The Effects of Technology Use on Infant Language Development: Study of an Italian Cohort

The use of technology and screen media has become increasingly prevalent in early childhood. International guidelines discourage screen media for children under two years, aside from videochats with caregivers, so that sedentary behaviour does not become a standard part of the infant's routine (Ponti et al., 2022). Despite these recommendations, parents have reported that infants between the ages of 0 and 2 are exposed to more than an hour of screen media per day (Alroqi et al., 2022; Balbinot et al., 2016) and that infants under the age of two own their own cell phones and tablets (Alroqi et al., 2022). A growing body of research cautioned that early and prolonged exposure to screen media may negatively affect several domains of child development, including language development (Operto et al., 2020). This is particularly concerning because language is used for communication and self expression (Crystal, 2018), and its development can be impacted by the quantity and quality of the language the infant is exposed to (Hart & Risley, 1995), including the ways they interact with technology and screen media. However, the measurements for infant language development as well as technology use and screen media exposure have relied primarily on parent reports, which may be subject to artifacts such as social desirability bias and recency effects. This thesis project has three main aims. The first is to validate the use of a novel, objective measure, the Language ENvironment Analysis (LENA) system for its ability to reliably measure television and electronic sounds (TV/ES) in an Italian sample. The second is to describe the acoustic environment that Italian infants are exposed to in a typical day, and to describe the pattern of the infant's language development. The third is to investigate the effect of TV/ES exposure on infant language development. Twenty-eight infants were followed longitudinally across four key milestones in linguistic development, i.e., pre-babbling, babbling, first word production, and vocabulary spurt phase. During each recording session, families were given the LENA device to record the auditory environment of the infant and completed the Italian version of the MC-BDI (Caselli et al., 2015) to confirm the infant's linguistic phase of development. A reliability analysis based on 2,100 minutes of recordings revealed no significant differences between LENA-derived and manually coded TV/ES exposure, with a weak to moderate correlation between the human coder and the LENA device. Infant media exposure was shown to vary across the first two years of life, as well as peak in specific times of the day. Mixed-effects models on child’s language development indicated significant changes across the phases of linguistic development, and a significant interaction between child vocalizations and their exposure to TV/ES. Infants with a higher exposure to TV/ES had lower vocalization counts in the vocabulary spurt phase as compared to all other phases of development. These findings support using LENA to measure TV/ES exposure on Italian-speaking infants, and support previous literature that describes how increased exposure to TV/ES may have a negative effect on infant language development. This highlights the importance in considering screen-time and related environmental factors when examining early language development.