The relation between spatial language comprehension and mental transformation during early childhood.

Mental transformation is the ability to visualize, represent, and manipulate two- and three-dimensional objects. Two common types of mental transformations are rotations and translations. Prior studies show that the production of spatial language as well as the comprehension of specific types of spatial words, such as dimensional adjectives, are related to individual differences in mental transformation in early childhood. The present study aims to unpack this prior research by examining whether the relation is motivated by children's comprehension of overall relational language, or this effect is specific to spatial, quantity and/or other relational words. A total of 117 children aged 48 to 94 months (55 girls) completed 26 items on the Boehm-3 Preschool Test of Basic Concepts (Boehm-3) and 32 items on the Children's Mental Transformation Task (CMTT). The Boehm-3 was used to calculate a relational language comprehension variable and specific variables for spatial and quantity and/or other relational words. Mental transformation items were analyzed based on whether they required a translation or rotation. After controlling for child age, child gender, and parent education, analyses showed that children with greater relational language comprehension scores were more accurate across all mental transformation items. When assessing by type of transformation, spatial language comprehension was positively associated with individual differences in mental rotation but not mental translation. These findings suggest that task demands may influence how children's language knowledge supports their spatial thinking.