Epistemic Review
I have experienced this many times. When I’m feeling hungry, the smell of food is always appetizing and rewarding. Even if it’s food that I don’t like or the kind of food that I don’t eat, the smell captures me. After all, it’s not uncommon that someone would end up drooling over the smell of piping hot food that’s freshly prepared. Funnily enough, the opposite happens when I have eaten satisfactorily. Once my hunger is satiated, the smell of food is not rewarding anymore. It doesn’t matter if it’s even pizza, the smell is noxious or at best, just what I do not want to smell
Question
What causes this feeling? Is there a connection between our sense of smell and our motivation for craving and the reward we get from satisfying said craving?
Recent studies have found a connection in the brain - The connection between the olfactory tubercle (OT) and the periaqueductal gray (PAG) strongly determines this feeling. The former is responsible for our sense of smell (olfaction) and the latter is part of our Reward System. The stronger the connection between the two, the stronger this feeling I am experiencing and thus, the healthier I am. I can confidently rely on my body giving me accurate signals that I’m full and I don’t need to eat anymore. True enough, I can be repulsed by food when I’m full because I can’t be okay with the smell. It prevents me from overeating
If the connection was weaker, then even if I would be full, I would still experience feelings of reward and pleasure when I am smelling food, which will lead me to eat more than what my body has already asked for. I end up overeating and that’s a sure-fire ticket to obesity in the long run
- Researchers at Northwestern Medicine used MRI brain data gathered from the Human Connectome Project to identify the connection between the OT and the PAG and map the strength of the circuity that joins them together. They then replicated their findings on a smaller brain dataset that was collected in the NWU lab
Recently, a new brain receptor called latrophilin-1 has been identified that controls food intake