EDITOR: Monday’s article ably explores the problem of kindergarten unreadiness affecting many local children (“Learning lag still persists”). An important piece of this puzzle, though, is all but overlooked. While it’s true that 90 percent of brain growth occurs before age 5, 80 percent of brain growth occurs before age 3. In other words, if we wait until preschool to help children learn, we’ve already missed a critical period of neurodevelopment.

The human brain grows most rapidly from late pregnancy through the first year of life. New neural connections are made at a dizzying pace. Those that are used most often are strengthened, while those that aren’t eventually fade away. A child who is exposed to positive experiences during this critical period will be much better prepared to learn in preschool and beyond.

We as a community can promote optimal brain development by supporting programs that strengthen families, encourage positive parenting, eliminate violence and hunger in our homes and neighborhoods and provide evidence-based home visits to pregnant women in need of extra help — programs like the Nurse Family Partnership and Healthy Families America.

Every child should have a high-quality preschool experience. School readiness starts much earlier than that, though. It begins in the womb.

DR. MARK SLOAN

Santa Rosa