Dexterity and Its Development

Mark L. Latash Pennsylvania State University

In the second quarter of the 20th century, two great physicists, Albert Einstein and Niels Bohr, discussed the basic principles of the physical foundation of our world. Recent progress in theoretical physics, at that time, had led to the formulation of the principle of uncertainty (the Heisenberg principle) according to which there are limits to the accuracy with which one can define position and impulse (the product of mass and velocity) of a particle. In a sense, this principle means that a particle is in a way spread over an area of space, and one can speak only about the probability of finding the particle in a certain point. This principle represented a huge leap from the determinism of the Newtonian classical mechanics. Einstein was very reluctant to accept this idea. He is attributed with saying that God does not play dice with nature. However, the later development in physics has proven that Heisenberg and Bohr were right: God does play dice!

Strong effects of the probabilistic properties of our world are commonly seen only at the level of elementary particles but not in the physics of everyday life. However, one is tempted to ask the following string of questions: Are the basic physical principles equally applicable to movements of inanimate objects and to the functioning of the human brain? Does the brain play dice with nature? How does it come to its wise solutions when it seems to have a virtually infinite number of choices? What does it mean to have a choice? Can one formally separate having a choice from being forced into a unique response? In this chapter, I move through this spectrum of questions, hoping that at the end I will be able to say something smart about whether the brain plays dice with nature.

-277-