Sandplay prompts mental processes

Rhoda Kellogg (1979) stated,

Young children cannot learn faster than their brain growth permits. “Hothouse” efforts to cultivate their minds can be dangerous

…Whether the hand holds a crayon or paintbrush, to mark on a paper, or any instrument that makes a scratch on the earth’s surface, or the fingers simply move over a surface covered with steam, frost, food, sand, or any substance that permits a record of the hand movements to be made, the resulting effects will stimulate new brain activity. Creating something with one’s own hand that is new to see constitutes an everlasting and pleasing new mental stimulus that delights homosapiens everywhere. 

When children’s hands are active and guided under eye control, their minds are being developed meaningfully…Children’s eyes and hands must be active for intelligence to develop… The area of the brain’s cortex used for storing sensory data resulting from manual activities is as great as that for storing sensations from shoulders to feet

… The hands must move and the eyes must see the results of movement in order to stimulate mental processes…