Summary: A new study reveals that babies’ spontaneous, random movements help the development of the sensorimotor system.
Source: University of Tokyo
Spontaneous, random baby movements help develop sensory-motor systems, according to a new study led by the University of Tokyo.
Detailed motion capture of newborns and infants was combined with a musculoskeletal computer model to enable researchers to analyze communication between muscles and sensations throughout the body.
The researchers found patterns of muscle interaction that developed based on random exploratory behaviors that would allow the babies to make sequential movements as babies later on.
A better understanding of how our sensory-motor system develops can help us gain insight into the origins of human movement and help diagnose developmental disorders earlier.
From birth – and even in the womb – babies begin to kick, fidget, and act seemingly aimlessly or without external stimulus. These are called “spontaneous movements” and researchers believe they have an important role in the development of the sensorimotor system, the ability to control, move and coordinate muscles.
If researchers can better understand these seemingly random movements and how they are involved in early human development, we may be able to identify early indicators of certain developmental disorders, such as cerebral palsy.
Currently, there is limited information about how newborns and infants learn to move. “Previous research on sensorimotor development has focused on kinematic properties, muscle activities that cause movement in a joint or part of the body,” said Project Assistant Professor Hoshinori Kanazawa of the Information Science and Technology Institute.
“However, our work focused on muscle activity and sensory input signals for the whole body. By combining a musculoskeletal model and neuroscientific method, we found that spontaneous movements that seem to have no apparent task or purpose contribute to coordinated sensorimotor development.”
First, the team recorded the joint movements of 12 healthy newborns (less than 10 days old) and 10 toddlers (about three months old) using motion capture technology. They then estimated the infants’ muscle activity and sensory input signals with the help of a whole-body, infant-scale musculoskeletal computer model they created.
Finally, they used computer algorithms to analyze the spatio-temporal (both space and time) aspects of the interaction between input signals and muscle activity.
“We were surprised that during spontaneous locomotion the infants’ movements ‘wander’ and maintain various sensory-motor interactions. We called this phenomenon ‘sensorimotor wandering’,” said Kanazawa.
“It is generally assumed that sensorimotor system development is usually dependent on the occurrence of repeated sensorimotor interactions, so the more you do the same action, the more likely you are to learn and remember it.
“However, our results implied that infants develop their own sensorimotor system based on exploratory behavior or curiosity, thus repeating several actions, not just the same action. In addition, our findings provide a conceptual link between early spontaneous movements and spontaneous neuronal activity. ”
Previous studies in humans and animals have shown that motor behavior (movement) includes a small set of primitive muscle control patterns. These are patterns that are typically task-specific or can be seen in cyclical movements such as walking or lying down.
The results of this latest study support the theory that newborns and young children can acquire sensorimotor modules, i.e. synchronized muscle activities and sensory inputs, through spontaneous whole-body movements without apparent purpose or task.
Even through sensory-motor navigation, the infants showed an increase in coordinated whole-body movements and anticipatory movements. The movements performed by the infant group showed more common patterns and sequential movements compared to the random movements of the newborn group.
Next, Kanazawa wants to look at how sensorimotor navigation affects later development such as walking and reaching, along with more complex behaviors and higher cognitive functions.
“My main background is in infant rehabilitation. My main goal in my research is to understand the mechanisms underlying early motor development and to find information that will help support infant development.”
About this neurodevelopment research news
Author: press office
Source: University of Tokyo
To contact: Press Office – University of Tokyo
Picture: Image courtesy of Kanazawa et al.
Original research: The results will appear in: PNAS