Sense-triggered memory: why smelling your ex-boyfriend’s old sweatshirt makes you want to cry
Have you ever smelled a certain cologne and felt your heart drop because it was the one your ex-boyfriend wore? Or have you caught a whiff of your mom’s apple pie and affectionately remembered devouring a slice with your brother? Maybe you’ve smelled a certain brand of cigar and remembered how happy you were bouncing on your grandfather’s knee as a child. Certain sensory cues can be very powerful triggers for emotional memories. While many people think of sounds such as music as being strong memory cues, smells actually produce the most emotional and evocative memories.
A recent study by Rachel S. Herz of Brown University analyzed memories triggered by different sensory cues: just reading the word for the item, smelling the item, hearing the item, or seeing the item. First, participants were asked to think of a personal memory associated with a certain item- popcorn, fresh-cut-grass, or campfire. Participants were only prompted by the word of the item, not the physical item itself. Participants provided a brief verbal description of the memory, and were also asked to rate it on 4 scales: how emotional it was, how vivid it was, how evocative it was (how much they were brought back to that place and time), and how specific it was.
Immediately after, participants were presented with the same item in its various sensory forms (visual, olfactory, and auditory). The visual forms were silent videos of a bowl of popcorn, a lawnmower cutting grass, or a bright campfire at night. The olfactory forms were oil-based beads that gave off realistic, authentic smells of the items. The auditory forms were sound clips of popcorn popping, a lawn mower starting and cutting grass, or a slow crackling fire. The participants were again asked for a description of the memory after each cue, and rated it on the same 4 scales. Therefore, each participant evaluated each memory four times, first recalled verbally, and then recalled visually, olfactorily, and auditorily. The verbal cue was always presented first, but the order of the three sensory cues varied to be sure that the order was not affecting recollection- for example, the memories did not get more or less emotional as they were re-told and evaluated.
The results indicated that memories were most emotional when the participants smelled the cue. Participants also felt most brought back to the event by the smell as opposed to the other cues. However, the type of cue did not influence how vivid or specific the memory was.
Additional tests based on age differences found some interesting results. The oldest age group (50–79 years) had the most emotional and vivid memories elicited by fresh-cut-grass, and the youngest age group (7–18 years) had the most vivid memories elicited by campfire. Herz explains that these differences are probably due to the different experiences that these age groups had with fresh-cut-grass and campfires. Older participants had stronger memories associated with cutting grass than younger age groups because they have had more experience with it. Also, 40–60 years ago the likelihood of an American family having a yard was greater, and the family ritual of cutting grass was more prevalent. The youngest age group’s strong reactions to campfire were likely due to recent experiences at summer camp.
Geographic location also affected memory. Participants from the city had the most vivid memories of popcorn, and people from rural/country areas had the most vivid memories of fresh-cut grass. Again, this is probably due to having more experience with popcorn or fresh-cut grass based on location.
To summarize, the study showed that memories elicited by smells were more emotional and evocative than memories cued by the visual, verbal, or auditory version of the smell. So the next time you smell your roommate’s sweaty soccer cleats and remember the thrill you felt when you scored a game winning-goal, maybe instead of wrinkling your nose, you will stop to appreciate the power of smells.
Herz, Rachel S. (2004) A naturalistic analysis of autobiographical memories triggered by olfactory visual and auditory stimuli. Chemical Senses, 29, 217–224.
This is a very interesting study as I have experienced the phenomena of smells eliciting an emotional response many times. In my experience, sometimes I am encountered with a smell that elicits strong emotions and a sense of familiarity, but have a difficult time pinpointing the memory for which the smell is linked- somewhat like the tip of the tongue phenomena (or rather tip of the nose). I wonder if there are any studies exploring the emotion evoking nature of smells without conscious understanding of the memory the smell comes from.
This is so interesting! What is funny is that just reading this and thinking of the scenarios you listed, I was able to recall certain memories. I was just wondering if participants had labeled the smells when they were recalling memories. I know with certain smells, I know that there is a memory for it, but I don’t know the exact scent (my grandmother’s perfume, but I don’t know what brand it is but I know it is the same one when I smell it). Also, was there a difference in gender between recollection based on smells? Just out of curiosity, did they give any information regarding how certain smells are meant for certain memories, like I can remember the smell of my grandmother’s perfume, but the smell of certain foods she cooked do not elicit that same connection for me. I know that is most likely not in the article, but I thought that is interesting!
I really enjoyed reading about the effects that smells have on our memory. It was somewhat surprising to me that smells elicit the most vivid emotional memories as compared to sight and sound. I certainly have had the experience of smelling something familiar and having a memory come back to me. I wonder what it is about smells that triggers an emotional response more so than sight and sound? I read an article on “HowStuffWorks.com” in which this topic was discussed. Researchers noted that the olfactory bulb is a part of the brain’s limbic system, which is often referred to as the “emotional brain.” The limbic system is associated with feeling and memory, explaining the connection between emotional memories and smell. It was also discussed in the article that conditioned responses play a critical role in our tendency to associate smells with a particular memory. The most interesting finding to me was that we begin making these associations prior to birth. It was found that infants who were exposed to alcohol, cigarette smoke or garlic in the womb show a preference for the smells! I think this is a very cool topic, and holds many implications regarding the significance of memory. I wonder how, or if results would differ for individuals with different memory disorders.
Here is the link to the article. I thought it was pretty cool:
http://science.howstuffworks.com/life/human-biology/smell3.htm
I find this extremely interesting as I get this phenomena all the time! There was actually a certain smell that I associated with Colby that I could never pinpoint. It turns out it’s the mulch that they’ve been putting out (which most people find disgusting.. whoops, I guess?). I also found Katherine’s comment very interesting because I too have experienced strong nostalgic feelings upon smelling something without being able to recall the specific memory, and it drives me up the wall. I would love to learn more about scent-triggered memories.
Smell and taste are very connected senses; food tastes less distinctive if you do not have a sense of smell. So perhaps the link between scent and memory is why soul food is so comforting. I don’t crave my mom’s spicy pasta or my dad’s specialty barbecue ribs solely because they taste good, but also because they remind me of all the memories I have at home. Sure, those barbecue ribs are delicious, but they also remind me of every 4th of July spent with family and friends, sitting around the table on the back patio in the warm summer air. So in the same way that a scent can be a throwback, a taste can too.
I think this phenomenon is logical considering olfaction is the most primitive of senses, chronologically speaking. Because of its primitive origin in evolutionary history, as well as neuroanatomical position (lower portion of brain), I wonder about other studies conducted with other animals. I would assume because of olfaction’s evolutionary origin, that all mammals would have a similar response: i.e. smell would evoke a stronger memory. Nontheless, this was a very interesting post.
You mentioned that memories triggered by smell are reported to be more emotional. I wonder if the accuracy of these memories is a enhanced or decreased by associating them with smells. To give a guess, I might say that these smells could produce flash-bulb type memories. As these memories are especially vulnerable to many sins of memory, I might suggest that these are not the most accurate. Perhaps one memory triggered by smell is a combination of all the similar experiences related to that one scent.