Recent theoretical and empirical accounts maintain that different indices of smartphone use—including problematic smartphone use, phone-checking, and screen time—tap distinct facets of smartphone use. This highlights the importance of disentangling potentially unique associations between facets of smartphone use and psychological distress outcomes. The present study examined fine-grained relationships between several smartphone-use indices and facets of psychological distress. Further, we probed whether sex modulated the relationships between smartphone-mediated behaviours and distress outcomes. Using structural equation modelling, we analysed data from young adults (N = 364) and evaluated the associations of smartphone-related behaviours—problematic use, phone checking, and overall screen time—with depression, anxiety, and stress. We found that phone-checking frequency predicted greater depression, anxiety, and stress levels, while problematic smartphone use predicted anxiety levels above and beyond the effects of other indices. Further, smartphone screen time predicted depression, but not other distress-related outcomes. We also found an interaction effect such that the positive relation between problematic smartphone use and stress was more pronounced for females than males. Our results held true when key covariates (age, sex, socioeconomic status, negative affect, and neuroticism) were accounted for. These findings underscore the importance of distinguishing indices of smartphone use in relation to psychological distress.

To find out how the representations of structured visual objects depend on the co-occurrence statistics of their constituents, we exposed subjects to a set of composite images with tight control exerted over (1) the condi- tional probabilities of the constituent fragments, and (2) the value of Bar- low’s criterion of “suspicious coincidence” (the ratio of joint probability to the product of marginals). We then compared the part verification re- sponse times for various probe/target combinations before and after the exposure. For composite probes, the speedup was much larger for tar- gets that contained pairs of fragments perfectly predictive of each other, compared to those that did not. This effect was modulated by the sig- nificance of their co-occurrence as estimated by Barlow’s criterion. For lone-fragment probes, the speedup in all conditions was generally lower than for composites. These results shed light on the brain’s strategies for unsupervised acquisition of structural information in vision.