Everyone knows that certain smells can trigger memories. You’re walking down a boardwalk and get a whiff of someone’s sunblock and suddenly you remember going to the pool with your friends as a kid. I have always wondered why these memories seem to be more vivid then other memories we have. For example if a see an old picture I can sort of remember taking it but just smelling the sunscreen I was wearing that day paints a vivid image in my head. It turns out that this particular type of memory is called an olfactory memory. The reason that olfactory memories are so powerful is due to the position of the olfactory nerve in the brain. It is located very close to the amygdala, which is the part of the brain that deals with experience of emotion and emotional memory. The olfactory nerve is also close to the hippocampus, which anyone in psych will be able to tell you is heavily associated with memory. So the location of this nerve is in prime real estate for creating powerful memories that are heavily tied to emotion. This explains why went you recall a memory due to smell its typically either very happy or sad.

Many people have noticed that majority of the memories triggered by smell seem to take place in their childhood. A study done by a writer for psychological science discovered, that the peak age for memoires retained by smell occurs at around 5 years old. “It was really, totally clear that when they recollected a specific memory, that memory was localized to the childhood period,” The memories were also more emotional and more vivid than memories brought up by visual or verbal cues.” The study also discovered that the brain tends to imprint the earliest exposure to a certain smell with its memory that it forms. So take the sunscreen I mentioned earlier, I’m certain that I have used it later in my life, but every time I smell it I am still reminded of my very early childhood and my mother slathering me in the stuff. This is because olfactory memory is not affected by retroactive interference, which is when new memories formed such as learning a new language interfere with older memories such as a previously spoken language. This is why people have trouble remembering older information but have no difficulty remembering something from their very early childhood that is associated with a smell.

A study reviewed by Macalester University discovered, that neurological disorders such as Korsokaffs syndrome, Alzheimer’s disease, and Parkinson’s disease, show less impairment for olfactory memory ability. Basically people who have difficulty retaining memories in general still have an easier time retaining olfactory memories. What is important about this discovery is it proves that olfactory memory is very different and more powerful than the many other kinds of memory we as humans have.

So overall it isn’t random when we smell things and have a powerful memory, its due to the olfactory nerve’s perfect position in our brain.

http://www.macalester.edu/psychology/whathap/UBNRP/Smell/memory.html

http://www.psychologicalscience.org/index.php/publications/observer/2012/april-12/fragrant-flashbacks.html

http://psychology.about.com/od/memory/ss/ten-facts-about-memory_8.htm