I fancy that most people who think at all have done a great deal of their thinking in the first fourteen years.
The most exciting periods of literature have always been those when the critics were great.
Every age fraught with discord and danger seems to spawn a leader meant only for that age, a political giant whose absence, in retrospect, seems inconceivable when the history of that age is written.
Truly, learning appears to be a reverse geometric progression with experiences at one hour, one day, one month or one year dramatically more influential and formative than later experiences. As has often been quoted, 85% of brain development takes place by age 3, and yet we spend only 4% of our educational dollars by that point.
As we know all too well, our early years are formative in ways it can takes us a lifetime to grasp. Those years leave deep marks; in that way, the stakes of childhood are inherently very high.
The first six years of a child's life, it is like a tape recorder is on. Everything it sees, smells, touches, experiences in any way, whatever it hears, is being downloaded into the brain before the consciousness of the child is even made apparent.
In the early Sixties, having begun to describe the physiology of cells in the adult cat visual cortex, David Hubel and I decided to investigate how the highly specific response properties of cortical cells emerged during postnatal development.
The brain, which is plastic when young, must be exposed to certain sights early in life, or it will remain blind to those sights forever.
The human brain is by no means fully formed at birth. It continues to shape itself through life, with the most intense growth occurring during childhood.
The idea of critical windows extends beyond just vision, of course: almost every system in the brain has a critical window when it needs to experience certain stimuli, or it won't get wired up properly. The most obvious example is language: if you don't learn a language early on, it's nigh impossible to become truly fluent.
Children raised in families at the high end of the socioeconomic scale are more likely to be exposed to a stimulating environment and set upon an advantageous path in life with respect to health, cognitive development and social skills. If the brain does not receive the requisite environmental stimulation at certain critical periods, the window of opportunity closes and development fails to occur.
