We all know how pleasurable it can be to eat a piece of chocolate. The first time its smooth richness and tasty cocoa touches our tongue, an area of our brain called the medial frontal lobes becomes activated and our brain rewards us for eating such wonderful tasting food. Obviously, we want to have another, then another, and so forth.
As we continue to eat pieces of chocolate, our brain begins to lessen its activation of our pleasure centers, and we feel less drive to have another piece of chocolate. This is the result of habituation, a decreased physiological or behavioral response following repeated stimulation.
For example, when you first put on your shirt, you notice its presence against your skin. After a few minutes, you no longer notice it for the rest of the day. The brain performs this habituation response all of the time with regard to many different types of stimuli, including to what we eat.
Neuroscientists now have a very good idea about which parts of the brain are responsible for this habituation response, and how your imagination can influence it, therefore influencing the way – and how much – you eat. We also understand why it is so important that our brain responds in this manner.
Our brain wants to help us to survive. In order to survive we all are aware that we need to consume a variety of nutrients, including vitamins, fats, carbohydrates, proteins, and so forth. The best way to achieve this balance of nutrients is to eat a variety of different foods. Thus our brain habituates to even the most delicious foods rather quickly in order to encourage us to try different foods.