity.

We produce interactive computational simulations of foraging in virtual entities that make realistic economic decisions by weighing stimulus characters against motivation, and reward learning. Two may be freely accessed for experimentation from https://github.com/Entience/Cyberslug and https://github.com/Entience/ASIMOV. The version ASIMOV illustrates the emergence of addiction processes from the neuronal circuitry of foraging. The most recent addition is the Feature Association Matrix (FAM) to ASIMOV episodic memory, giving it awareness of the past and ability to cognitively map its environment; article link: https://doi.org/10.1016/j.neucom.2024.127812