Author(s): ZHANG, K., JIANG, L., ZHANG, X., ZHANG, D., CAO, C., Institution: SOUTHEAST UNIVERSITY, Country: CHINA, Abstract-ID: 1268

Smartphone Use and Emotional Well-Being in Generation Z College Students: A Sport and Lifestyle Perspective

smartphone use; negative affect; lifestyle behavior; hippocampus; mental well-being

Introduction
Smartphone engagement has become a dominant lifestyle behavior among Generation Z college students and may compete with time allocated to physical activity. While regular exercise is known to support hippocampal plasticity and emotional well-being, the neural and affective profile associated with habitual smartphone use remains unclear. From a lifestyle neuroscience perspective, understanding how sedentary digital behavior relates to intrinsic brain activity may help contextualize its potential implications for mental health in physically active populations. This study examined associations between weekly smartphone use, intrinsic hippocampal and dorsolateral prefrontal cortex (DLPFC) activity, and affective states in healthy college students.

Methods
Fifty healthy college students participated in this cross-sectional study. Weekly smartphone use time was obtained from built-in screen-time statistics. Positive affect (PA) and negative affect (NA) were assessed using the PANAS. Resting-state fMRI data were acquired on a 3.0 T scanner. Fractional amplitude of low-frequency fluctuation (fALFF) was calculated to index intrinsic neural activity. Mean fALFF values were extracted from bilateral hippocampus and DLPFC using the AAL atlas. Pearson correlations examined associations between smartphone use, regional fALFF, and affective measures. Hierarchical regression analyses tested whether regional intrinsic activity explained additional variance in NA beyond smartphone use. Quadratic regression was used to explore potential nonlinear effects.
Results
Weekly smartphone use was positively associated with NA (r = 0.38, p < 0.01) and left hippocampal fALFF (r = 0.37, p < 0.01). No significant associations were observed between smartphone use and PA or DLPFC fALFF (p > 0.05). In regression analyses, smartphone use remained a significant predictor of NA (p = 0.005), whereas hippocampal and DLPFC fALFF did not explain additional independent variance. Quadratic modeling indicated a significant linear association without evidence of a robust nonlinear effect. The model explained approximately 19 percent of variance in NA.
Conclusion
Greater habitual smartphone use was associated with elevated negative affect and increased hippocampal intrinsic activity, suggesting a neural-affective profile linked to sedentary digital engagement. These findings highlight the importance of considering competing lifestyle behaviors when addressing emotional well-being in sport and health contexts.