Tempo de ecrã, qualidade de sono e desempenho cognitivo em crianças de idade escolar

Abstract

Theoretical Background: The excessive use of electronic devices has been identified as one of the main sources of disruption to sleep hygiene among young people and is frequently associated with a range of negative consequences for physical and mental health. Additionally, there are potential cognitive consequences, such as poorer levels of attention and executive functioning. As executive functions are a central component of human self-regulation and self-monitoring, it becomes pertinent to examine the factors that might negatively impact these capacities during early years of compulsory schooling. The present study aimed to investigate the relationship between screen time, sleep quality, and cognitive performance in Portuguese school-aged children. Method: The selected sample consisted of 94 children aged between 7 and 10 years (M = 8.53 years; SD = .876), attending the 2nd, 3rd, and 4th grades of a private school in the Lisbon district, with 53.2% (N = 50) being female and 46.8% (N = 44) male. The instruments used included both parent-reported and direct performance measures. To assess screen time and sleep quality, the QTEC and the CSHQ-PT were administered to the parents, respectively. To evaluate attention and executive functioning, the children were administered the Verbal Fluency test, the Signal Cancellation task, and the Trails (A and B) from the BANC, along with the Digit Span subtest from the WISC-III and a computerised Go/No-Go task. Additionally, The CPM-P was also applied to control for non-verbal logical reasoning. Results: The findings showed that, although no significant and generalised association was found between screen time and the Sleep Disturbance Index (IPS), a significant correlation was found between weekday tablet use and the IPS. The longer the screen time on this device, the poorer the sleep quality. Regarding cognitive performance, no significant associations were observed with sleep quality, but marginal correlations were found between weekend screen time for school activities and inhibitory control, as well as a significant association between video game console use and phonemic verbal fluency. The more screen time spent on school-related activities over the weekend, the poorer the performance on the inhibitory control task. Similarly, increased time spent on video game consoles during the weekend was associated with reduced verbal initiative and cognitive flexibility Conclusion: Screen exposure may present different relationships depending on the type of device and the time of use (weekday vs. weekend), contributing to varying patterns both in terms of sleep and cognitive performance. However, these relationships are not as widespread nor as strong as is often suggested in literature. Factors such as the type of the device, the nature of the activity (school vs. leisure), and the time of use (weekday vs. weekend) appear to play relevant roles. Moreover, family context and other environmental factors, such as educational support and parental supervision, emerge as key variables to consider when assessing the impact of screen use and sleep quality on children's cognition. Future studies with more diverse samples and the inclusion of objective measures of screen time and sleep quality could not only enrich the understanding of these associations but also provide more precise guidance for awareness-raising initiatives within educational and family settings.

Date of Award	5 Dec 2024
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Joana Rodrigues Rato (Supervisor)