Scientists have found that the rate of synapse formation peaks around age 4, resulting in synaptic density levels that are 50% higher than adults, indicating increased brain activity. This increased neural activity suggests that this might be an optimal time for cognitive growth and development, and this information is a major reason educators have become interested in brain development. (Eggen, 2001)
The human brain has between 100 and 200 billion neurons (nerve cells), and connections between them, called synapses. (Jensen, 1998) Information flows in one direction only; going from the cell body down the axon to the synapse. (Jensen, 1998) How neurons make connections is illustrated in Figure 1.
(figure available in print form)
Research on brain development points to three major findings: (1) rapid brain growth occurs during early stages of development, (2) rapid brain growth results in critical periods of development for central processes like language and perception, and (3) enriched environments can result in increased brain growth and development. (Bruer, 1999) These three findings support the need for brain-based instruction, especially in the early grades.
Brain-based, or learner-centered, instruction is grounded in constructivism, and the characteristics of learner-centered teaching grow directly out of this view of learning. (Eggen, 2001) Constructivists believe that learners construct their own understanding, that new learning exists in the context of prior understanding, that learning is enhanced by social activity, and that authentic tasks promote learning. (Eggen, 2001) Types of learner-centered instruction include (a) discovery learning, (b) problem-based inquiry, (c) discussions, and (d) cooperative learning.
Learner-centered instruction, or any successful type of instruction, cannot occur in a non-supportive classroom environment. Productive learning environments are safe, orderly, and learning focused. Learner-centered instruction requires students to feel free to offer conclusions, conjectures, and evidence without fear of criticism or embarrassment. (Eggen, 2001) Modeling these behaviors and insuring a safe environment are the responsibility of the teacher, especially of students who may not be familiar with learner-centered instruction.
Rapid brain growth in the early stages of development via a stimulating classroom environment that reinforces the language and perception processes should not conjure images of chaos and haphazard incentive. A truly stimulating classroom environment offers reinforcers to instruction. Buttressing the development of the young brain, the classroom must first and foremost reinforce of language and perception.