“Smells detonate softly in our memory like poignant land mines hidden under the weedy mass of years.” ~ Diane Ackerman
Close your eyes and think about your last visit to a movie theater. Try to recall the smells, the sounds, the overall atmosphere. Chances are the memories will be flat and incomplete. When people consciously attempt to remember something they focus on the details, not the feelings or emotions.
However, if you were led blindfolded into a closed movie theater, you would immediately know where you were by the lingering smell of popcorn and the unique smell of carpets trod on daily by thousands of feet. You may even think instantly of a particular movie.
Our noses are assaulted daily by an assortment of smells, both natural and artificial, pleasant and obnoxious. You catch a whiff of fresh-cut grass, school glue, pumpkin pie, fresh laundry, pool chlorine, or winter air, and suddenly you experience a flurry of memories, often from your childhood. What is it about smells that can trigger memories so strong and real it feels like you’ve been transported back in time?
Odor-cued memory, which tends to be stronger and more emotional, is known as “odor-evoked autobiographical memory”. Research shows that odors, more than cues from our other senses, are especially effective as reminders of past experiences.
“Smells do bring back memories,” says Dr. Ken Heilman, James E. Rooks Jr. Distinguished Professor Neurology and Health Psychology at the University of Florida and a member of AAN. “Smell goes into the emotional parts of the brain and the memory parts, whereas words go into thinking parts of the brain.” This could explain why memories sparked by smell feel nostalgic and emotional, rather than concrete and detailed.
The act of smelling something, anything, is remarkably like the act of thinking. Immediately at the moment of perception, you can feel the mind going to work, sending the odor around from place to place, setting off complex repertories through the brain, polling one center after another for signs of recognition, for old memories and old connections. – Lewis Thomas
The reason may be due to the way your brain processes odors and memories. Smells get routed through your olfactory bulb, the smell-analyzing region in your brain, which processes the signal and then passes information about the smell to the limbic system, which includes your amygdala and hippocampus, the regions of the brain that handle memory and emotion. So with scents, you have all this extra processing even before you have conscious awareness of the scent.
Your body also has far more receptors (at least 1,000) for smells than it does for other senses, like sight (four) and touch (at least four). What this means is you can differentiate between many different types of smells, even those you may not have the words to describe.
Speaking of describing smells, can you imagine trying to describe the smell of a rose to someone who has never had the ability to detect odors? How would you do it? It is very difficult to describe a particular smell, even to people who have no olfactory problems. The best we can do to describe a smell is to say that it is “like” or “similar to” another smell. Describing smell is as difficult as trying to describe the look of a rose to someone who has been blind since birth.
What about those suddenly deprived of their sense of smell, a condition known as anosmia? Given that our sense of smell clearly plays an important part in our psychological make-up, its absence can have a profound impact. Anosmia sufferers often feel isolated and cut-off from the world around them and experience a ‘blunting’ of the emotions. Smell loss can affect one’s ability to form and keep up close personal relationships and can lead to depression. Looking at the strong connection between smell and memory, it’s obvious that losing one’s sense of smell can result in the loss of an important sentimental pathway to memories.
Our sense of smell also provides us with a very important early warning system when it comes to objects or situations that may cause us harm. Food that has gone bad may look okay to the naked eye, but the smell it gives off tells us not to eat it. The smells of decaying food, raw sewage, gas, smoke, and ammonia are obnoxious to us because our bodies are warning us of danger.
However, smells can also cause physiological arousal and trigger trauma-related flashbacks, especially in people with PTSD (post-traumatic stress disorder),.Imagine, if you will, a woman being assaulted and raped by a man wearing a strong cologne. Years later, she is walking through a mall with friends when she smells that cologne and it triggers such a vivid memory that she panics and has to leave the mall, leaving her friends baffled.
On a more personal level, smell is extremely important when it comes to the attraction between two people. Research has shown that our body odor, produced by the genes which make up our immune system, helps us subconsciously choose our partners. In fact, kissing is thought by some scientists to have developed from sniffing; that first kiss being essentially a primal behavior during which we smell and taste our partner to decide if they are a match.
Physical attraction itself may literally be based on smell. We discount the importance of scent-centric communication only because it operates on such a subtle level. “This is not something that jumps out at you, like smelling a good steak cooking on the grill,” says Randy Thornhill, an evolutionary psychologist at the University of New Mexico. “But the scent capability is there, and it’s not surprising to find smell capacity in the context of sexual behavior.” As a result, we may find ourselves drawn to the counter attendant at the local drugstore, but have no idea why—or, conversely, find ourselves put off by potential dating partners even though they seem perfect on paper.