Association, agnosia, and intellect

“O the mind, mind has mountains; cliffs of fall, Frightful, sheer, no-man-fathomed.”

The importance of the anatomical basis of the simpler motor and sensory functions of the central nervous system, and their disorders, has been recognized for over a century (Brown-Séquard, 1855). But that more complex intellectual functions and their disorders should also have a relevant anatomical substrate is only slowly coming into recognition. Indeed, a still-fashionable theory of mental function, originating in Vienna towards the end of the last century, regards the study of brain structure as unnecessary and beneath contempt—for all that its founder began as a neuro-anatomist.