Our everyday view of the world may not necessarily be the most comprehensive one. In this regard neuropathologists should temper opinions based on a limited representation of reality. Microscopy freezes in time a two-dimensional representation of a minute histological process. One must acquire knowledge of the physiology of the lesion before reaching a multidimensional diagnosis. In the case of mental disorders, the modular organisation of the cortex may offer some clues to underlying aetiology. It is tissue, rather than individual cells, that provides for the phenomena of perceptual binding and gamma frequencies. It is the continuous re-entry of excitation into neuronal networks that provides for selective attention. The basis for language and its semantic content resides in the conjoint activation of topographically diverse brain regions. This book is designed to focus on the lowest hierarchical element within the modular organisation of the brain: the cell minicolumn. The minicolumn is a self-contained ecosystem of neurons and their connections that repeats itself throughout the extent of the neocortex. Although a few neuroanatomists at the turn of the century called attention to the vertical arrangement of the cortex, Vernon Mountcastle provided physiological proof in the 1950's for its existence and its role in perception.