Even a short period away from your smartphone can lead to noticeable shifts in brain activity, according to new research published in the journal Computers in Human Behavior. Scientists discovered that just 72 hours of smartphone restriction altered activity in brain regions linked to reward and self-control. These changes suggest that our constant connection to smartphones may have a more significant impact on our brains than we realize, potentially influencing how we process rewards and manage impulses.
Smartphones have become indispensable tools in modern life, seamlessly integrated into our daily routines. For many, these devices are not just helpful gadgets but are constantly in use, blurring the lines between necessity and habit. This widespread and frequent smartphone use has sparked interest among researchers who are keen to understand the potential effects of this technology on our well-being and brain function.
Some experts have even raised concerns about whether excessive smartphone use might share similarities with behaviors seen in addictive disorders. While the term “smartphone addiction” is debated among specialists, there’s growing agreement that heavy smartphone use can have negative consequences for both our physical and mental health.
To better understand these potential impacts, researchers decided to investigate what happens in the brain when people take a break from their smartphones. They were particularly interested in how restricting smartphone use affects brain responses related to cues, or triggers, associated with smartphone use, and whether these brain changes are linked to feelings of craving. Learning more about these neural mechanisms could help us understand if excessive smartphone use shares similarities with other behaviors that involve reward and craving, such as gaming or substance use.
Previous studies have shown that individuals who use smartphones excessively exhibit some differences in brain structure and function compared to those who use them less. The new study aimed to explore whether these brain differences are fixed or if they can change with a period of smartphone restriction.
“Smartphones have become an integral part of modern life, but concerns are growing about their potential impact on mental health and brain function,” said study author Robert Christian Wolf, the deputy director of the Department of General Psychiatry at Heidelberg University Hospital.
“We were particularly interested in how short-term smartphone restriction affects brain activity related to reward processing and attention. Given the increasing discussions around digital well-being, we wanted to explore whether temporary abstinence from smartphone use leads to measurable changes in neural responses.”
To conduct their study, the researchers recruited 25 young adults who regularly used smartphones. Participants were between 18 and 30 years old and were screened to ensure they were not experiencing internet gaming disorder or other significant mental health conditions. The study involved two sessions in a brain scanner, spaced 72 hours apart. In the first session, participants underwent a brain scan using a technique called functional magnetic resonance imaging, or fMRI, which measures brain activity by detecting changes in blood flow. Before this first scan, participants completed questionnaires to assess their smartphone use habits, craving levels, and mood.
After the first brain scan, participants were asked to significantly restrict their smartphone use for the next 72 hours. This meant minimizing their use of smartphones, substitute devices, and apps for anything beyond essential work, daily tasks, or communication with close contacts. During this restriction period, participants did not have their smartphone usage directly monitored, but they were asked to complete brief questionnaires on a device to track their cravings, well-being, daily activities, and smartphone use. However, the results from these daily questionnaires are being analyzed separately and were not the focus of this particular publication.
Seventy-two hours later, participants returned for a second brain scan, again using fMRI, and repeated the mood and craving questionnaires. During both brain scan sessions, participants completed a specific task designed to examine their brain responses to smartphone cues. In this task, participants were shown blocks of images. Some blocks contained neutral images, like everyday objects. Other blocks showed pictures of smartphones that were turned off and inactive. Finally, some blocks displayed pictures of smartphones that were turned on and in use. By comparing brain activity when viewing these different types of images, researchers could assess how the brain reacted to smartphone-related cues before and after the period of smartphone restriction.
The researchers analyzed the fMRI data to identify changes in brain activity between the first and second scan sessions, particularly focusing on brain regions known to be involved in reward processing and attention. They looked at how brain activity changed when participants viewed smartphone images compared to neutral images, and when viewing turned-on smartphones compared to turned-off smartphones.
They also examined whether these brain activity changes were related to individual differences in smartphone use habits, craving scores, and mood. Finally, the scientists explored if the observed brain activity changes were linked to specific brain chemicals, such as dopamine and serotonin, by using existing maps of neurotransmitter receptor distributions in the brain.
Surprisingly, an analysis of the questionnaire data did not show any significant changes in mood or craving levels after the 72-hour smartphone restriction period. However, the brain scans told a different story. When looking at brain responses to smartphone images in general (both turned-on and turned-off) compared to neutral images, the researchers found increased activity in the anterior cingulate cortex and the nucleus accumbens after the 72-hour restriction.
These brain regions are known to be important in processing rewards and are often implicated in craving and impulsive behaviors. This increase in activity suggests that even though participants didn’t report feeling more craving on questionnaires, their brains were showing a heightened response to smartphone cues after the break.
“One interesting finding was that after 72 hours of smartphone restriction, we saw increased activation in reward-related brain areas when participants were exposed to smartphone-related cues,” Wolf told PsyPost. “This pattern is similar to what is observed in substance-related craving studies, suggesting that smartphone use may engage the brain’s reward system in a comparable way. However, we did not see significant changes in participants’ self-reported psychological measures, which was somewhat unexpected.”
In contrast, when the researchers examined brain responses specifically to images of turned-on smartphones compared to turned-off smartphones, they found decreased activity in several brain regions after the restriction period, including the middle frontal gyrus and the superior parietal lobule. These areas are involved in various functions, including attention, visual processing, and motor control. The decrease in activity in these regions when viewing turned-on smartphones might indicate that these cues became less attention-grabbing or stimulating after a period of smartphone restriction.
Interestingly, the researchers also found a link between activity in the parietal cortex and craving. This suggests that this brain region may play a role in the subjective experience of craving related to smartphone use. Their analysis also indicated that the observed brain activity changes were associated with systems in the brain that use dopamine and serotonin, neurotransmitters known to be involved in reward and addiction.
“Our study suggests that even a short break from smartphone use can lead to changes in brain activity, particularly in regions associated with reward and self-control,” Wolf explained. “These findings indicate that excessive smartphone use may influence brain function in ways similar to other rewarding behaviors. However, the changes we observed were neural rather than behavioral, meaning that longer-term restrictions or interventions might be necessary to produce noticeable psychological effects.”
As with any study, there are some limitations to note.
“Our study focused on short-term restriction, so we don’t know how long-lasting these neural effects might be,” Wolf said. “Additionally, we did not assess real-life behavioral changes, such as whether participants felt less distracted or more focused. Another key limitation is that we cannot determine whether the observed brain activity changes are a cause or a consequence of smartphone use patterns. More research is needed to explore the long-term effects and potential interventions.”
Looking ahead, the researchers are interested in understanding the longer-term effects of smartphone use on brain activity.
“Our goal is to deepen our understanding of how smartphone use influences brain activity over time, particularly in relation to attention, mood, and cognitive control,” Wolf said. “Future research could examine whether extended reductions in smartphone use lead to measurable behavioral changes or neural adaptations. Additionally, we aim to explore individual differences to better understand why some individuals may be more prone to excessive smartphone use than others.”
The researchers also emphasize that this study is not intended to demonize smartphones.
“Our study is not about portraying smartphones in a negative light but rather about understanding their impact on the brain,” Wolf told PsyPost. “Technology offers many benefits, but it’s important to recognize how our habits shape neural activity and overall well-being. Striking a balance and using digital devices mindfully may be key to fostering a healthier relationship with technology in general and, more specifically, with smartphones.”
The study, “Effects of smartphone restriction on cue-related neural activity,” was authored by Mike M. Schmitgen, Gudrun M. Henemann, Julian Koenig, Marie-Luise Otte, Jakob P. Rosero, Patrick Bach, Sophie H. Haage, Nadine D. Wolf, and Robert C. Wolf.
