Psychological Work at the Edinburgh Brain Injuries Unit

The psychological work at the Brain Injuries Unit has developed along three principal lines. In the first place, we have given much attention to the study and as§essment of specific patterns of cognitive disability associated with cerebral injury or disease. This work was inspired by urgent practical demands, but has incidentally given rise to some research studies that I shall review briefly at the end of this paper. In the second place, we have explored certain psychological techniques which may have value in neuropsychiatric diagnosis. And, in the third place, we have endeavoured to adapt, where possible, general psychological principles and methods to concrete problems of re-education and resettlement. The work as a whole has been under the general direction of Prof. D. K. Henderson and Mr. Norman Dott, the Directors of the Unit, and undertaken in close association with Dr. A. Paterson. Problems and Methods of Assessment I would like to preface my review of our work with some general remarks on the methods of psychological assessment and theirplace in clinical science. It is not uncommonly supposed that the psychologist is the fortunate possessor of an esoteric tool which in deference to current fashion I shall call the mental test. Now, a mental test is often conceived to measure in a. more or less accurate way some specific ability, aptitude, or trait. It is apt to be regarded as the exclusive property of the psychologist, who alone is held competent to wield and interpret it. An attitude of this kind to psychological work is both unfortunate and misleading. Strictly speaking, nothing psychological is truly measurable, and a so-called mental test is nothing more than a device for eliciting some specific psychological response under controlled conditions of examination. Thus conceived, it is plain that the neurologist who examines his patient for nominal aphasia is conducting a mental test; so also is the psychiatrist who determines a patient's orientation for time or place by means of suitably chosen questions. But in cases of this kind evaluation is very easy because every normal person can be relied on to give the correct response. When we turn to functions such as memory, intelligence, and thought, and the immensely complicated repertoire of habits and skills to which they give rise in the educated individual, it is plain not only that the normal limits of individual variation are very wide but also that the potential directions of breakdown are many and varied. Simple clinical tests are in consequence seldom sufficient in assessing the psychological sequelae of cerebral lesion, and the demand for more highly controlled methods is easy to understand. Hence the appearance on the neurological scene of the academic psychologist. In the early stages of our work I must admit that we laboured under a certain sense of false security engendered by the admitted success of standardized test techniques in assessing normal intellectual capacity. In a situation which prima facie would seem to call for the greatest caution, we psychologists showed a certain disposition to rush in where angels-and eminent neurosurgeons-rightly fear to tread. Bitter experience has since taught us to recognize that methods adapted to measure intellectual capacities in children and normal adults can seldom be applied with profit in assessing the disabilities of the neurological patient. We now appreciate that a mental test, to have genuine practical value, must be 'based on intimate and thorough clinical observation. My colleague Dr. Andrew Paterson has issued a timely warning in urging that premature stereotyping of methods of examination may cause us to ignore or undervalue the diverse manifestations of organic