Degrees of Automatic Action: Some Psychiatric Applications of Hughlings Jackson's Concept of `Reduction to a More Automatic Condition'.

TIIE doctrine of the reflex constitution of the nervous system-the foundation of Hughlings Jackson's neurological teaching (II, 63, 399)*-has received ample recognition in the study of the more primitive activities of the organism, such as locomotion, but has, by contrast, received practically no recognitioni in the study of that most complex activity, mentation. Failure to regard the highest cerebral centres as a reflex mechanism is utterly contrary to the views of Jackson, who held that the highest centres, while more complex than the lowest, are, like the lowest, subject to the laws of reflex actioin. Thus he wrote (II, 63): ' A manl, physically regarded, is a sensorimotor mechanism. I particularlv wish to insist that the highest centres-physical basis of mind or consciousness-have this kind of constitution, that they represent innumerable different impressions and movements of all parts of the body, although very indirectly, as certainly as that the lumbar enlargement represents comparatively few of a limited region of the body nearly directly. . . . If the doctrine of evolution be true, all nervous centres must be of sensorimotor constitution. A priori, it seems reasonable to suppose that, if the highest centres have the same composition as the lower, being, like the lower, made up of cells and fibres, thev have also the same constitution. It would be marvellous if, at a certain level, whether we call it one of evolution or not, there were a sudden change into centres of a different kind of constitution.' The puirpose of this paper is to demonstrate some concrete applications of Jackson's views on the reflcx constitution of the highest centres. Specificallv, I shall try to show that certain mental symptoms may be looked upoIn as illustrations of what Jackson called 'reduction to a more automatic condition.' While Jackson insisted that the laws of reflex action apply to mental