The findings, by researchers from the Monell Chemical Senses Center in US, suggest that the use of scented products such as perfumes may, to some extent, alter how people perceive one another. (Agencies)
"Odour pleasantness and facial attractiveness integrate into one joint emotional evaluation," said lead author Janina Seubert, a cognitive neuroscientist who was a postdoctoral fellow at Monell at the time the research was conducted.
"This may indicate a common site of neural processing in the brain," Seubert said.
Perfumes and scented products have been used for centuries as a way to enhance overall personal appearance. Previous studies had shown perception of facial attractiveness could be influenced when using unpleasant versus pleasant odours.
However, it was not known whether odours influence the actual visual perception of facial features or alternatively, how faces are emotionally evaluated by the brain.
The current study design centred on the principle that judging attractiveness and age involve two distinct perceptual processing methods: attractiveness is regarded as an emotional process while judgements of age are believed to be cognitive, or rationally-based.
In the study, published in open access journal PLOS ONE, 18 young adults, two thirds of whom were female, were asked to rate the attractiveness and age of eight female faces, presented as photographs. The images varied in terms of natural ageing features.
While evaluating the images, one of five odours was simultaneously released. These were a blend of fish oil (unpleasant) and rose oil (pleasant) that ranged from predominantly fish oil to predominantly rose oil.
The subjects were asked to rate the age of the face in the photograph, the attractiveness of the face and the pleasantness of the odour.
Across the range of odours, odour pleasantness directly influenced ratings of facial attractiveness. This suggests that olfactory and visual cues independently influence judgements of facial attractiveness.
With regard to the cognitive task of age evaluation, visual age cues (more wrinkles and blemishes) were linked to older age perception.
However, odour pleasantness had a mixed effect. Visual age cues strongly influenced age perception during pleasant odour stimulation, making older faces look older and younger faces look younger.
This effect was weakened in the presence of unpleasant odours, so that younger and older faces were perceived to be more similar in age.
The findings, by researchers from the Monell Chemical Senses Center in US, suggest that the use of scented products such as perfumes may, to some extent, alter how people perceive one another.