Page:Brain Volume 31 Part 3.pdf/2



had long been recognized that the consequences of injury to a peripheral nerve could not be adequately explained on any accepted theory of its structure and function. In 1901, Dr. Head and Mr. Sherren therefore determined to make a systematic examination of the patients attending the London Hospital for some nerve injury. The hospital patient is frequently an admirable subject for sensory experiments; at his best he answers "Yes" and "No" with certainty, and is commendably steady under the fatigue of control experiments. Moreover, the number of patients, who come to the London Hospital for such injuries, is so large that it is possible to eliminate entirely those who are found to be untrustworthy in consequence of misuse of alcohol or other causes.

Most of the main facts of nerve distribution and recovery of sensation can be elicited from a study of hospital patients by means of simple tests requiring no undue expenditure of time. But such patients can tell little or nothing of the nature of their sensations, and the time they are able, or willing, to give is insufficient for elaborate psycho-physical testing.

It soon became obvious that many observed facts would remain inexplicable without experimentation carried out more carefully and for a longer period than was possible with a patient, however willing, whose ultimate object in submitting himself to observation is the cure of his disease. For instance, an examination of the part played by heat- and cold-spots in the return of sensation was impossible under clinical conditions.

It is also unwise to demand any but the simplest introspection from patients, to whatever class they may belong. This side of the investigation was, therefore, almost entirely closed to Mr. Sherren and Dr. Head. From the early days of their research, Dr. Rivers had acted as their guide and counsellor. His interest lay rather in the psycho-physical aspect of the work, and he was impressed with the insecurity of this side of the investigation. Introspection could be made fruitful by the personal experiences of a trained observer only.

Lastly, we were anxious to investigate the functions of deep sensibility. Sherrington [25] had shown that muscular nerves contained a large number of afferent fibres. From the beginning of their research, Head and Sherren had tried to determine the sensibility remaining after complete division of all cutaneous nerves without injury to the muscular branches. But accidental injuries of this kind are excessively