Our sense of smell changes how we see color

A group of scientists have uncovered the way we see color is impacted by our sense of smell.

A team from Liverpool John Moores University, the University of Liverpool and Cambridge University investigated how people's perception of color changes when presented with different odours.

If you smell hot chocolate, you're probably going to think of the color brown and if you smell a banana, the color yellow - but does smelling those scents actually influence how you actually see color in front of you?

Well, a group of scientists have put it to the test just how far smell can influence people's perception of color.

The study involved 24 people (11 men and 13 women) between the ages of 20 and 57, sat in individual blacked out rooms with the lights turned off, in front of a screen.

The participants were banned from wearing perfume or deodorant to limit any conflicting smells.

An IQAir HealthPro 250 Air Purifier was also used to make extra sure no additional odors in the room interfered with the experiment.

Frontiers/ Liverpool John Moores University

Then, along with odorless water which was used as a control, smells were introduced into the room via an ultrasonic infuser one after another.

The scents included caramel, cherry, coffee, lemon and peppermint. All quite pleasant smells, thankfully.

The participants were given a random color and asked to use two sliders - 'one for yellow to blue and another for green to red' - to change the color to a neutral gray for each different smell.

The scientists wanted to know if the various scents would distort the participants' perception of what a neutral gray was.

Well, it turns out all of the scents apart from peppermint seemed to alter people's idea of neutral gray, but not always in the ways you'd expect.

Pexels/ Porapak Apichodilok

While coffee made people perceive neutral gray as more red-brown, for some reason those who smelled caramel thought neutral gray was bluer than it actually was.

In general, the researchers found that the smells shifted the participants' perception of neutral gray towards 'warmer colors'.

Lead author Dr Ryan Ward said further studies are needed to ascertain whether smell influences perception of colors when it's the first time, or first few times, someone has encountered a specific smell.

So there you have it, your morning cup of coffee might be making the world seem that little bit more red-brown than it actually is.