Beyond the Candles: Behind the Smell

As you light up your scented candle, lay back and relax, you might have wonder at times what is it in our human brain that makes us smell, causes us to like or dislike certain scents, and seems to encourage our general attitude towards our olfactory environments? In other words, what does it really mean to be able to smell?

In the top part of our nasal passages, there are two yellow-tinted patches hosting about five or six million tiny cells, combined. These are our smell receptors, and the number of cells is directly related to the acuteness of our smell. For example, sniffing expert animals, such as dogs, have about 44x more of these “smell-cells.” And although we cannot begin to compare to our canine friends in this regard, sense of smell is an integral aspect of our daily existence.

Inside of our brains, each smell input is registered and processed at two different levels, in two specific centers. Even before the olfactory sensation enters our cerebral cortex, prompting our cognitive recognition of the smell, the limbic system of our brain is engaged and stimulated. The limbic system is the seat of the rawest of human emotion.

In everyday terms, this means that even before you are able to recognize that you smell something, and decide on what that smell is, the fact is that your body has already emotionally reacted to the sensation. In turn, this primary emotional reaction is going to affect the thought processes involved at the higher cortex levels of perception, influencing the thoughts of pleasantness and unpleasantness.

However, the positive and negative perceptions of smell are not entirely emotional-based. Familiarity plays a very important role in whether we find certain smells pleasant or unpleasant. In many studies, people labeled smells as pleasant, when they were able to readily recognize the source of the smell.

Finally, not all smells are created equal, and nor are all “smellers.” Women tend to significantly outperform men in scent acuteness and sensitivity. Also, we know that sense of smell deteriorates with age, beginning as early as late teens. Yet, there is also good news, which is that practice makes perfect even when it comes to smelling. Through continual stimulation, we can both improve our sense of smell and also prevent its decline with age.

So, let’s keep the scented candles burning and give our brains a good workout.