Hierarchies in Neurology: A Reappraisal of a Jacksonian Concept

In the late 19th century, John Hughlings Jackson advanced the hypothesis that the central nervous system works by means of hierarchies. Although the theory was highly nuanced and complex, its predominant theme held that damage to nervous tissue that made up the highest system caused the brain to revert to a more primitive mode of operation. If a disease or lesion was followed by a certain loss, the physician should not conclude that the lost ability was resident in the damaged region, but rather that the highest system no longer operated and the remaining brain as a whole was working at a more primitive level. In some formulations of his theory, Jackson correlated the dissolution of nervous system hierarchies with presumed stages of phylogenetic development according to the Darwinian theory of evolution.

In 1985, a group of neurologists and neuroscientists gathered in London to observe the 150th anniversary of Jackson's