Infants Born Preterm Demonstrate Impaired Object Exploration Behaviors Throughout Infancy and Toddlerhood

Michele A. Lobo; Elena Kokkoni; Andrea Baraldi Cunha; James Cole Galloway

doi:10.2522/ptj.20130584

Figures

Figure 1.

Assessment of infants' behaviors in the supine position through 6 months (A) and in the sitting position after 6 months (B) as they explored the same 7 objects (C) on repeated occasions through 2 years of age. The objects varied along a range of characteristics, including size, shape, texture, and sound-making ability.

Figure 2.

(A and C) Overall holding time (A) and number of bouts of behavior (C) were similar among groups. (B) Bilateral holding time was similar among groups when it occurred, although it was significantly more common for infants born preterm with significant brain injury (PTBI) not to exhibit any bilateral holding. (D) Infants born preterm spent less time exploring objects in the first 6 months. (E) Infants born preterm also had decreased performance of individual behaviors in the first 6 months. (F) Infants born PTBI had decreased performance of combination behaviors throughout the study. FT=full-term, PT no BI=preterm without significant brain injury.

Figure 4.

Infants born preterm showed differences from infants born full-term (FT) in the ability to match their behavioral performances to the properties of objects. Infants born preterm had delays in or the absence of this ability across multiple behaviors. Differences were most pronounced for infants born preterm with significant brain injury (PTBI). Cells shaded in gray represent visits during which increased behavioral performance was observed for objects with properties expected to elicit more of a behavior; dark gray cells represent significant differences (P≤.006), and light gray cells represent trends for differences (P≤.01). White cells represent visits during which infants exhibited the behavior similarly with all objects regardless of their properties. See Table 2 for details on the properties expected to elicit each behavior and eTable 3 for supporting statistical data. PT no BI=preterm without significant brain injury.

Figure 3.

(A) Infants born preterm touched their bodies less with objects than did infants born full-term (FT) in the first 6 months. (B and C) Even though groups spent similar amounts of time looking at objects overall (B), infants born preterm spent less time looking at objects while exhibiting other actions on them (visual-haptic multimodal exploration) toward the latter part of the study (C). (D) Infants born preterm with significant brain injury (PTBI) squeezed objects less than did infants in the other groups throughout the first year. (E) Infants born preterm without significant brain injury (PT no BI) had a delay in their peak throwing behavior, whereas infants born PTBI exhibited throwing less often overall and did not reach a peak similar to those reached by infants born FT and infants born PT no BI. (F) There were no significant differences in banging behavior, and similar trajectories were observed for infants born PT no BI (who had a delay in their peak banging behavior) and infants born PTBI (who had lower levels of banging behavior throughout most of the study and never reached the same peak levels of performance as the other groups). (G and H) There were trends for less cyclical movement (G) and fingering (H) in infants born PTBI than in infants born FT and infants born PT no BI. (I) No differences were observed among the groups for manipulation, yet the trajectories suggested that the groups may have been headed along different paths for this behavior.

Tables

Table 1.

Demographic Information About Participants^{^a}

↵^a Values are reported as numbers (percentages), unless otherwise indicated. FT=born full-term, PT no BI=preterm without significant brain injury, PTBI=preterm with significant brain injury.
^b Values are reported as means (standard deviations).

Table 2.

Groupings for Object Analyses

Supplementary Data

eTables

Files in this Data Supplement:

eTables - This data supplement contains the following three eTables:
- eTable 1. Model-Estimated Intercepts and Standard Deviations for Infants Born at Various Terms
- eTable 2. Raw Data Means and Standard Errors of the Mean (SEM) for Each Behavior Over Time for Infants Born at Various Terms
- eTable 3. Analyses of Whether Infants Born at Various Terms Exhibited Behaviors Differently With Objects Expected to Elicit Different Levels of Behavior