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Updated: May 22, 2026
Quantifying Learning in Young Infants: Tracking Leg Actions During a Discovery-learning Task
Published on: June 1, 2015
Adaptive actions of young infants in the task of reaching for objects
Nelci Adriana Cicuto Ferreira Rocha1, Ana Carolina de Campos, Fernanda Pereira dos Santos Silva
1Department of Physiotherapy, Neuropediatrics Sector, Federal University of São Carlos, Rua José Riga, 310 Residencial Samambaia CEP: 13565-560, São Carlos, São Paulo, Brazil. acicuto@gmail.com
Insights
Infants adjust their reaching movements based on object properties like size and rigidity. As infants age, their arm control and grasping success improve, showing early adaptation to environmental affordances.
Area of Science:
- Developmental Psychology
- Motor Control
- Infant Motor Development
Background:
- Previous research explored movement adjustments to environmental affordances.
- The impact of specific object properties on early motor adjustments remained understudied.
Purpose of the Study:
- To investigate the combined effect of object size and rigidity on reaching movements in young infants.
- To understand how infants modify their movement strategies based on object affordances.
Main Methods:
- Sixteen typically developing infants were observed at 4, 5, and 6 months of age.
- Infants interacted with four objects varying in size (small/large) and rigidity (soft/rigid).
- Reaching movements, arm control, and grasping success were analyzed.
Main Results:
- Reaching movements became straighter and arm control improved with age.
- Grasping success increased significantly across the observed age range.
- Object size and rigidity collectively influenced movement adjustments, grasping, and timing.
Conclusions:
- Infants demonstrate an ability to modify reaching and grasping strategies based on object properties early in development.
- Early motor development involves adapting movement to the affordances presented by objects.
- Object characteristics like size and rigidity play a crucial role in shaping infant motor behavior.
Abstract:
Although several studies have investigated how movement trajectory and arm/hand configuration are adjusted to environmental affordances, the influence of specific object properties on early adjustments has not been studied. In this study, we aimed to determine the combined effect of object size and rigidity on reaching movements in young infants. Sixteen typically developing infants were assessed at 4, 5, and 6 months of age. The infants were presented with four objects: two soft and two rigid, which were either small or large. The results indicate that with age reaching movements became straighter, the arm control during the final phase was improved, and the grasping success increased. Object size and rigidity collectively influenced the proximal adjustments, grasping, adjustment time, and the number of movement units. The results suggest that early in the infants are able to modify their movement strategies based on object affordances.
