They also sat in front of a screen filled with a random color, whilst an ultrasonic diffuser pumped one of six odors into the room – caramel, cherry, coffee, lemon, peppermint, or water as a control – for five minutes. Using two sliders, participants were then asked to manually adjust the color on the screen to what they perceived to be true neutral gray.

The study found that people had a weak but significant tendency to shift the color too far away from neutral gray, in different but predictable ways depending on the scent – except for peppermint. The smell of coffee made participants perceive gray as a more red-brown color, whilst caramel led to more of a yellow-brown. To be expected given their respective dullness, odorless water corresponded to true neutral gray.

– Read more in Our Sense Of Smell Changes How We See Color at IFLScience.

Different people can have varying perceptions of the same scents and odors, for instance perceiving the same perfume as "fruity" or "musky." Studies have suggested that the ways in which the same odors are mapped in the brain of different individuals are highly flexible, particularly compared to visual stimuli, which are typically represented similarly.

—  Read more in Study sheds light on the neural underpinning of subjective odor perceptions at Medical Xpress.

When a fragrance wafted through the bedrooms of older adults for two hours every night for six months, memories skyrocketed. Participants in this study by University of California, Irvine neuroscientists reaped a 226% increase in cognitive capacity compared to the control group. The researchers say the finding transforms the long-known tie between smell and memory into an easy, non-invasive technique for strengthening memory and potentially deterring dementia.

— Read more in Sweet smell of success: Simple fragrance method produces major memory boost at ScienceDaily.