The development of physiological psychology in recent years has indeed shown the way to such a wider theory, which furnishes the physiological accompaniment also for those experiences of attention and vividness which form the weakness of associationism. This new development has come up with the growing insight that the brain's mental functions are related not only to the sensory impressions, but at the same time to the motor expressions. The older view, still prevalent to-day in popular writings, made the brain the reservoir of physical stimuli, which come from the sense organs to the cortex of the brain hemispheres. There the perceptions arose and through associative interplay the memory pictures and the ideas of action and the feelings arose, and the whole inner life was thus bound up with the processes in these sensorial spheres. When the mind had done its work, finally an impulse was sent to some motor apparatus in the brain which then sent off the impulse to some acting muscles. That whole motor part was thus a kind of appendix to the brain process. The psychical life had nothing to do with it but to give the command for its action. The process in the motor part thus began when the mental proceeding was completed. But it became clear that this view was only the outgrowth of the strong interest which physiology took in the sense processes. If a neutral fair account of the brain actions is attempted, there can hardly be doubt that this whole sensorial view of the brain is only half of the story and that the motor half has exactly the same right to consideration. The cortex of the brain, the functions of which are accompanied by mental processes, is always and everywhere not only the recipient of sensory stimuli but at the same time the starting point of motor impulses. That which is centripetal, leading to the cortex, is therefore not more important for the central process than that which is centrifugal, leading from the cortex. The cortex is the apparatus of transmission between the incoming and the outgoing currents, between the excitements which run to the brain and the discharges which go from the brain, and the mental accompaniments are thus accompaniments of these transmission processes. If the channels of discharge are closed and the transmission is thus impossible, a blockade must result at the central station and the accompanying mental processes must be entirely different from those which happen there when the channels of discharge are wide open. Here too all the special theories are still in the midst of tumultuous discord. Yet this new emphasis on the motor side of the psychical process seems to influence modern psychology more and more.