Related Experiment Video

Updated: Jun 10, 2026

Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale
19:15

Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale

Published on: August 25, 2014

[Laterality of upper extremity movements in infancy: observations at 4 and 9 months of age]

Yuka Shiotani1, Shigeyuki Matsuzawa, Hiroko Ikeda

  • 1Research Institute of Science and Technology for Society, Japan Science and Technology Agency (RISTEX-JST), Osaka.

No to Hattatsu = Brain and Development
|July 30, 2010
PubMed

Insights

Infant reaching behavior shows increased object interaction by 9 months. By this age, the lateralization of upper extremity movements, like reaching for toys, becomes apparent.

Area of Science:

  • Developmental psychology
  • Motor development
  • Infant behavior

Context:

  • Observing upper extremity movements in infants aged 4 and 9 months.
  • Utilizing a laboratory setting to record reaching behaviors for various objects.
  • Data collected from 202 infants participating in the Japan Children's Study.

Purpose:

  • To investigate the process of movement lateralization during infancy.
  • To determine the age at which upper extremity movement lateralization emerges.
  • To analyze changes in reaching frequency and hand preference over time.

Summary:

  • Infants significantly increased object reaching frequency from 4 months (40%) to 9 months (98%).
  • While hand preference for balls was unclear at 4 months, reaching for toy cars showed a significant right-hand preference by 9 months (50% right vs. 19% left).
  • These findings suggest that lateralization of upper extremity movements is established by 9 months of age.

Impact:

  • Provides insights into the developmental timeline of motor control and hand preference in infants.
  • Contributes to understanding the emergence of functional asymmetries in early human development.
  • Highlights the importance of age-specific object interaction studies for motor development research.

More Related Videos

An Objective and Child-friendly Assessment of Arm Function by Using a 3-D Sensor07:25

An Objective and Child-friendly Assessment of Arm Function by Using a 3-D Sensor

Published on: February 12, 2018

Quantifying Learning in Young Infants: Tracking Leg Actions During a Discovery-learning Task11:18

Quantifying Learning in Young Infants: Tracking Leg Actions During a Discovery-learning Task

Published on: June 1, 2015

Related Concept Videos

Anatomical Movements00:51

Anatomical Movements

Anatomical movements refer to the various actions or motions that can be performed by the body's joints and muscles. These movements are described using specific terms to provide a standardized way of discussing and understanding the range of motion at different joints.
Here are some common anatomical movements:
Flexion and extension motions are in the sagittal (anterior–posterior) plane of motion. These movements take place at the shoulder, hip, elbow, knee, wrist, metacarpophalangeal,...
Lateralization01:28

Lateralization

Brain lateralization refers to the division of mental processes and functions between the two hemispheres of the brain, a phenomenon that optimizes neural efficiency and underpins complex abilities in humans. This specialization allows each hemisphere to perform tasks where it has a comparative advantage, facilitating more refined cognitive capabilities across different domains.
Changes in the Appendicular Skeleton with Age01:09

Changes in the Appendicular Skeleton with Age

The upper and lower limb initially develops as a small bulge called a limb bud, which appears on the lateral side of the early embryo. The upper limb bud appears near the end of the fourth week of development, with the lower limb bud appearing shortly after.
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...