During the early years, the brain has a staggering number of developmental tasks to accomplish, and environments influence its formation. If the environment is a poor one, final sculpting of neuronal connections will bypass or distort important aspects of development. During these critical periods when the brain is changing rapidly, we may see relatively sudden growth (interspersed with needed regressions, or "rest periods") in a child's ability to perform certain types of mental operations. Since virtually all parts of the brain are active during these years, anything that limits appropriate experiences or sets up undesirable emotional/motivational patterns will have profound and lasting effects.
Networks of connections are forming for social, emotional, and cognitive abilities—with emotional and language interaction from human caregivers the main impetus. Eighteen months is an extremely important juncture when a mental growth spurt opens new windows for conceptual understanding of natural laws governing both human behavior and the physical world. This age is also a turning point in sociability and for organizing the child's senses around movement. Putting normally developing babies on computers for any amount of time is so ridiculous that it hardly bears further comment. In fact, animal studies looking at "augmented sensory experience," or abnormal overstimulation of more than one sense too early in life, have shown it has lasting negative effects on attention and learning. Scientists can't ethically do this type of research on humans, but some parents seem to be trying!
Profound developmental tasks to be mastered include the following seven types of learning that may be distorted by too much electronic stimulation:
"Can a computer cheat at tic-tac-toe?" Yes, it's alive, it cheats, but it doesn't know it's cheating."
Since even older children and adults have trouble sorting out the "humanness" of electronic brains, young children may be profoundly affected by the social and emotional relationship they develop with their machines. Computers must never supplant supportive human environments. In a large study of day care, researchers at 14 universities found that children's intelligence, academic success, and emotional stability were determined primarily by the personal and language interaction they had with adults. Optimally, the brain does its important work in a context of relaxed exploration guided primarily by the child and supported by helpful and emotionally responsive but not overly intrusive adults.
Digi-tykes may be especially at risk if certain types of software induce overactivation of the right hemisphere and concurrent underactivation of the left. In one provocative study, 4-year-old children with greater amounts of left frontal activation displayed more social competence, while children who showed more right activation displayed social withdrawal. Whether computer use will prove to be related to similar electrophysiological changes is an interesting question.