In 2007 I received a really cool Christmas present that I still haven’t used. It’s a kit to help identify the various components of the aroma in a glass of wine. I haven’t used it because I wanted to wait for the right occasion — say, a party with some of my wine-loving friends. But I’ve also been secretly skeptical whether it would really help. The kit has tiny vials that are supposed to represent individual aromas: “oak,” “hazelnut,” “coffee,” “cherry,” and so on. What does identifying an aroma have to do with deciding whether you like a glass of wine?
As it turns out, more than you might think. Richard Stevenson, Trevor Case, and Mehmet Mahmut took a look at the history of research into aromas and found that in nearly every case, people have had great difficulty identifying and imagining them. If I ask you to visualize a physical object that you have seen before: a car, a giraffe, and so on, you would probably have little difficulty. But if I ask you to imagine a smell, even one you have recently experienced (perhaps you opened one of the little vials in my kit), you would find it much harder to do.
Another problem with odor detection is identification. Most people can readily identify common items when they can see them: oranges, nuts, cats. But when asked to identify an odor when there is no other information about the object, they are much less accurate.
Stevenson’s team says that one of the primary reasons we have trouble identifying odors is that we usually don’t have names for them. They trained 12 volunteers to recognize 15 different odors by having them sniff unlabeled vials of scented liquid. Other volunteers were exposed to the odors the same amount of time but not given their names, or trained on the names of the odors without being allowed to smell them. One week later, everyone was exposed to all the odors one more time, and given each odor’s name (baby powder, lemon, shoe polish, oregano, etc.). Then they were asked to identify the odors. A fourth group, which didn’t have any training, was tested in the same way. Here are the results:
The people who were trained on the names of the odors were significantly better at identifying them, compared to everyone else in the study. Being trained on the names of the odors in advance did help a little in terms of accuracy, but it didn’t help at all when asked to imagine the odors. All the participants were asked to imagine each odor and then report on how well they could imagine the odors. Here are the results for the easiest odors (Vicks Vap-o-Rub, Baby Powder, Lemon):
Those who learned the names of each odor rated them as being significantly easier to imagine and significantly more vivid. The images were formed significantly faster as well. Being exposed to just the odors or the names didn’t help people imagine the odors more vividly or faster.
So, returning to my wine-tasting example, this study suggests that being able to identify specific aromas with a label like “cinnamon” or “smoke” may improve my ability to imagine what a particular wine smells like. Later, when I’m in the store trying to decide what wine to buy, that memory could help me make a better purchase. I guess I should start calling up my friends to arrange a wine-smelling party!
Update: Over at BPS Research Digest, Christian has nearly simultaneously posted about describing wine and its impact on memory.
Stevenson, R.J., Case, T.I., Mahmut, M. (2007). Difficulty in evoking odor images: The role of odor naming Memory & Cognition, 35 (3), 578-589