Caffeine alone only partially replicates the effects of a cup of coffee by activating areas of the brain that make you feel more alert, but not working memory and concentration.
For many people, the day only begins with the first cup of coffee. Coffee is often thought to make us more alert, which is why people drink it to wake up and improve their performance. A team of Portuguese scientists studied coffee drinkers to find out whether this wake-up effect depends on the properties of caffeine or whether it’s just the experience of drinking coffee.
“There is a general expectation that coffee increases attention and psychomotor functions,” says Professor Nuno Sousa from the University of Minho, corresponding author of the study Frontiers of behavioral neuroscience and editor-in-chief of the magazine. “When the mechanisms underlying a biological phenomenon are better understood, opportunities open up to explore the factors that can modulate it and even the potential benefits of that mechanism.”
A shot of caffeine
The scientists recruited people who drank at least one cup of coffee per day and asked them to avoid consuming caffeinated drinks for at least three hours before the study. They surveyed participants to collect sociodemographic data and then gave them two fMRI scans of their brains: one before and one 30 minutes after consuming caffeine or drinking a standardized cup of coffee. During the fMRIs, participants were asked to relax and let their thoughts wander.
Because of the known neurochemical effects of drinking coffee, researchers expected that fMRI scans would show that people who drank coffee had greater integration of networks associated with the prefrontal cortex, which is associated with executive memory, and the Brain network that is involved by default in the processes of introspection and self-reflection. They found that default mode network connectivity decreased after both drinking coffee and caffeine, suggesting that consuming caffeine or coffee increased people’s willingness to transition from rest to work on tasks.
Waking up on the good side of the bed
Drinking coffee also increased connectivity in the higher visual network and the right executive control network, parts of the brain involved in working memory, cognitive control and goal-directed behavior. This did not occur when participants only drank caffeine. In other words, if you want to feel not only awake but also ready for action, caffeine alone isn’t enough: you need the experience of drinking that cup of coffee.
“Coffee consumption reduced functional connectivity between brain regions of the default mode network, a network associated with self-referential processes when participants are at rest,” says Dr. Maria Picó-Pérez from Jaume I University, lead author. “Functional connectivity between somatosensory/motor networks and the prefrontal cortex also decreased, while connectivity in regions of the higher visual network and the right executive control network increased after drinking coffee.” “In simple words: the subjects were more ready to act and more attentive to external stimuli.”
“Given that some of the effects we found were reproduced by caffeine, we might assume that other caffeinated drinks would share some of these effects,” Picó-Pérez added. “Others, however, were specific to coffee consumption and were based on factors such as the particular smell and taste of the drink or the psychological expectation associated with consuming that drink.”
The authors noted that it is possible that the experience of drinking decaffeinated coffee could confer these benefits: In this study, it was not possible to distinguish the effects of the experience alone from the experience in combination with caffeine. There is also a hypothesis that the benefits reported by coffee drinkers may be due to relief from withdrawal symptoms, which was not tested in this study.
“Changes in connectivity were examined during a resting state sequence. “Any association with psychological and cognitive processes is interpreted based on the common function attributed to the regions and networks found, but has not been directly tested,” Sousa warned. “In addition, there could be individual differences in caffeine metabolism between participants that would be interesting to explore in the future.”
REFERENCE
Coffee consumption reduces the connectivity of the later Default Mode Network (DMN) when idle