A single cell slime mold makes decisions without a central nervous system
Pour water into a maze (or create a potential difference across a conductor) and you'll see that as new current flows in, it doesnt explore every pathway but takes the correct path through.This intelligent behavior arises from the simple compulsions things to reach equal potential.The slime mold experiments are  cool because they connect simple compulsions with emergent intelligent behavior in an organism. I have wondered if it's the same for us, if conciousness is really just the sum of all our simple compulsions, arising from basic rules - like is water "conscious" of wanting to seek it's own level, ions conscious of wanting to react, etc, and together that makes up what human conciousness is?