A series of experiments with volunteers aged 13 to 25 showed that they were better able to recall images that were associated with unpleasant odors.
Specifically, they had better recall of images 24 hours after seeing them if the images were paired with a bad smell.
The study also found that people who had greater arousal responses (measured by palm perspiration) at the instant when they might be exposed to either a bad smell or clean air while viewing the image — regardless of whether or not they were actually exposed to a smell — had better recall of the images 24 hours later.
This suggests that unpredictability or surprise associated with the outcome leads to better memory, according to the New York University researchers.
“These results demonstrate that bad smells are capable of producing memory enhancements in both adolescents and adults, pointing to new ways to study how we learn from and remember positive and negative experiences,” senior author Catherine Hartley said in a university news release. Hartley is an assistant professor of psychology cognition and perception.
It’s long been known that negative experiences have a significant impact on memory. For example, people who suffer a dog bite may develop a negative memory of the dog, which may expand into a negative association with all dogs, according to the researchers.
The trauma linked with the bite might also make that experience stronger in the memory than other interactions with dogs.
“The generalization and persistence in memory of learned negative associations are core features of anxiety disorders, which often emerge during adolescence,” Hartley said.
The study will be published in the July issue of the journal Learning and Memory.