‘That Caffeine Fix’
A study by addiction researcher Nicolas Koranyi and colleagues suggests that so-called ‘coffee lovers’ may not be enjoying their java juice as much as they think.
Published in the Journal of Psychopharmacology, this study draws connections between heavy coffee drinkers and persons with substance use disorders.
“The development and the maintenance of drug addiction is the result of a selective sensitization of brain regions that are relevant for wanting without a corresponding increase in liking”, says the study.
Researchers collected a total of 56 students – 24 of whom consumed more than three cups of coffee per day – and presented them with images of various images. Participants were asked to divide images into different categories with different keys on a keyboard.
This Implicit Association Test (IAT) took place over two rounds – one of which was focused on wanting, while the other was focused on liking.
Implicit Association Tests quantify a participant’s mental associations by tracking the speed at which they respond to the prompt given. The image below, created by the research team, helps explain how this IAT was designed.
Each image above shows a screenshot of a potential image in the study, with the pair of parallelograms below each screenshot representing the two keys that students can press. The key that is shaded represents the correct answer to each prompt.
Students are only asked to sort the images between those of coffee and those of juice. The statements dictating wanting or liking serve to test the strength of mental associations with each image.
For example, in the third image, the correct response would be to press the key to the right, which identifies the center image as coffee. Since this screen groups the categories ‘coffee’ and ‘positive’, you would expect someone who drinks lots of coffee to slam down the right key faster than someone who doesn’t.
Except that’s not what happened.
While frequent consumers answered far more quickly for wanting, their results for liking coffee were nearly identical to those who drank it far less.
This indicates the foundation for addiction the researchers highlighted earlier – a large disconnect between the wanting and the liking of a substance.
“The main difference between highly addictive drugs and substances with lower addictive strength [like caffeine] may mainly be a quantitative rather than a qualitative one”, the article warns.