Japanese researchers have 'tracked' the way new-born babies move their arms and legs, apparently for no specific reason. These are actually brain 'exercises' to explore the surrounding space.
Whoever’s come into contact with a new-born that’s a few days or weeks old knows that infants move continually, even when they’re asleep, kicking their legs and moving their arms. Until now no one knew the reason for these movements, which seemed involuntary and random. However, a group of Japanese neonatologists and neuroscientists from the University of Tokyo have tried to understand more clearly and have come up with a subtle method.
As illustrated (including in a series of drawings) in the scientific journal PNAS, researchers created a careful record of all the spontaneous movements of 12 new-borns, who were less than 10 days old, and 10 infants around 3 months old – all of whom were healthy. They used a model they developed with hundreds of recorded movements, each one associated with the areas of the brain that govern them, and the stimulations that cause them. In this way, the researchers managed to recreate what happens when a child moves a limb, and to explain the importance of this movement – which is vital for development.
An explanation as to why new-borns move continually
In short, the brain learns a series of stimuli and experiments with different responses until it finds the most appropriate ones. Moving the limbs is therefore an authentic exploration of the surrounding environment (so different from the dark, protected space of the womb), and helps calibrate muscular and spatial responses to stimuli.
And these are not mere repetitions of random, mechanical movements, but successively refined responses, motivated essentially by curiosity and discovery, i.e., the most important functions of the human brain, which is also confirmed by the fact that there is no reward for motivated movement.
Neonatal screening
As well as providing a very credible explanation of the phenomenon, the discovery could also be useful for neonatal screening. In other words, if an infant does not move enough or in one of the many expected ways, abnormalities in the development of the somatosensory system may be detected in time and action may be taken, where possible.
This type of deficit is also typical of certain diseases (e.g., genetic or neurological diseases like cerebral palsy), and a test like the one developed by the Tokyo researchers could help to define the criteria for diagnosis more clearly.
