There are plenty of studies on how early childhood education can and will improve brain development:
Intervention Can Help Kids Who Are at Risk
"Through the University of North Carolina’s "Abecedarian Project," Craig Ramey and his colleagues demonstrated that
intensive early intervention could greatly enhance the development of children whose mothers have low income and
education levels. The children in the project were randomly assigned to receive either an intensive 5-year program of
full-day, full-year child care and parent involvement activities beginning in the first few months after the child’s birth, or
to receive only free formula and diapers. After just 3 years, dramatic results were evident: the program children had an
average IQ score of 105, while the control group children averaged only 85. And unlike many programs which began
intervention at age 4, the effects of the program on IQ held over time. The program children were less likely to repeat a
grade in school and demonstrated better achievement in reading and mathematics throughout elementary and high
school. At age 21, the children who participated in the 5-year program still displayed a significant intellectual advantage
over the control children. Clearly this intensive, early intervention had a long-lasting impact on these children’s lives."
This is an excellent slide presentation on the formation of children's brains (it notes that the most critical time for development of the brain is up to 5 years of age):
"Genes and environment interact throughout brain development
Genes form neurons, connections among major brain regions
Environment and experience refines the connections; enhancing some connections while eliminating others"