Three principles of brain function and structure.

A large part of the presently available data in the physiology and anatomy of the nervous system is found to be consistent with three comparatively simple principles. Phrased in the terminology introduced in the paper, the first of these expresses the assumption of specificity of neuron response, the second states the biological equivalent of a maximum principle believed to govern the formation and modication of interneuronal connectivity, and the third describes the probable role of genetically determined gross anatomy in securing the groundwork for developing neurospecificity. A number of remarks are included, and an extensive discussion of the evidence behind the principles.