Stephanie Santo

The Smell of Alcohol Might be Enough to Influence your Attention

Reference: Monk, R. L., Qureshi, A. D. A. M., Wernham, G., & Heim, D. (2022). Does the smell of alcohol make it harder to resist? The impact of olfactory cues on inhibitory control and attentional bias. Psychopharmacology, 239(7), 2109-2118.

It’s amazing how smells can take you back to a particular time in your life. Just one whiff of a familiar smell can bring back memories, good and bad. For instance, the smell of alcohol can impact our thoughts and behaviors depending on what we associate it with. Those with negative memories associated with alcohol are more likely to avoid it, whereas those with positive memories tend to seek it out. People who work in the food and beverage industry understand this principle, using it to sell things. 

There is also a neuroscientific basis for who is more likely to drink after smelling alcohol. For people who are heavy drinkers, smelling alcohol can increase activation in the ventral tegmental and nucleus accumbens, areas of the brain associated with reward activation. In other words, they may be more likely to drink because the smell reminds a part of their brain that they will feel a sense of reward afterward; 1). 

Previous research has identified that the sights and sounds associated with alcohol, not just the smell, may influence people (e.g., 2). For instance, imagery of bars or the sounds of glass clinking may have an impact on one’s memory the same way that smelling an alcoholic beverage can. This discovery was identified through the use of go/no-go tasks. In these tasks, participants are presented with a series of stimuli (e.g., words or colors) for a brief period, and are told to respond (“go”) by pressing a button to one stimulus and withhold a response (“no-go”) to all other stimuli. These tasks are meant to measure impulse control – how well people can inhibit a response. In prior research, it was found that participants exposed to sounds and visuals relating to alcohol did worse on both go/no-go tasks and Stroop tests (3).

Example of a go-no-go task. Image from Testable.org.

Recently, researchers from the Liverpool Centre for Alcohol Research were interested in the impact of the smell of alcohol on attention and impulse control. The researchers designed two studies that examined the response of participants to decisions made under uncertainty, the first of which utilized the go-no-go task.

In the first study, the researchers sorted 40 social drinkers (i.e., people who drink frequently in social settings such as parties), into a neutral smell condition or an alcoholic smell condition. In the neutral smell condition, participants wore a mask with citrus oil, whereas in the alcoholic smell condition, participants wore a mask with vodka. Participants were then asked to perform an association task using two picture sets. Participants in the alcohol condition were shown a set of bar-related pictures – one beer bottle, and 25 water bottles. Participants in the neutral condition were shown the letters of the alphabet. The participants were asked to respond to target stimuli (either the letter K, or the beer bottle) by clicking a button, while ignoring every other image. Then, the image sets were then flipped – participants in the alcohol condition were shown the neutral images, whereas participants in the neutral condition were shown the bar-related images. The entire association task took 30 minutes, with breaks to prevent fatigue.

What did the researchers find? On average, there were more inaccuracies in the responses of participants in the alcohol condition than in the neutral condition. There was no difference in the type of cue (visual or olfactory) on results. These outcomes suggest that people who smell alcohol or see alcohol-related images are more likely to experience attention and inhibitory impairments.

Example of a Stroop test. When participants are asked to identify the color of the word, they tend to have more difficulties when the color and meaning of the word are incongruent (bottom panel) than when they are congruent (top panel). In the incongruent conditions, participants have to inhibit the “meaning” response. Image from Wikipedia.

In the second study, the researchers selected another 40 social drinkers and used the same olfactory conditions, either vodka or citrus. This time, participants were tasked with a Stroop test, a different measure of attention and impulse control. In the Stroop test (example shown above), participants are shown different words in different colors and asked to press a button that corresponds to either the color of the word or the meaning of the word. In some trials, the color of the word often does not match the meaning of the word. For instance, the word “blue” might be written in green ink. The task was meant to measure attentional bias (how well participants paid attention during the task) and general accuracy (the number of correct answers).

What did they find? In this case, participants exposed to the smell of alcohol did worse on the Stroop test.

On the whole, people in the alcohol condition tended to perform worse on the go-no-go task than people in the neutral conditions, and this outcome may be due to the olfactory cues. That said, perhaps participants’ error rates can be better explained by the scent of alcohol’s negative impact on their motor skills rather than directly impacting their attention and impulse control. Also notable is the fact that both studies showed different results. In study 1, people in the alcohol condition were better at inhibiting their impulses, but that may be because the bar images were more varied than the neutral image set. In study 2, there was no difference in attentional bias for words between the neutral and alcohol conditions – which suggests that their attention span was not strongly influenced by the smell of alcohol. Why did the researchers find different outcomes across the two studies? Although both studies measured attentional outcomes, they used different tests to do so, which could account for the different results. However, this possibility is only speculative, and more research studies need to be conducted before coming to a definitive conclusion.

The next time you are around alcohol, remember that the effects of alcohol’s smell alone is more powerful than you may have thought, especially when it comes to your attention and inhibition!

Additional References

(1) Kareken DA, Claus ED, Sabri M, Dzemidzic M, Kosobud AEK, Radnovich AJ et al (2004) Alcohol-related olfactory cues activate the nucleus accumbens and ventral tegmental area in high-risk drinkers: preliminary findings. Alcoholism, Clinical and Experimental Research 28(4):550–557

(2) Kreusch, F., Vilenne, A., & Quertemont, E. (2013). Response inhibition toward alcohol-related cues using an alcohol go/no-go task in problem and non-problem drinkers. Addictive Behaviors, 38(10), 2520-2528. https://doi.org/10.1016/j.addbeh.2013.04.007 

(3) Monk RL, Sunley J, Qureshi AW, Heim D (2016) Smells like inhibition: the effects of olfactory and visual alcohol cues on inhibitory control. Psychopharmacology 233(8):1331–1337. https://doi.org/10.1007/s00213-016-4221-1