How 9-month-old crawling infants profit from visual-manual rotations in a mental rotation task

Studies show that visual-manual object exploration influences spatial cognition, and specifically mental rotation performance in infancy. The current work with 9-month-old infants investigated which specific exploration procedures (related to crawling experience) support mental rotation performance. In two studies, we examined the effects of two different exploration procedures, manual rotation (Study 1) and haptic scanning (Study 2), on subsequent mental rotation performance. To this end, we constrained infants' exploration possibilities to only one of the respective procedures, and then tested mental rotation performance using a live experimental set-up based on the task used by Moore and Johnson (2008). Results show that, after manual rotation experience with a target object, crawling infants were able to distinguish between exploration objects and their mirror objects, while non-crawling infants were not (Study 1). Infants who were given prior experience with objects through haptic scans (Study 2) did not discriminate between objects, regardless of their crawling experience. Results indicated that a combination of manual rotations and crawling experience are valuable for building up the internal spatial representation of an object.