Making Scents

Making Scents of our Memories

Smells detonate softly in our memory like poignant land mines hidden under the weedy mass of years. Hit a tripwire of smell and memories explode all at once. Diane Ackerman

Considered less developed in humans than other animals, smell still plays a significant role in collecting information about one’s surrounding environment. Through our sense of smell we are able to identify food, other individuals, and even dangers.

There are up to 10,000 separate odors that a healthy individual can identify, and each of these odors must be capable of entering a gaseous state for our senses to be able to detect and identify it. We can smell a piping hot apple pie, for instance, but not the metal pie tin used for baking.

The process of how we smell is complex involving various parts of our brain as well as parts of our nose. Smell and memory are intrinsically linked, since processing odors is directly wired to the limbic system where emotion resides and memory is stored. Of the body’s five senses, smell is the only one with a direct connection to the brain and whose recognition is immediate.

The memory centers of the brain, the amygdala and hippocampus, are where odor messages are first analyzed. It is this memory-smell connection that explains why a whiff of freshly-mimeographed paper might summon a distant childhood memory of coloring in an first-grade classroom or why the smell of Wrigley’s Spearmint gum might invoke the instant recall of details of a long-forgotten date.

It is known that microscopic lesions found in the brain of a person with Alzheimer’s disease first appear in that part of the brain associated with the sense of smell. Research toward linking the decline in smell sensitivity with the signs of early onset of Alzheimer’s has been of interest to scientists for years.

Findings were recently released of a recent five-year scientific study at Rush University Medical Center in Chicago, performed by Robert S. Wilson, PhD, and his colleagues. Five hundred eighty-nine healthy men and women between the ages of 54 and 100 were asked to repeatedly identify a dozen familiar smells: lemon, smoke, pineapple, banana, rose, chocolate, onion, cinnamon, black pepper, gasoline, soap, and paint thinner.

Factors such as age, gender, education, history of smoking or stroke were considered during this study. At the onset and for each remaining year of the study, the participants underwent a clinical evaluation that included a neurological exam, testing of their cognitive function, and a medical history. The findings of this study, though inconclusive, did show that those receiving the lowest scores while trying to correctly identify the smells did show some association with cognitive decline.

It should be noted that there are reasons other than Alzheimer’s for a decreased sense of smell. Head injury, viral infection, a deviated septum and polyps are all possible reasons why a person’s sense of smell might become compromised. Still there is reason to continue pursuing the possibility of a relationship between the loss of smell and early detection of Alzheimer’s and Parkinson’s. After all, testing for changes in a person’s capacity for smell could be easily and cost-effectively administered as part of an annual physical exam.

Just this April (’07), researchers at the University of Cincinnati announced the development of a new medical device being used to sniff out olfactory disorders. The Sniff Magnitude Test (SMT) is an invention of UC Psychology Professor Robert Frank and UC Cell Biology Professor Emeritus Robert Gesteland and is under further development with the WR Medical Electronics Company in Stillwater, Minnesota.

According to Frank, “For someone with a normal sense of smell, the size of the sniff when detecting an odor is cut in half. For someone who cannot detect odor, the size of the sniff for just air and the size of the sniff for an odor are the same.” This is the premise of the test. Frank compares the importance of early detection of smell loss to that of “the canary in the mineshaft.” In other words, loss of smell could be an early indicator of damage occurring within the brain.

Studies about the relationship of smell to memory are not only being studied with regard to health. Using our sense of smell in the context of advertising by aroma has garnered much interest. Currently, USA Today and the Wall Street Journal are ready to offer “scratch and sniff” newspaper ads. Several California gas stations have begun testing technology that wafts a pleasant coffee aroma at the pump in order to entice customers in for a tasty cup of Joe. Wal-Mart is rolling out experimental DVDs with “smell-o-vision” scent wafers that electronically release certain odors at precise times during a movie. Now, that’s an interesting concept.

Interestingly, there have been some set backs to this new advertising interest. In December, bus shelters in San Francisco were equipped with chocolate chip cookie-fragranced strips for a “Got Milk?” campaign. The strips had to be removed days later because some commuters complained they were triggering allergic reactions.

That setback did not end the interest in scent marketing. It just taught the industry a lesson to avoid enclosed areas. It is estimated that over $500 million will be spent on this type of marketing by 2016. Kind of suspect the smell of money will be making a lot more scents in the future.