Seeing Scents: The Cross-Modal Impact of Visual Cues on Fragrance Mixture Perception

This work forms part of a broader investigation into how colour influences odour perception. In each study, cis-3-hexenol is paired with a different odour molecule, using both equal and varying intensity combinations to examine the impact of colour cues on olfactory experience.

Crossmodal interactions play a central role in the cosmetic industry, enabling formulators and brand leaders to craft multisensory experiences that align with consumer expectations. Among these, vision and olfaction are tightly linked—colour cues can bias how we perceive and identify odours, often before the first sniff.

Stable colour–odour associations (e.g. yellow–lemon) are frequently leveraged in packaging and product design to convey freshness, warmth, or intensity. Behavioural and neuroimaging research shows that congruent visual cues not only accelerate odour recognition but also co-activate olfactory brain regions.

However, interpreting odour–colour links in blended fragrances presents challenges. Odours may be processed elementally (as distinct parts) or configurally (as a new whole), and volatile notes like cis-3-hexenol often dominate or mask heavier ones like γ-nonalactone during early sniffing.

Additional complexity arises from individual differences—factors like age, culture, genetics, and experience influence how people associate smells with colours. Even minor structural variations in molecules (e.g. chirality, functional groups) can alter odour quality, complicating generalisation.

While most studies focus on single aroma compounds, few explore how colour modulates perception in binary mixtures. This study addresses that gap, using cis-3-hexenol (green/grassy) and γ-nonalactone (fruity/sweet) to explore crossmodal effects in blended odours.