The brain combines information from our senses to make sense of our surroundings. This sensory integration leads to associations like warmer temperatures with warmer colors, lower sounds with lower positions, and colors with specific flavors, like oranges. A study in Frontiers in Psychology demonstrates that these crossmodal associations involving smell can impact our perception of colors.
Smell can influence how people see colors
In the study conducted by Ward and colleagues, they investigated odor-color associations in 24 adult participants aged 20 to 57. The participants were in a sensory-neutral environment, not using fragrances, and had normal sense of smell and color vision.
In an isolation room, all existing odors were removed using an air purifier for 4 minutes. Subsequently, one of six randomly selected odors (caramel, cherry, lemon, peppermint, coffee, or odorless water for control) was introduced into the room via an ultrasonic diffuser for 5 minutes.
Ward explained that in a past study they demonstrated that the caramel scent frequently establishes a crossmodal link with yellow and dark brown. Similarly, coffee is often linked with red and dark brown, cherry with shades of pink, purple and red, peppermint with hues of green and blue, and lemon with various shades of pink, yellow, and green.
Participants were asked to adjust color sliders on a screen to turn a randomly colored square into neutral gray. They repeated this process for all colors five times.
Certain colors lead to different perception of gray colors
The study found that participants tended to adjust sliders incorrectly when exposed to certain smells, leading to a distortion in their perception of gray colors. For instance, the smell of coffee made them perceive gray as more red-brown, and the smell of caramel made them see gray as bluer than it actually was. This indicates a consistent impact of smell on color perception.
In the study, participants’ color choices were mostly in line with expected crossmodal associations for four out of five scents, including lemon, caramel, cherry, and coffee. However, an exception occurred when the smell of peppermint was introduced, leading to a different color choice.
