Scientists from Liverpool John Morris University in the United Kingdom have found a relationship between the sense of smell and how we perceive colors.
The study, published in the journal Frontiers in Psychology, clearly explains how the human body deals with our five senses.
Our five senses bombard us with environmental input 24/7. One way our brain makes sense of this abundance of information is by combining information from two or more senses, such as smells, softness of texture, pitch, color, and musical dimensions. This sensory integration also makes us associate higher temperatures with warmer colors, and colors with the flavor of certain foods, for example, the taste of orange with the color of the same name.
During the experiments, lead author Dr. Ryan Ward studied the “strength of the association between smell and color” in 24 adults between the ages of 20 and 57 years. Participants were seated in front of a screen inside an air-filtered room “free of unwanted sensory stimuli” for the duration of the experiments. They did not use deodorant or perfume, and none of them reported color blindness or a poor sense of smell.
One of six odors (randomly selected from caramel, cherry, coffee, lemon, and mint, plus unscented water as a control) was then diffused into the chamber using an ultrasonic diffuser for five minutes.
Ward noted that a previous study found that the smell of caramel "forms a cross-modal association with dark brown and yellow."
Coffee did the same with red and dark brown, cherry scents with pink, red and purple, mint with green and blue, and lemon with yellow, green and pink.
Participants in the recent study were shown a square filled with a random color on a screen and were given two sliders to change the shade to neutral gray five times for each odor.
He found that they had a “weak but significant tendency” to adjust one or both sliders away from gray.
For example, in the case of coffee, gray was mistakenly perceived as reddish-brown. For caramel, the color was falsely enriched with blue.
The researchers found that smell distorts color perception in a predictable way. Mint was an exception.
“These results show that gray color perception leans toward the expected cross-modal correspondences for four out of five odors, namely lemon, caramel, cherry, and coffee,” Ward said. “This overcompensation suggests that the role of cross-modal associations in processing sensory input is strong enough to influence how we perceive "For information from the different senses, here between smells and colors."
As research progresses, Ward insists that scientists need to look to the rainbow for answers.
He added: "We need to know the extent to which odors influence color perception. For example, whether the effect shown here still exists for less common odors, or even for odors that are encountered for the first time."
Study: Weedkillers impair brain function in adolescents
Scientists at the University of California, San Diego, have discovered that exposure to harmful weed pesticides used in agriculture leads to impaired brain function in adolescents.
Environmental Health Perspectives notes that researchers collected urine samples from 519 teenagers aged 11-17 years living in Ecuador. The researchers also evaluated indicators of attention, control, memory, learning, language, and visual-spatial and social perception.
It became clear to the researchers that two types of harmful weedkillers, glyphosate and 2,4-dichlorophenoxyacetic acid (2,4D), are present in the bodies of most of the study participants, as the first substance was detected in 98 percent of the samples and the second in 66 percent of the samples.
According to researchers, high levels of 2,4D in urine have been associated with poor attention, control, memory, learning, and language. Increased glyphosate concentrations were associated with poorer social perceptions.
Weed killers are the most widespread in the world. Glyphosate is used in many crops, including corn and soybeans. 2,4D is a broadleaf herbicide used on lawns, water bodies and crops. After the emergence of crops resistant to these pesticides in 1996 and 2014, there was a significant increase in the use of glyphosate and 2,4D.