Infants Born Preterm Demonstrate Impaired Exploration of Their Bodies and Surfaces Throughout the First 2 Years of Life

Abstract

Background: Non-object-oriented exploratory behaviors infants perform with their bodies and surfaces have been proposed to be key precursors of infants' object exploration, early learning, and future cognitive development. Little is known about the developmental trajectories of these behaviors, especially for infants born preterm.

Objective: The purpose of the study was to longitudinally compare non-object-oriented exploratory behaviors performed by full-term and preterm infants.

Design: The study followed 24 full-term and 30 preterm infants (6 with significant brain injury) performing non-object-oriented exploratory behaviors in prone, supine, and sitting from birth through 24 months.

Methods: Infants were observed without objects or direct social interaction for 3 minutes in prone and supine (0 through 9 months) and in sitting (3 through 24 months). Behavioral coding produced data that were analyzed using hierarchical linear modeling. Developmental trajectories of behaviors were compared among full-term infants, preterm infants without significant brain injury, and preterm infants with significant brain injury.

Results: Compared to full-term peers, preterm infants showed poorer postural control (less head lifting in prone), midline behavior (holding the head in midline, holding both hands in midline), hand-to-mouth and visual-motor behaviors against gravity, and more asymmetrical one-handed fisting. Preterm infants performed fewer bouts of non-object-oriented exploratory behaviors, and their behaviors were less variable with fewer combinations.

Limitations: There was a limited sample of infants born preterm with significant brain injury.

Conclusions: Non-object-oriented exploratory behaviors are important for early perceptual-motor development. Key differences were noted in these behaviors for infants born preterm. These differences may lead to impaired reaching, object exploration, and cognition. Early intervention programs should utilize assessments and interventions that target these very early non-object-oriented exploratory behaviors.