With a few exceptions, the history of neuropsychology is the story of psychological theory translated into practical neurology. It is probably not an exaggeration to say that brain pathology has been of concern to psychology mainly to the extent that philosophy of mind, introspection, and inferences from experiments on normal subjects could be supported or disconfirmed by patterns of function breakdown. On the other hand, neurologists interested in more than case reports and anatomical localization have looked to psychological theory -- behavioral, gestalt, cognitive -- for explanations of clinical findings. Yet, for a long time I have thought this not to be the proper approach to the pathological material. It seemed that a psychology was lurking in the neurological clinic, one waiting to be built up directly on the study of pathological symptoms.
For me, as for others (notably Freud), the problem of aphasia pointed the way to psychological theory. The aphasias are a window into cognitive structure, and the search for a theory that explains the diversity of aphasic disorders leads to a theory that accounts, more generally, for disorders of action and perception. In other words, the aphasias provide the insight that principles underlying language and its disorders are fundamentally the same as those of other cognitive domains. This book is the record of a search for such a theory. In part, it grew out of questions that were raised by Karl Pribram in a gracious review of my book Mind, Brain and Consciousness and the obvious need that he exposed for me to delve more deeply into disorders of action and perception. In many ways, this collection is a response to that review, an effort to document and to extend the theory outlined in that monograph.
The opportunity to begin the documentation was provided by an NIH research grant -- not of course for the study that was funded, but for the free time to do other things -- and the hospitality of George Miller during a year at Rockefeller. It was during this year that I realized that cognitive science, for all the euphoria, has little to offer to clinical study, although it does provide a good illustration of my opening contention.