A recently published study provides new insight into the brain mechanisms underlying addictive smartphone use. The research, which appears in the journal Addictive Behaviors, found evidence of altered neural activity in response to smartphone cues among compulsive smartphone users.
The corresponding author of the study, Robert Christian Wolf, became interested in examining compulsive smartphone use after witnessing people who were “spending more time with their smartphone than with their family or friends.”
“In the past years, increased concerns have been expressed in the scientific literature regarding potentially adverse effects on physical and mental health of excessive smartphone use. This behavior has been frequently referred to as ‘smartphone addiction’. Recent research has highlighted behavioral similarities between excessive smartphone use and other addictive disorders, such as Internet Gaming Disorder,” explained Wolf, who is the deputy director at the Department of General Psychiatry at Heidelberg University in Germany.
“We employed functional magnetic resonance imaging (fMRI) to investigate cue-related activity in individuals with smartphone addiction, as defined by validated psychometric scales. Cue reactivity has been one of the most important and therapeutically relevant paradigms in addiction research for decades.”
“Cue reactivity is based on conditioning mechanisms, in which over time, salient stimuli (cues) are tightly linked to rewarding properties. Cue reactivity can trigger the execution of certain behavioral acts that over time can lead to addiction. Neural correlates of cue reactivity in other addictive disorders (e.g. alcohol use disorder) are well known, but at the time we conducted our study, nothing was known about the neural signature of cue reactivity in smartphone addiction,” Wolf said.
In the study, the researchers compared the brain activity of 21 individuals who fit the criteria for smartphone addiction to 21 matched controls as they viewed a variety of images, including smartphones. “We employed an fMRI-paradigm with neutral stimuli and cues. Cues were smartphones, either switched off or on,” Wolf explained.
Those who fit the criteria for smartphone addiction reported that they constantly checked their smartphone, missed work due to smartphone use, had difficulties concentrating because of their smartphone, and felt impatient and fretful in the absence of their smartphone.
The researchers observed differences in neural activity in several brain regions, including the anterior cingulate cortex, inferior frontal gyrus, and medial prefrontal cortex as well as
in cerebellar and occipital regions. They also found neural activity differences between the two groups when viewing active vs. inactive smartphones.
“Persons with smartphone addiction showed a pattern of increased and decreased activity in specific brain regions, i.e. increased activity in parts of the brain that process salience, together with decreased activity in parts of the brain that subserve cognitive control or control,” Wolf told PsyPost.
“Differences in cortical activity were also found depending on whether smartphones were presented in an ‘off’ or ‘on’ condition. Overall, similar neural patterns of cue reactivity have been previously observed in other addictive disorders, both substance-use disorders and behavioral addictions.”
But the study — like all research — includes some limitations.
“The relatively modest sample size of this study should be acknowledged, as much as the cross-sectional study-design. Robust inference on causality cannot be made. Also, the CR-paradigm was not balanced out with respect to specific apps. We clearly need more data, particularly longitudinal studies in well-powered samples stratified by age, since adolescents and young adults are be more prone to excessive smartphone use,” Wolf said.
Though the researchers use the term smartphone addiction, they do not view compulsive smartphone use as the equivalent of other addictions, like substance abuse.
“The results of our study do not necessarily imply that smartphone addiction is ‘truly’ an addictive disorder, nor do they show that something is ‘abnormal’ in brains of people meeting psychometric criteria for smartphone addiction. It should be kept in mind that smartphone addiction is not a specific diagnostic category, i.e. it is not included in any of the extant diagnostic manuals for mental disorders,” Wolf explained.
“Smartphone use needs to be treated as dimensional phenomenon that may, in its extreme manifestation, meet criteria for addictive behavior. Clearly, several biopsychosocial features may increase the likelihood for such behavior. One of them, as our study suggests, could be neural variation related to salience processing and executive control.”
The study, “Neural correlates of cue reactivity in individuals with smartphone addiction“, was authored by Mike M. Schmitgen, Juliane Horvath, Christina Mundinger, Nadine D. Wolf, Fabio Sambataro, Dusan Hirjak, Katharina M. Kubera, Julian Koenig, Robert and Christian Wolf.
