The nature of late post-traumatic syndromes has existing under basal conditions, the present study was intrigued many investigators. Numerous reports have extended to investigation of respiratory functions durappeared which blamed the occurrence of symptoms, ing work and strain. This procedure was also likely among other things, on the nature of the injury, the to answer the question whether the frequent complaint brain region affected, the pre-traumatic personality, or of easy fatigability is related to abnormalities of the the desire for compensation. But few of these studies respiratory functions or not. Hence, all the patients made use of objective methods and the evaluation was, were subjected to a standard' task of work, which in usually biased by the examiner's personal opinion. To a subsequent experiment was complicated by physical obviate these shortcomings, an attempt 1 was made to strain. The latter was produced by having the subcompare psychological and physiological functions of ject perform manual work under ischemia of the post-traumatic cases with those of patients suffering working arm, which induces rapid fatigue and pain, from brain disease on the one hand, and from psycho-The amount of work done, muscular tension and neuroses on the other. It was hoped that such a com-changes in heart rate were thus simultaneously reparison would reveal which of the post-traumatic fea-corded together with ventilation and metabolism in tures are related to the presence of brain damage and cases with brain disease, recent head injuries, chronic which to psychoneurotic developments.head cases, and psychoneuroses. It was hoped that In search of objective methods which would sub-the choice of methods as well as the comparison of stantiate the presence of abnormal mental trends, at-various types of patients would contribute to the tention was directed to the use of the Minnesota Multi-understanding of the etiology of post-traumatic synphasic Personality Inventory (8), which in spite of dromes.some shortcomings was considered to constitute the CASE M A T E R i A L best available test for investigation of personality. The intellectual functions were examined by a shortened T h e P°P u l a t i o n s t u d i e d consisted of patients who version of the Wechsler-Bellevue Adult Intelligence were either referred by doctors or sought spontaneously Scale. T h e selection of physiological tests was brought t