Digital Habit and Neural Indicators of Well-Being

Many social media platforms minimize the effort required to open and engage with an application, which may support automatic or habitual use. Introducing friction at the moment of app access may interrupt habitual responding and provide an opportunity for more deliberate choice. This randomized, longitudinal study tests whether a friction-based smartphone intervention reduces the average daily time young adults spend using a self-selected social media application. The secondary objective is to determine whether the intervention improves digital well-being. Additional behavioral and neural measures will be used in exploratory analyses of cognitive processes and individual differences associated with intervention response.

The study consists of a baseline laboratory visit, an approximately 14-day study period, and a post-intervention laboratory visit. During the baseline visit, participants will complete a measure of digital well-being and provide recent smartphone screen-time information. Functional near-infrared spectroscopy (fNIRS) will be used to measure cerebral hemodynamic activity while participants complete tasks assessing working memory, sustained attention, and inhibitory control and during a period of naturalistic smartphone and social media use. Participants will also complete modified versions of the cognitive tasks containing socially salient distractors.

During the approximately 14-day study period, participants will complete brief daily ecological momentary assessments. Passive and system-level smartphone data will be collected through the study applications, including the duration and frequency of use of the selected social media app and indicators of engagement with the intervention. At the post-intervention visit, participants will repeat the digital well-being, behavioral, naturalistic smartphone-use, and fNIRS procedures completed at baseline.

Mixed-effects models will be used to evaluate changes over time and differences between the intervention and control conditions. The primary analysis will test whether the intervention reduces average daily time spent using the selected social media application. The secondary analysis will test whether the intervention produces a change in digital well-being from baseline to the post-intervention assessment. Relationships involving cognitive performance, neural responses, and other individual-difference measures will be examined in exploratory analyses.