When you take a deep whiff of your morning coffee, the smell of those fresh-roasted beans darts into parts of the brain responsible for emotional and memory processing, but our other senses don’t work in the same way. That’s why smell can trigger a happy memory more quickly than touching the hot coffee mug or tasting that first sip.

Scientists suggest that there are a number of reasons why our bodies treat scent differently than other senses. From hunting and gathering food to finding healthy mates, linking smells with memories that stir up desire, happiness, or even fear is biologically useful for humans. Humans have one other thing to consider when scent is at play: context is key. Experiments have shown that while scents are important to our animal brains, our highly visual nature can mingle with and directly influence our reaction to scents. Audio cues that align with scents matter, too.

To understand how important context is to scent marketing, researchers suggest that labelling a scent good or bad is as important as the scent itself. In one experiment, subjects were asked to inhale the scent of cheese. Those who were told it was cheese were delighted with the scent. But when researchers told other participants that the container was filled with vomit (even though it was the same cheese), people reacted with disgust. Psychologist Johan Nordstrom drew the conclusion that ‘you can go from extremely positive to extremely negative just by changing the label.’