The effect of smell on learning and memory was investigated in an experiment that used three different ambient odors (osmanthus, peppermint, and pine).
Osmanthus was used to see whether there was a difference in performance depending on whether the smell was novel or familiar. Peppermint and pine were used to see whether the appropriateness or inappropriateness of the smell made a difference to memory.
In the experiment, subjects were individually shown into a room in which the odor was present. Their attention was called to the smell, and to ensure their attention to the smell, they were given a questionnaire to fill out about the room environment. They were left alone in the room for ten minutes to promote encoding of contextual cues.
The experimenter then read out a list of 20 common nouns, pausing after each one for the subject to describe an event that the word reminded them of. Memory for the words was tested 48 hours later.
It was found that word recall was best when the novel odor (osmanthus) was present during learning and again at testing. Among the familiar odors, recall was better if the smell was contextually inappropriate (peppermint). The improvement in recall only occurs when the odor is present at both encoding (learning) and retrieval (testing). Clearly, smell is a good contextual cue.
- Smell can aid memory if the same smell is present during the original experience and when you are trying to remember.
- It works best if the smell is unfamiliar.
- If the smell is familiar, it is better if it is unusual in the context.
Herz, R.S. (1997). The effects of cue distinctiveness on odor-based context dependent memory. Memory and Cognition, 25, 375-380.