Is Text More Memorable When Accompanied by Scent?

When you read a poem describing the scent of flowers, would smelling those flowers too make its content easier to remember? In 2024, Wenhao Li and colleagues tested learning accompanied by odors matched to poems with 87 fourth-grade pupils in China.

The researchers wanted to know more than whether scent creates a pleasant atmosphere. They examined whether words remained in memory several days later, whether pupils found it easier to construct the poems’ scenes and emotions in their minds, and whether adding more information to process at once increased their workload.

Synchronizing odors with the text

The participants were 87 pupils at one Chinese elementary school, with a mean age of approximately 9.4 years. They were randomly assigned to an odor group of 44 or a text-only group of 43. The materials were three short poems not yet covered in class: one describing mint in bloom, one praising osmanthus, and one depicting a desolate battlefield.

In the odor group, mint, osmanthus, and ammonia were presented to accompany the respective texts on screen. The researchers chose the last odor to correspond to the tragic scene. This was not an experiment that added only pleasant scents.

A computer controlled a homemade device to release an odor while each poem was being read and let it dissipate before the next poem. Pupils studied each poem for two minutes, with a total learning period of ten minutes including breaks. The text-only group completed the same learning activities. The key was presentation matched to the content, rather than continuously filling the room with a single fragrance.

Measuring immediate memory separately from memory after three days

Immediately after learning, pupils completed a recognition task in which they selected words that had appeared in the poems from a set of candidates. Similar-meaning distractor words were included to test whether they could identify the correct ones. They repeated the recognition task three days later. This was not a test of reciting the poems word for word without help.

In another immediate task, pupils chose one of the three poems, drew the scene they imagined, and added a short explanation. Trained raters assessed whether they remembered elements of the poem, understood its meaning, expressed its emotions, and depicted an overall scene consistent with it. Each dimension was scored from 0 to 3, for a total of 12 points.

The authors used this task to assess schemas: organized mental representations that connect a text’s elements and meanings. It was neither a drawing competition nor a task measuring only memory after three days.

The main recognition difference emerged after three days

The immediate recognition total averaged 16.27 points in the odor group and 17.51 in the text-only group, with no statistically significant difference. There were also no significant immediate differences when the poems were examined separately.

After three days, the odor group averaged 18.11 points and the text-only group 16.40, a significantly higher score in the odor group. However, when each poem was considered separately, a clear difference emerged only for the osmanthus poem; there were no significant differences for the mint or battlefield poems.

This pattern led the authors to suggest that a close connection between text and odor content may matter. The odor accompanying the osmanthus poem directly matched the subject described in its words. Nevertheless, the experiment did not vary only the degree of congruence, so congruence alone cannot be established as the reason for the effect.

Differences in scene understanding and emotional expression

On the immediate task involving a drawing and short explanation, the odor group averaged 5.10 points in total compared with 3.60 in the text-only group, a significant difference. The odor group scored higher for understanding meaning, expressing emotion, and constructing a coherent scene. There was no significant difference in the memory component assessing how many elements of the poem were depicted.

In other words, the results did not uniformly show that odor made pupils remember more of every detail. The authors propose that odors may give abstract words concrete imagery and help pupils construct scenes with emotional content. This is an interpretation of drawing and explanation scores, not a direct observation of representations formed in the brain.

More enjoyable does not necessarily mean no workload

A questionnaire about workload during learning showed no significant difference between the groups. Under these conditions, there was no clear evidence that adding odor increased the burden. This does not demonstrate that any odor can be used for any length of time without adding workload.

Overall learning-experience scores also did not differ significantly, but two items corresponding to finding the activity interesting and enjoyable were higher in the odor group. The authors note that the novelty of the equipment or learning method could also explain this. Whether the same enjoyment and effects persist with continued use requires separate investigation.

Consider the content and purpose before adding scent

The authors propose using odors selectively to match learning content and goals. Design needs to address not only the scent itself, but its relevance to the text, intensity, timing, and removal of lingering odors. The outcomes worth evaluating also depend on whether the aim is more correct answers immediately or better later memory and understanding of a scene.

The study involved fourth graders at a single school, three poems, and a three-day follow-up. The homemade device made precise control of concentration and presentation and removal timing difficult, and pupils’ olfactory ability was checked by self-report. The study did not validate procedures or safety for reproducing these research conditions, which included ammonia, at home or in ordinary lessons.

Summary

In this experiment, adding content-matched odors improved word recognition after three days and performance on an immediate task expressing a scene through a drawing and explanation. Immediate recognition did not improve, however, and the three-day difference appeared mainly for the osmanthus poem.

Rather than a universal extra ingredient for memorizing text quickly, scent may provide a cue linking words, sensations, and scenes. What odor should accompany what content, and when? The study suggests that carefully designing this combination matters for realizing its potential in learning.

References

Li, W., Qian, L., Feng, Q., & Luo, H. (2024). Using olfactory cues in text materials benefits delayed retention and schemata construction. Scientific Reports, 14, 17819. DOI: 10.1038/s41598-024-68885-8 / Full original article.

Original article: © The Author(s) 2024. CC BY-NC-ND 4.0.