Access: FREE/Open Access
Exposures, Outcomes, Other
Brain/Neurocognitive , Child Development (general) , Language and Literacy Development , Technology and Digital/Screen-Based Media
The aim of this study was to explore functional connectivity (FC) within and between functional brain networks supporting imagery, language, and learning during stories presented in audio, illustrated, and animated format in preschool-age children.
Audio, illustrated, and animated stories.
Healthy children were recruited for this study via advertisement at an academic medical center.
Thirty-three healthy children were recruited for this study via advertisement at an academic medical center, which involved functional magnetic resonance imaging (fMRI) at a single visit. Twenty-seven of them completed fMRI (82%; 15 boys, 12 girls; mean 58 ± 8 months old). The fMRI protocol involved the presentation of 3 similar, unrhymed stories by the same author lasting 5 min each in audio, illustrated, and animated format during separate runs, followed by a test of factual recall. Within- and between-network functional connectivity (FC) was compared across formats involving five functional networks, which were defined via literature review and refined via a data-driven parcellation method: visual perception, visual imagery, language, Default Mode (DMN), and cerebellar association.
n=33 (children recruited); n=27 (children completed fMRI)
Measure of Functional Connectivity: within- and between- network FC measured by fMRI and compared across the following functional networks:
- visual perception
- visual imagery
- default mode (DMN)
- cerebellar association
Measure of Factual Recall: following MRI, children were asked three questions per story regarding basic factual content, whether they could hear the story well (1 = yes, 2 = no), and how interesting it was (1 = very, 2 = kind of, 3 = not very).
For illustration relative to audio, FC was decreased within the language network and increased between visual, DMN, and cerebellar networks, suggesting decreased strain on the language network afforded by pictures and visual imagery. Between-network connectivity was decreased for all networks for animation relative to the other formats, particularly illustration, suggesting a bias towards visual perception at the expense of network integration.
These findings suggest substantial differences in functional brain network connectivity for animated and more traditional story formats in preschool-age children, reinforcing the appeal of illustrated storybooks at this age to provide efficient scaffolding for language, and suggesting novel neurobiological correlates of how functional networks may contribute to this process.
Our results are in terms of mean FC during each format, while dynamic FC analyses may reveal other differences. The stories used were by the same author with a particular style, and our findings may not apply to other styles. We view this as a worthwhile tradeoff, allowing us to control for important narrative variables across formats. The three stories used were different, presented in the same order for each child. However, this design eliminated the confound of repeat exposure to the same story likely to make subsequent trials less interesting, or easier. Gradually increasing visual stimulus also minimized visual priming effects, while addressing concerns about the potential of animated content to negatively affect performance on subsequent tasks at this age (Lillard and Peterson 2011 and Lillard et al. 2015). Given technological constraints, shared reading during MRI is not currently feasible. However, audio and animation were presented in a reasonably ecological way (headphones and screen), and we suspect that greater differences between illustrated and other formats would manifest on a parent’s lap. Our sample size was relatively small (27), though respectable especially given the young age of our sample population, and exceeding sample sizes in recently published, connectivity-based analyses involving functional networks and continuous task paradigms (Bray et al. 2015; Horowitz-Kraus et al. 2018; Weber et al. 2018). Our assessment of story recall was rudimentary and administered to only 14 of 27 children, though its finding of equivalent interest and significantly lower scores for the animated story provides useful insights into our MRI results. Our sample involved Caucasian, largely higher-SES children, though general mechanisms of neural processing seem unlikely to be influenced by race, and SES-related covariates did not significantly influence our results. Our analyses were limited to five functional networks, though these were rigorously determined affording a hypothesis-driven approach that increased our statistical power. Our networks were largely defined in terms of Brodmann Areas, with some included in more than one network, yet refined via an established parcellation approach (Craddock et al. 2012).