Investigating the impact of preterm birth on theory of mind development in five-year-old children

Abstract Background Behavioural studies suggest atypical/delayed development of “theory of mind” (ToM; our ability to reason about others’ mental states) following preterm birth. We used functional magnetic resonance imaging (fMRI) to test whether behavioural differences are likely the result of preterm birth specifically impacting neural ToM development, as evidenced by differences in brain regions recruited for ToM reasoning (“ToM network”). Methods Using fMRI and behavioural ToM tasks with five-year-old children born at 24-42 weeks’ GA, we tested for an effect of gestational age (GA) on behavioural ToM performance, functional maturation of the ToM network, response magnitude to ToM movie scenes, and inter-region correlations. Additionally, we leveraged an open dataset and intersubject correlation analyses to measure similarity of neural ToM responses within and across preterm- and term-born children; including younger (3–4-year-old) children via the open dataset enabled testing for evidence of developmental delays among children born preterm. Results Behaviourally, preterm-born children scored lower on our primary behavioural ToM task, and on a measure of receptive language, compared to term-born children. Neurally, ToM network responses during a short movie were similar across preterm- and term-born children. There was no effect of GA on functional maturation or on the response magnitude in ToM regions to two of three ToM scenes. Response magnitude in ToM regions to a third scene was lower among preterm-born children relative to term-born children, but responses to this scene were also low among adults. Both term- and preterm-born children showed functionally distinct ToM network responses. While ToM network responses were more heterogenous among preterm-born children, responses in individual preterm-born children were most similar to (correlated with) same-age term-born children, relative to other preterm-born children or younger (3–4-year-old) term-born children. Conclusions Preterm birth does not preclude broadly similar functional development in ToM brain regions by age five years.