This is the third part in a four-part blog series.
Read Your Baby's Brain, Part 1: Nurture is as Important as Nature
Read Your Baby's Brain, Part 2: Environmental Influences
Technology, such as Magnetic Resonance Imaging (MRIs), Computerized Tomography Scans (CT Scans) and Positive Emission Tomography (PET Scans), now offer the hard data indicating that experience and environment can change brain development. Brain formation is dependent on brain activity, and because the developing brain is plastic, each and every early childhood experience stimulates, both positively and negatively, its neural connections. Because the brain is highly efficient, it actually dumps neurons that are not being used while strengthening those that are used consistently. This process is called synaptic pruning, and makes it possible for your child to develop correctly. Though synaptic pruning extends through a normal lifetime, it is the most active during early childhood.
There are windows of opportunity when your child's brain is highly susceptible to environmental experiences. During the ages of 0 and 10, your child's brain forms trillions of connections, many of which will be discarded throughout your child's life, as the brain eliminates connections that are seldom or never used. Your child will preserve only those connections that are reinforced through heightened experience. Further, those connections, not stimulated by mental and physical experiences, are discarded or pruned away. It is those mental and physical sensory experiences, by themselves, that establish the critical windows of opportunity in your child's evolving brain. When your child repeats an experience, it establishes a track in his/her brain and if that experience is repeated consistently, the synaptic lesson will not be reversed. If these critical times for learning are missed, they may never be recovered.
For example, if your child has a hearing problem in the first few years of life that goes unrecognized or untreated, then he/she is tracking sound, rhythm, grammar, phonemes and language usage incorrectly. Perhaps sound is muffled or missing the rhythm and intonation of your particular language. Thus, when hearing is corrected, your child will still retain the incorrect rhythm or intonation in his/her speech. And yet, if a speech pathologist is retained early enough, he/she may be able to remediate such a speech disorder.
Additionally, the important window specifically for language acquisition begins to shut down by the age of 5. Children can learn many languages simply by being exposed to them during the language window of opportunity, and they can learn those languages simultaneously. However, if your child is introduced to and acquires a new language at the onset of adolescence, then that language will be spoken with a foreign accent because your child did not track that language during the optimal window for language acquisition.
These critical periods impact all of learning, including visual development, social/emotional development, intellectual development, sensory and motor development, musical ability and so on.
Coming up in the final installation of this blog series, we'll discuss how parents are the ultimate gene therapists.