Ana Maria Portugal, PhD1; Rachael Bedford, PhD2; Celeste H. M. Cheung, PhD1; et alTeodora Gliga, PhD3; Tim J. Smith, PhD1Author AffiliationsArticle InformationJAMA Pediatr. Published online August 10, 2020. doi:10.1001/jamapediatrics.2020.2344
During toddlerhood, a peak period of neurocognitive development, increased exposure to sensory stimulation through touch screen use, may influence developing attentional control.1 While TV’s rapidly changing, noncontingent flow of sensory information has been hypothesized to lead to difficulties voluntarily focusing attention,2 video gaming’s contingent and cognitively demanding sensory environments may improve visual processing and attention.3 Toddler touch screen use involves both exogenous attention, driven by salient audio-visual features, and endogenous/voluntary control, eg, video selection and app use.4,5
The current study compared high– and low–touch screen users on a gaze-contingent visual search paradigm,6 assessing exogenous, saliency-based attention (single-feature trials), and endogenous attention control (conjunction trials).
Individuals aged 12 months were recruited from October 2015 to March 2016 (as part of the TABLET project5) and followed up longitudinally at 18 months and 3.5 years. Parents gave informed written consent, and the Birkbeck, University of London institutional review board approved this study. Before each visit, parents were asked, “On a typical day, how long does your child spend using a touchscreen device (tablet, smartphone or touchscreen laptop)?” Participants were recruited as high users and low users based on median use of 10 minutes per day reported in a previous survey sample.5 At 18 months and 3.5 years, user groups were reassigned using the within-sample median (15 minutes per day). At recruitment, groups were matched on developmental level (Mullen Scales of Early Learning), age, sex, background TV (parent-reported minutes per day), and mother’s education.
The visual search task was administered at 18 months and 3.5 years (Tobii TX300 eye tracker with 120-Hz tracking, 60-cm distance, 5-point calibration). Arrays were presented (single feature [target red apple among blue apples; set sizes 5 and 9] or conjunction [target red apple among blue apples and slices of red apples; set sizes 5, 9, and 13; only set sizes matched across conditions were analyzed, ie, 5 and 9) for 4 seconds or until the target was fixated. Trials were presented continuously, grouped into blocks: (1) 3 single feature, fixed order; (2) 1 single feature, 9 conjunction, randomized; and (3) 4 single feature, 9 conjunction, randomized. P values were 2-sided and were significant at less than .05. SPSS version 184.108.40.206 (SPSS Inc) was used. Analysis began November 2018 and ended in November 2019.
Of 56 infants recruited, 49 were followed up longitudinally at 18 months and 46 were followed up at 3.5 years. Data quality and accuracy did not differ significantly across groups. Linear generalized estimating equations for saccadic reaction time (SRT) (Figure) were run with an unstructured correlation matrix (deviation from preregistered 3.5-year analysis of variance; https://osf.io/fxu7y) to include missing data and treat group as a time-varying predictor (some children changed user groups over time; usage correlations: 12 to 18 months, Spearman rs = 0.78; 18 months to 3.5 years, Spearman rs = 0.33; 12 months to 3.5 years, Spearman rs = 0.31).