Can Smell Training Change What Children Notice?

Some children readily notice odors from food and their surroundings, while others pay little attention to them. Could daily smell training change not just their ability to identify odors correctly but also their tendency to notice scents in everyday life?

In 2025, Anna Oleszkiewicz and colleagues investigated 12 weeks of olfactory training in children in Poland. Their main aim was to determine whether training changed awareness of odors and the importance children attached to them in daily life. Odor identification and the ability to retrieve words were measured separately.

The same training with scented and odorless pens

The study began with 130 children. After excluding 25 who did not attend the second assessment and four in the scented group whose training compliance was below 25%, the final analysis included 101 children aged 6–9. There were 57 in the scented group and 44 in the odorless comparison group.

After the initial assessment, children were randomly assigned to two groups. The scented group used pen-shaped dispensers with rose, eucalyptus, lemon, and clove odors. The comparison group received dispensers of the same shape without fragrances.

Both groups were instructed to smell each pen for about 30 seconds, twice a day, for 12 weeks. Both also used the same system of placing a sticker on a poster after each session, with help from parents or other adults. Rather than comparing training with doing nothing, the design matched the act of trying to smell and the daily focus on that behavior across the two groups.

This comparison aimed to separate, as far as possible, the effects of a daily smelling routine itself from those of actually receiving odor stimulation.

Measuring awareness separately from correct identification

Odor awareness and significance were measured using 10 questions answered by the children themselves. These asked how they perceived odors in food, the surrounding environment, and social interactions, producing a total score of 0–20. This was not a direct test of how faint an odor the nose could detect.

Separately, children completed a test identifying 12 odors by choosing names from four alternatives. In the verbal task, they listed as many words as possible beginning with a specified letter within one minute.

The odorless group’s average age was about 7.9 years, compared with about 7.4 in the scented group, so age was taken into account in the analysis.

Scores rose in the scented group, but a difference in improvement was unclear

Mean awareness-and-significance scores changed from 9.07 to 9.65 in the scented group and from 10.16 to 10.70 in the odorless group. Looking simply at the averages, both increased slightly.

When each group was examined separately in an analysis accounting for age, the pre–post difference was statistically clear in the scented group but not in the odorless group. However, the key test of whether the pattern of change differed between the two groups did not show a clear difference.

A significant change in one group alone does not necessarily demonstrate a greater effect than in the other. These findings do not establish that adding actual odors increased children’s awareness more than odorless training did.

The odor-identification and word-generation tests likewise showed no clear differences between the scented and odorless groups in changes from before to after training. The results do not show that interest in scents, odor-identification ability, and word-generation ability all improved together.

What about children who initially pay less attention to odors?

The authors consider the small increase in the scented group as suggesting that smell training might affect conscious awareness of odors. Because the scented group had lower awareness scores at the outset, they particularly propose closer investigation of children who initially pay less attention to odors.

However, the study did not demonstrate that training works for children with low starting scores. The groups differed at baseline, and their changes did not clearly differ, so this interpretation remains a hypothesis for future testing.

The researchers suggest that, if an effect on awareness is confirmed, training might be incorporated into everyday school activities. The relationship between attention to odors and food choices was also part of the study’s motivation. However, the experiment did not measure improvements in actual eating habits or health, and benefits for education or diet have not been demonstrated.

Questions remain about measurement and adherence

Odor-identification scores already averaged about 10 out of 12 at the start. The authors suggest that a test designed to detect olfactory problems may have difficulty capturing small improvements in children who already perform well. They call for more demanding measures, such as naming odors without response options.

The awareness questionnaire was also adapted for children, and response consistency was limited. Twenty-five children did not attend the second assessment, and exclusion for very low training adherence was applied only to the scented group. The analysis also did not separate the effects of attending the same school or class.

The findings therefore need to be reassessed in more children, taking age, school environment, and baseline status into account. Comparing smell training with lessons or workshops about odors is another next step identified by the authors.

Summary

After 12 weeks of training, awareness scores rose slightly in the scented group, but a larger change than in the odorless group was not confirmed. Improvements in odor identification and word generation were also unclear.

Nevertheless, it is meaningful for research on olfactory development to measure not just test performance but also awareness of odors in daily life. The authors want to investigate interventions targeting this aspect, especially in children with low awareness or olfactory difficulties. To make such approaches useful in schools, the effects of actual odor stimulation need to be established more clearly.

References

Oleszkiewicz, A., Rokosz, M., Gargula, L., Marek, D., Nawrocka, P., Reichert, A., Zienkiewicz, K., Zyzelewicz, B., & Sorokowska, A. (2025). Olfactory training and metacognitive aspects of olfaction in children aged 6–9 years: a preliminary study. Psychological Research, 89, 100. DOI: 10.1007/s00426-025-02127-y / Full original article.

Original article license: CC BY 4.0. © The Author(s) 2025.