People smelled cheese through fancy equipment
The high-tech setup of the actual experiment involved some serious equipment, including a non-ferrous air-dilution injection head and polyvinyl-chloride foot bellows, not to mention an olfactometer, an oxygen mask, a button box, and an fMRI machine to check out what happened in people's brains. Oh, then there were the cheese smells.
Each participant was strapped in and presented with 84 food smells or food smells and photos. This sounds like an interesting olfactory experience, though in reality, only 12 foods were used, half of which were different kinds of cheese. Because the study was conducted in France, it's only natural that one of the non-cheese foods was pâté, and that one of the cheeses was tomme, which you've probably never even heard of.
So what's up with cheese disgust?
After analyzing the brain images from the functional MRI machine, the team saw a few interesting things. First, there was activity in the brain's reward circuit when the "pro" people smelled cheese, but weirdly, that area of the brain was also active when the "anti" people smelled cheese.