Screen time apps that allow smartphone users to manage their screen time are assumed to combat negative effects of smartphone use. This study explores whether a social media restriction, implemented via screen time apps, has a positive effect on emotional well-being and sustained attention performance. A randomized controlled trial (N = 76) was performed, exploring whether a week-long 50% reduction in time spent on mobile Facebook, Instagram, Snapchat and YouTube is beneficial to attentional performance and well-being as compared to a 10% reduction. Unexpectedly, several participants in the control group pro-actively reduced their screen time significantly beyond the intended 10%, dismantling our intended screen time manipulation. Hence, we analyzed both the effect of the original manipulation (i.e. treatment-as-intended), and the effect of participants’ relative reduction in screen time irrespective of their condition (i.e. treatment-as-is). Neither analyses revealed an effect on the outcome measures. We also found no support for a moderating role of self-control, impulsivity or Fear of Missing Out. Interestingly, across all participants behavioral performance on sustained attention tasks remained stable over time, while perceived attentional performance improved. Participants also self-reported a decrease in negative emotions, but no increase in positive emotions. We discuss the implications of our findings in light of recent debates about the impact of screen time and formulate suggestions for future research based on important limitations of the current study, revolving among others around appropriate control groups as well as the combined use of both subjective and objective (i.e., behavioral) measures.

Ranking-space: magnitude makes sense through spatially scaffolded ranking

As part of the demands of a globalized and interconnected world, studying second languages has become a major priority. Bilingual programs implemented in recent decades have motivated an educational strategy in which content area courses are taught through L2. The potential costs of this strategy in academic performance are debated, especially in challenging areas such as mathematics. The present work systematically reviewed 71 papers based on experiments measuring mathematics performance in bilinguals in order to establish if bilinguals show a (dis)advantage in mathematics compared to monolinguals. The results of a total of 305,136 participants (57,703 bilinguals and 247,503 monolinguals) show that bilingualism does not seem to affect mathematical performance, but this is dependent on whether subjects are highly proficient bilinguals. This type of bilingual may only be affected by lower reaction times depending on the testing language. On the other hand, low language proficiency negatively impacts mathematical performance. Lastly, bilingualism enhances mathematical encoding and processes in non-language-related tasks.

Previous work has shown that serial order in verbal working memory triggers the spontaneous formation of a mental line on which the sequence of items is coded. Recent studies show that the orientation (horizontal versus vertical) and coding direction (e.g., left-to right versus right-to-left) of this spatialization can flexibly be adapted to match the task context. Here we investigate whether people spatialize a sequence of verbal items using multiple spatial dimensions simultaneously if the task probes such strategy. In two experiments, participants had to encode a letter sequence and maintain it for later reproduction. In between, they performed a vowel-consonant classification task on items that were part of the memorized sequence to probe for spatialization. Classification occurred via horizontal or vertical saccade responses that varied unpredictably from trial to trial, with a fixed (Experiment 1) or variable (Experiment 2) stimulus-response mapping. Spatial biases were observed for both horizontally (early-left, late-right) and vertically (early-up, late-down) oriented classification trials (mixed within the same block), indicating that the item sequence was spatialized in a multidimensional format (i.e. exploiting both the vertical and horizontal axes). The horizontal and vertical biases were also correlated with each other. Overall, we show for the first time that task context can probe a strategy in which people spatially code a sequence of verbal items using multiple spatial dimensions simultaneously.