ABSTRACT
The cerebral cortex is a structurally complex system, having a vast number of elementary units, even if consideration is restricted just to its neurons. Besides the huge number of elements is the extreme density of the interconnections among them. Each cortical neuron receives synaptic contacts from, and projects to, thousands of others. Cortical neurons are connected over a range of spatial scales from microns to tens of centimeters, and are likewise organized into groupings at multiple hierarchical levels, from microcolurnns to global systems. Many cortical neurons are also embedded in long-range loops involving subcortical structures. Structural order is achieved within this complexity by cooperative processes at work in the brain. These processes, which are self-organizing, operate at every spatial scale, and include such phenomena as the development of cytoarchitectonic regions and the establishment of topographic maps [1].
