. Why do we need a hedonic/incentive system? Why isn’t homeostatic control sufficient?

A hedonic system serves to put forth goal-directed actions. Homeostatic control, on the other hand, would not keep getting activated if it is already stable, or nearly stable, as its purpose is reducing error signals to maintain within an acceptable range from the set reference signal. Whereas, hedonic systems activate every time we “like” or “want” something. According to Berridge and Kringelbach’s paper: Pleasure Systems in the Brain” hedonic/incentive systems have evolutionary origins. They argue that these hedonic system reactions were selected by evolution due to their functions related to survival. For instance, it is due to hedonic systems that we are able to selectively choose the food we eat and are able to discover what we like and do not like, via orofacial “liking” responses. Due to this, we are able to consume the more energy dense foods and also choose the ones most appealing to us. However, if we would just use Homeostatic control, we would consume enough food to reduce our energy deficiency without considering what we would consume. If we consider that homeostatic control would simply make us consume enough food, we would not be taking into consideration calorie intake or even if a food is of our liking or not. Thanks to pleasure systems, monkeys, humans and even rats are able to display orofacial responses of liking and disgust, which serve to classify foods we should consume and ones we should not.

Thinking evolutionarily, this could have begun as the ability to discern, based on taste or smell, if any berries or food sources were safe to consume or not. Thus, the ability to activate the pleasure system w