Nav: Home

Distracted people can be 'smell blind' -- according to new University of Sussex study

June 05, 2018

'Inattentional smell blindness', or inattentional anosmia, has been proven to exist in a study from the University of Sussex. Just as it has previously been found that people can miss visual cues when they are busily engaged in a task, the same is true of smells.

And unlike visual stimuli, which would be noticed once the person stops being busy, the problem with a smell is that there is only a short window before the person becomes habituated to it, and the opportunity to notice it has passed.

Dr Sophie Forster undertook the research with Prof Charles Spence at the University of Oxford.

Dr Forster from the University of Sussex said: "We have discovered that people are less likely to notice a smell if they are busily engaged in a task. Many of us have experienced this: we've been working in a room when a new person has entered and said that the room smells of something such as someone's lunch, but that those already in the room had failed to notice it.

"What's more, we found that because habituation to smells is much stronger than other senses, if we habituate during a period of distraction we might never notice a smell. Previous research has told us that, unique to the sense of smell, there is only a window of approximately 20 minutes before the brain is no longer able to detect it - a phenomenon known as olfactory habituation.

"Our study could have a range of implications. For example, if you are busy focusing on a task you may be less likely to be tempted by food smells. Or if you don't want your friend to guess you are baking them a birthday cake in the other room, you could distract them with a puzzle for about 20 minutes.

"Our test was done with the smell of coffee but the next step for us will be to test 'threat smells' such as smoke and gas. Could it be, for example, that drivers who are concentrating on a busy motorway and perhaps are also engaged in a conversation, might may fail to notice a burning smell which should act as a warning sign? Or perhaps the same is true of engineers who work busily in situations which place them at risk of a gas leak."

In the study the psychologists asked participants to enter a room in which they had previously hidden coffee beans, with the result that it smelled strongly of coffee. In the room the participants performed one of two versions of a visual task, designed to place either high or low demands on attention. After leaving the room participants were asked to describe the room, and then asked follow up questions to determine whether or not they had noticed the smell. Those participants whose attention was occupied by the more demanding task were 42.5% less likely to notice the smell. The participants were typically really surprised when they returned to the room afterwards to discover the strong coffee smell, which they had previously missed.

The second finding - that people may never notice a smell if they have habituated to it - was tested in a follow up experiment in which participants were asked what they could smell while they were still sitting in the room which smelt of coffee. The majority (65%) couldn't detect the coffee because they had habituated while they were doing the task.

The researchers were testing the 'perceptual load hypothesis', which is an idea that people can only perceive sensory information until their capacity is full. It explains the well known 'Did you see the gorilla?' inattentional blindness study, where observers are asked to focus on the number of ball passes between players wearing white, and almost always miss the person in a gorilla suit who walks across the scene, does a little dance in the middle and walks off.

Dr Forster said: "In the case of visual or auditory information, we tend to notice it once we are no longer busy. However, the brain can habituate to smells so strongly that they cannot be detected even when we are specifically asked about smells in the room. If this habituation occurs during the period that people are distracted by a task, the opportunity to detect a smell may be missed. It is thought that the reason that there is a time limit for detecting smells relates to fact that the olfactory system evolved before the other senses, and therefore is more basic and animalistic."

'"What smell?" Temporarily loading visual attention induces a prolonged loss of olfactory awareness' will be published soon in Psychological Science.
-end-


University of Sussex

Related Coffee Articles:

Take a coffee or tea break to protect your liver
According to a new study published in the Journal of Hepatology, researchers found that drinking coffee and herbal tea may protect against liver fibrosis, estimated as the degree of liver stiffness, which is high in extensive scarring of the liver.
The universe in a cup of coffee (video)
Reactions, the ACS YouTube channel that covers the chemistry of everyday life, is joining PBS Digital Studios, a network of original web series from PBS that explore science, arts, culture and more.
Arabica coffee genome sequenced
University of California, Davis, researchers today announce the sequencing of the genome of Coffea arabica, the species responsible for more than 70 percent of global coffee production.
Coffee-ring phenomenon explained in new theory
The formation of a simple coffee stain has been the subject of complex study for decades, though it turns out that there remain some stones still to be turned.
Matchmaking for coffee?
By combining macadamia and coffee crops in a single field, researchers demonstrate a more weather-tolerant, productive, and profitable crop.
The mathematics of coffee extraction: Searching for the ideal brew
Composed of over 1,800 chemical components, coffee is one of the most widely-consumed drinks in the world.
Chill coffee beans for a more flavorsome brew, say scientists
In the lead up to the World Barista Championships, University of Bath scientists say brewing more flavorsome coffee could be as simple as chilling the beans before grinding.
Better coffee through chemistry (video)
It's one of the most popular beverages in the world, and many of us rely on it to stay awake every day.
You can thank diverse yeasts for that coffee and chocolate
Humans have put yeast to work for thousands of years to make bread, beer, and wine.
New insights into the evaporation patterns of coffee stains
Few of us pay attention to the minutiae of coffee stains' deposition patterns.

Related Coffee Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Bias And Perception
How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.
Now Playing: Science for the People

#513 Dinosaur Tails
This week: dinosaurs! We're discussing dinosaur tails, bipedalism, paleontology public outreach, dinosaur MOOCs, and other neat dinosaur related things with Dr. Scott Persons from the University of Alberta, who is also the author of the book "Dinosaurs of the Alberta Badlands".