Nearly 15 million infants are born preterm every year. Research shows that compared to their full-term peers, individuals born preterm are more likely to have lower academic scores and be less wealthy later in life. Some suggest that brain connectivity as measured by diffusion tensor imaging (DTI) may underly these results. Critically, these differences have not been substantiated quantitatively. We performed quantitative meta-analyses to evaluate overarching patterns from articles that reported DTI metrics from the corpus callosum (CC), the largest white matter structure in the brain, in neonates and children/adolescents who were born pre-term and full-term. The DTI literature was reviewed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Two meta-analyses, considering publication bias and study heterogeneity, were performed onfractional anisotropy scores from the CC from eligible articles that scanned individuals at 39.9±1.1 weeks (i.e., neonates) and 14±4.13 years of age (i.e., children/adolescents). Meta-analyses for neonates and children/adolescents revealed no significant differences between those born preterm and full-term in the CC. Children/adolescents samples were characterized by significant publication bias and high interstudy heterogeneity, whereas the neonate samples were not. The findings challenge the current state of understanding of white matter microstructure in the CC related to preterm birth. Results highlight the need for further research to better understand the dynamics among factors that can influence neural development in preterm children.

A study by Giffin and colleagues (2017) found the effect of a verbal label on the explanation of an unfamiliar phenomenon: when a name is used, people's judgments are more likely to express the belief that the phenomenon has an objective cause. This effect was demonstrated in behavior descriptions of a mental disorder that was either labeled with the fictional name “depataphy” or left unlabeled. In the present study, we replicated this effect (N = 110) and added new conditions in order to assess whether another linguistic form, a metaphor, could cause the same effect. A separate group (N = 119) evaluated two conditions wherein, instead of a verbal label, we informed participants that the internal state of the person behaving abnormally can be compared to some other event (e.g., a fire). One condition (the so-called nonconventional metaphor) emphasized that this comparison is made by the character of the story himself, and the second condition emphasized other people with a similar behavioral disorder (the so-called conventional metaphor). According to our hypothesis, only the conventional metaphor could affect the formation of explanations, because the conventionality would give the metaphor the status of a category name. The hypothesis was partially confirmed: in the condition with a nonconventional metaphor no significant effect was found, and in the condition with a conventional metaphor it was found in the answers to only one question. The results of the study are generally consistent with the interpretation by Giffin and colleagues that judgments are primarily influenced by a category label rather than other linguistic forms.