Summary: Drinking a cup of coffee produces changes in brain connectivity that make people more alert and better prepared to shift from rest to task-focused activity — effects that are not fully reproduced by caffeine alone.
A group of Portuguese researchers reported that a standard cup of coffee reduced connectivity within the brain’s default mode network (DMN), a system active during introspection and mind-wandering. At the same time, coffee increased connectivity in the higher visual network and the right executive control network, networks associated with working memory, cognitive control, and goal-directed behavior.
Crucially, while isolated caffeine intake produced some overlap in effects, the broader pattern of network changes—especially the enhanced connectivity in visual and executive control regions—appeared specifically after drinking coffee. This suggests that the full coffee experience, beyond its caffeine content, contributes to the subjective sense of being not only awake but ready to take on tasks.
Key findings:
- Both coffee and caffeine reduced connectivity in the brain’s default mode network, a change consistent with increased readiness to shift from rest to task-related processing.
- Only drinking coffee increased connectivity in the higher visual network and the right executive control network, supporting improved readiness for external attention, working memory, and cognitive control.
- Some connectivity changes were reproduced by caffeine alone, but several effects were specific to the act and experience of drinking coffee, implying sensory, contextual, or expectancy influences beyond neurochemistry.
Source: Frontiers
For many people, the day truly starts after the first cup of coffee. The beverage is widely believed to sharpen alertness and boost efficiency.
Portuguese scientists studied habitual coffee drinkers to determine whether the wakefulness and mental sharpening attributed to coffee come entirely from caffeine’s pharmacology or whether the sensorimotor experience of drinking coffee also plays a role.
“There is a common expectation that coffee increases alertness and psychomotor functioning,” said Prof. Nuno Sousa of the University of Minho, corresponding author on the study published in Frontiers in Behavioral Neuroscience. “By probing the mechanisms behind this effect, we can explore factors that modulate it and consider any potential benefits.”
Study design and methods
The research team enrolled regular coffee drinkers who reported consuming at least one cup per day. Participants refrained from eating and from other caffeinated beverages for at least three hours before testing. Sociodemographic and baseline information was recorded, and each participant underwent two short resting-state functional MRI (fMRI) scans: one before and one approximately 30 minutes after either ingesting pure caffeine or drinking a standardized cup of coffee. During scans, participants were instructed to relax and let their minds wander.
Based on known neurochemical effects, the investigators expected changes in networks linked to the prefrontal cortex and the DMN. They observed that both coffee and caffeine reduced connectivity in the posterior DMN, consistent with a neural signature of increased readiness to move from rest to task processing.
More than a caffeine kick
Beyond the shared DMN change, drinking coffee uniquely increased connectivity in the higher visual network and the right executive control network (RECN). These regions support working memory, cognitive control, and attention to external stimuli—functions associated with being “ready for action.” Those enhancements were not present after taking caffeine alone, indicating that sensory aspects of drinking coffee (smell, taste) or psychological expectations could contribute to the effect.
“Acute coffee consumption reduced connectivity within the DMN, a network linked to internal thought while at rest,” said Dr. Maria Picó-Pérez of Jaume I University, first author of the study. “We also saw decreased connectivity between somatosensory/motor networks and prefrontal regions, while connectivity in higher visual and right executive control nodes increased after coffee. In short, subjects appeared more alert and responsive to the outside world after a cup of coffee.”
The authors note that some observed effects could be shared with other caffeinated beverages, but several changes were specific to coffee drinking. The current design could not fully separate the experience of drinking coffee from the combined effect of experience plus caffeine; additionally, relief of withdrawal symptoms remains a possible contributor that this study did not directly assess.
“We interpreted connectivity changes according to the commonly ascribed functions of the affected regions and networks, but this study did not directly measure cognitive or behavioral performance during the scans,” added Prof. Sousa. “Individual differences in caffeine metabolism could also shape responses and merit future investigation.”
About this neuroscience research news
Author: Angharad Brewer Gillham
Source: Frontiers
Contact: Angharad Brewer Gillham – Frontiers
Image credit: Neuroscience News
Original Research: Open access. “Coffee consumption decreases the connectivity of the posterior DMN at rest” by Nuno Sousa et al., Frontiers in Behavioral Neuroscience
Abstract
Coffee consumption decreases the connectivity of the posterior DMN at rest
Regular coffee consumers often report feeling more alert and more effective in motor and cognitive tasks after a cup, yet the underlying neurobiological correlates remain under study. Using resting-state fMRI and functional connectivity analyses in habitual coffee drinkers, this study shows that coffee consumption reduces connectivity in the posterior default mode network and between somatosensory/motor networks and prefrontal areas, while increasing connectivity in nodes of the higher visual network and the right executive control network. Caffeine alone reproduced some but not all of these effects, helping to distinguish the pure neurochemical action of caffeine from the broader experience of drinking coffee.