Looking at a photograph of yourself, you may feel that you look a little different today. Could that judgment depend not only on the facial image but also on an odor smelled moments earlier?
In 2026, Seongwon Yoon and colleagues presented odors before participants viewed photographs of their own faces, examining ratings of preference and attractiveness alongside the brain’s electrical activity. The study extended research on odor–vision relationships, previously studied in evaluations of other people’s faces, to the process of evaluating one’s own face.
- Viewing the same self-photograph under three odor conditions
- Self-face ratings fell under the unpleasant-odor condition
- EEG responses also differed within a second of seeing the face
- Could an odor-induced emotional state enter self-evaluation?
- Pleasantness and unpleasantness cannot explain everything
- Summary
- References
Viewing the same self-photograph under three odor conditions
Thirty-nine people participated. Eight were excluded for reasons including incomplete questionnaires and olfactory-function problems, leaving 31 in the main rating analyses: 14 women and 17 men, with a mean age of 20.65 years. The final EEG analysis included 28 people.
The three conditions were lavender, isovaleric acid, and a solvent without added fragrance. Isovaleric acid was used as an unpleasant odor reminiscent of sweat. Rather than relying on lavender’s general image as a ‘pleasant fragrance’, the experiment treated it as a neutral odor.
Lavender was diluted to 0.05% and isovaleric acid to 0.01% in mineral oil, and delivered through a device in time with breathing. The control called ‘Air’ in the original paper was also defined in the Methods as mineral-oil solvent alone. The results compare these three conditions, not the effects of every fragrance encountered in daily life.
Participants were photographed with neutral expressions; the images were cropped into oval outlines and processed to standardize brightness. After an odor was presented for one breath, the same photograph of the participant’s face appeared for 0.5 seconds. Participants used nine-point scales to rate odor intensity and pleasantness, how much they liked their own face, and how attractive they found it.
Self-face ratings fell under the unpleasant-odor condition
Isovaleric acid was rated as more unpleasant than both lavender and the solvent control. Both lavender and isovaleric acid were perceived as stronger than the control, but the difference in intensity between the two odors was not significant under the study’s statistical criterion.
Preference and attractiveness ratings for participants’ own faces were lower with isovaleric acid than with both lavender and the solvent control. Neither facial rating differed significantly between lavender and the solvent control.
This does not show that facial shape or physical appearance changed. Ratings of the same photograph changed with odor condition. Nor did the experiment find evidence that this lavender made people find their faces more attractive than in the no-added-scent condition.
EEG responses also differed within a second of seeing the face
The research team averaged repeated EEG recordings aligned to the instant the photograph appeared. Electrical responses associated with a particular event are called event-related potentials, or ERPs. This method allows researchers to examine, at fine temporal resolution, when responses change after an image is seen.
The analysis divided the period from 0.05 to 1 second after face onset into six time windows. Odor conditions differed in the magnitude of electrical responses and the timing of peaks and troughs at several scalp locations. The result was not simply a uniform increase or decrease in activity across the entire brain.
The authors focused particularly on 0.3–0.6 seconds after the image appeared. In this window, the amplitude of the positive response at CP4, a right-sided scalp recording site, showed weak positive correlations with self-face preference and attractiveness ratings.
This analysis examined whether EEG values and facial evaluations tended to vary together. It did not establish that the response caused ratings to rise or fall, or that EEG could accurately reveal an individual’s self-evaluation.
Could an odor-induced emotional state enter self-evaluation?
The authors discuss the possibility that odor influences not only relatively early processing of a face but also subsequent emotional evaluation. The relationship between responses at 0.3–0.6 seconds and facial ratings offers a clue to the idea that odor-induced emotional states contribute to self-evaluation.
Drawing on earlier research, they also suggest that frontal brain regions may link odor and facial information with evaluations of pleasantness. This study measured electrical activity at the scalp, however. It did not directly establish the functions of individual brain regions or the pathway from odor to self-evaluation.
Pleasantness and unpleasantness cannot explain everything
An important limitation is that odor-induced arousal was not measured directly. Here, arousal refers to aspects such as how strongly stimulation activates the nervous system or attracts attention. It is a separate dimension from pleasantness and unpleasantness.
The EEG changes under isovaleric acid cannot be separated into effects of unpleasantness, stimulus-induced arousal, or their combination. A nonsignificant difference in perceived intensity also does not guarantee equal arousal.
Individuals differed in how pleasant they found lavender, and many rated it as pleasant; across the group, however, it did not differ significantly from the solvent control. The authors call for future studies using clearly pleasant and unpleasant odors while also measuring arousal to distinguish the two influences.
The task also involved evaluating one’s own face, without a direct comparison with other people’s faces. Whether the odor effect is specific to self-faces or applies more broadly to faces or judgments in the situation remains to be tested. The predominantly young-adult sample is another consideration.
The study received basic-research funding through the National Research Foundation of Korea from the Korean Ministry of Education and Ministry of Science and ICT. The authors declared no competing interests.
Summary
After smelling unpleasant isovaleric acid, participants rated the same photographs of their own faces lower in preference and attractiveness, and EEG responses after face presentation also differed by condition. The authors suggest that self-evaluation depends not only on visual information but may also be influenced by emotional states created by odors.
Surrounding odors might play a small part in self-impressions even during everyday activities such as getting ready. However, this study did not demonstrate that wearing perfume builds confidence or increases attractiveness. Separating pleasantness from arousal and including comparisons with other people’s faces could clarify how odor enters self-evaluation.
References
Yoon, S., Moon, S., Kim, K., Bae, J., Lee, J., & Moon, C. (2026). Odors modulate self face perception and frontal ERP responses. Scientific Reports, 16, 5082. DOI: 10.1038/s41598-026-35683-3. Full original article. The original article is licensed under CC BY-NC-ND 4.0.
