Can we smell colour? What do yellow, green, purple, or brown smell like? For my dissertation I was keen to explore something that we may not notice or think about in our daily lives: how smell and vision interact, more specifically how colour and smell perception are linked.

The set-up of the experiment

In my early teenage years, like most of the population my age, I spent a lot of time shopping in Hollister, and one of the main things I remember from that experience was the smell of the store. Hollister is not alone in this; many brands use scents to create an association with their brand. For example, Victoria’s Secret spray their perfumes into the bag of everything they sell. Another thing that brands also rely heavily on to advertise and market their products is colour. Research (e.g. Labrecque, Patrick, & Milne, 2013) has suggested that the impact of an advert is affected by how the elements, such as the product and the colour-scheme, fit together. The same applies to colour and smell – products that have a lemon or citrus smell tend to have bright yellow packaging, coffee or hot chocolate packaging tend to use brown or black packaging, to name but a few.

When searching for literature around the topic, I discovered that a majority of research has shown participants tend to fixate for longer and faster on objects and colours that are congruent with smells that are presented to them. However, I also found that in one study (Seigneuric, Durand, Jiang, Baudouin, & Schaal, 2010) participants spent shorter periods of time observing stimuli that were associated with the smell they were presented with. However, the researchers claim that this may be because it took the participants less time to identify the relevant stimuli. I was interested to see whether my results would follow the pattern of the former, or the latter.  

To test this, with the help of my supervisor Dr Britta Osthaus, and Dr Philip Ulrich, I set up an experiment using an eye tracker, an image that contained a variety of coloured sections, and four different scents: lemon, coffee, lavender, and peppermint. Each participant was asked to smell a scent for 15 seconds, whilst looking at the image that contained a range of colours. Some of the colours were associated with the smells, i.e. yellow for lemon, brown for coffee, purple for lavender, and green for peppermint.

Conducting research at the start of a global pandemic meant that I was only able to secure results from eight participants. Nevertheless the data generated some interesting results. Heatmaps from the eye tracker and the mean observation times for the relevant areas on the stimuli showed that for the lemon, lavender, and peppermint conditions, participants spent longer observing the relevant coloured areas on the stimulus. But it was only in the peppermint condition that participants fixated first on the corresponding area of interest.

Statistical tests suggested that there were significant differences between the observation times for the lemon, coffee, and lavender conditions. This could imply that there may be some truth to the suggestion there is an interaction between vision and smell, and that individuals will observe both corresponding and unrelated areas of stimuli for different periods of time. The same could not be said for the first fixation times. This suggests that it may not be possible to assume that some areas of the stimuli catch the eye of the participants faster than any of the others. My results did support a majority of the existing research, but due to the Covid-19 sample size it is not possible to generalise these findings. There is still a lot of interesting research to be done in this area where cognitive psychology meets consumer psychology.

By Ella Francis

References

Labrecque, L.I., Patrick, V.M., Milne, G.R. (2013). The Marketers’ Prismatic Palette: A Review of Color Research and Future Directions. Psychology and Marketing, 30(2), 187-202. doi: 10.1002/mar.20597

Seigneuric, A., Durand, K., Jiang, T., Baudouin, J., & Schaal, B. (2010). The nose tells it to the eyes: Crossmodal associations between olfaction and vision. Perception, 39(11), 1541-1554. doi: 10.1068/p6740