THE KEY TO BUILDING BETTER BRAINS
Everything we learn comes to the brain through our senses. But the brain has built-in obstacles to sensory information input. It is an amazing organ, but it is not able to process the billions of bits of information that bombard it every second. To deal with the barrage, it is equipped with filters to protect itself from input overload and focus on the data most critical for survival.
How your child’s brain responds to environmental sensory data determines what information gets his attention. Only selected information passes through his lower brain filter (called the reticular activating system, or RAS) to enter his thinking brain.
RAD Learning
There are two essential brain processes and three main brain systems that are keys to building better brains. The processes are patterning and neuroplasticity. The three systems are what I refer to as RAD, which is short for:
R: Reticular activating system (RAS) A: Affective filter in the amygdala D: Dopamine
The Reticular Activating System (RAS)—The Brain’s
Sensory Switchboard
The RAS is the attention-activation switching system located at the
lower back of the brain (brain stem). It receives input from the nerves
that converge into the spinal cord from nerve endings in the arms, legs,
trunk, neck, face, and internal organs. The RAS sets the state of arousal
and vigilance of the rest of the brain. It is the RAS that selectively alerts
brains to changes in their environment that impact their survival—
sounds, sights, and smells that may indicate danger or signal opportuni-
ties to find food, mates, or shelter.
The Amygdala—Where Heart Meets Mind
The sensory information that children receive—the things they see, hear, feel, smell, or touch—stimulates the intake centers of their brains beyond the RAS.
The areas most active when new information first enters the brain are the sensory cortex areas in each lobe of the brain. Each of these regions is specialized to analyze data from just one sense (hearing, touch, taste, vision, and smell). This input is identified and classified by matching it with previously stored similar data. The sight of a lemon, for example, connects with the visual cortex in the occipital lobes. The feel of the lemon is recognized by the somatosensory (touch) centers in the parietal lobes. This sensory data must then pass through the brain’s emotional core, the limbic system, especially the amygdala and hippocampus, where emotional significance is linked to information (sour taste is yummy in lemon sherbet but yucky in unsweetened lemon juice). On receiving sensory data, these emotional filters evaluate its pleasure value. That decision determines if the information is given further access to the higher brain, and if so, where the data will go.
Dopamine—Working to Prime Your Child’s Brain
Dopamine is one of the brain’s most important neurotransmitters. (Some of the other neurotransmitters in the brain include serotonin, tryptophan, acetylcholine, and norepinephrine.) These neurotransmitters are brain chemicals that carry information across the spaces (synapses) that form when one nerve ending connects with another. During the last trimester of fetal development, the brain creates thirty thousand synapses per second for every square centimeter of cortical surface.
The brain releases dopamine when an experience is pleasurable. As a pleasure-seeking organ, the brain also releases dopamine in expectation of rewarding, pleasurable experiences. This has several advantages. Dopamine release increases attentive focus and memory formation. When dopamine is released during enjoyable learning activities, it actually increases children’s capacities to control attention and store long- term memories.
HOW THE BRAIN BUILDS MEMORY
When your child’s brain turns sensory input into memory, she learns. The construction of new memories allows her brain to learn by experience and predict the outcome of her behaviour. Memory is a survival requirement for animals that must learn, store, and recall how they should respond to physical needs and changes in their environment. They reactivate stored memories to recall and predict. Where did they go to find food? What places were dangerous because of predators? Where was the safe cave that provided shelter?
Each time your child remembers something, he is also reactivating a neural network that his brain previously created. When he adds new memories related to information already in brain storage, the neural circuit for that pattern or category of knowledge grows larger as more connections form between nerve cells. In essence, the more information stored in the brain’s networks, the more successfully we respond to our environments. The more we learn, the more information stored in our neural networks, the more likely our brains are to relate to new information—hence, learning promotes learning.
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