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Differences between late preterm and full-term infants: comparing effects of a short bout of practice on early
Daniele de Almeida Soares1, Andréa Baraldi Cunha2, Eloisa Tudella2
1Department of Physical Therapy, Neuropediatrics Section, Federal University of São Carlos (UFSCar), Rod Washington Luis, km 235, 13565-905 São Carlos, SP, Brazil; Physical Therapy, Center of Biological and Health Sciences, Federal University of Mato Grosso do Sul (UFMS), Postal Box 549, 79070900 Campo Grande, MS, Brazil.
Insights
Late preterm infants show differences in reaching skills at onset compared to full-term infants. While practice helps, late preterm infants may benefit less from this experience for refined manual tasks.
Area of Science:
- Developmental neuroscience
- Motor control and learning
Background:
- Goal-directed reaching emerges early in infancy.
- Understanding developmental differences in reaching onset is crucial for early intervention.
Purpose of the Study:
- To compare reaching behavior in late preterm and full-term infants at the onset of goal-directed reaching.
- To investigate the effects of a short practice bout on reaching in these two groups.
Main Methods:
- Infants (12 late preterm, 12 full-term) were assessed before and after a brief reaching practice session.
- Reaching behavior was analyzed for proximal adjustments, hand posture, and grasping.
- Practice involved toy-oriented reaching activities guided by a physical therapist.
Main Results:
- At pre-test, late preterm infants exhibited less proximal adjustment range and more reaches without grasping.
- Post-practice, late preterm infants showed increased motor variability but less exploration of grasping outcomes.
- Differences in reaching and gross motor behavior are evident at the onset of reaching.
Conclusions:
- Significant differences in reaching behavior exist between late preterm and full-term infants at the onset of goal-directed reaching.
- While practice improved perception-action coupling in late preterm infants, they appeared less adept at benefiting from the experience for refined manual tasks compared to full-term infants.
Abstract:
This study compared the effects of a short bout of practice on reaching behavior between late preterm and full-term infants at the onset of goal-directed reaching. Twelve late preterm infants and twelve full-term infants received reaching practice based on a serial schedule. Late preterm and full-term infants were assessed in 3.3±1.4 and 2.6±1.0 days after the onset of goal-directed reaching in two measures in a single day: immediately before practice (pre-test) and immediately after practice (post-test). During the assessments, the infants were placed in a baby chair and a rubber toy was presented at their midline within reaching distance for 2 min. Between assessments, the infants received practice of toy-oriented reaching in 3 activities repeated for approximately 4 min. The activities were elicited in a pre-established serial sequence and were applied by a physical therapist. During the pre-test, late preterm infants presented lower range of proximal adjustments, greater proportion of reaches with semi-open hand, and greater proportion of reaches without grasping than the full-term infants. During the post-test, late preterm infants presented greater motor variability of proximal adjustments, but explored and selected distal control and grasping outcomes less compared to the full-term group. Differences in reaching and gross motor behavior between late preterm and full-term infants can be found at the age of reaching onset. Practice provided new opportunities for late preterm infants to improve perception-action coupling to reach; however, relative to full-terms, they seemed less advanced in benefiting from the experience for more refined manual tasks.
