But decidedly the most interesting detail about the anaesthesia is that shown by the extreme liability of the eye to stop reflexly on the red or the green light, in the second experiment with the pendulum.  Suppose the eye to be moving from P to P’ (Fig. 5); the anaesthesia, although beginning later than the movement, is present when the eye reaches O, while it is between O and N, that is, during the anaesthetic moment, that the eye is reflexly caught and held by the light.  This proves again that the anaesthesia is not retinal, but it proves very much more; namely, that the retinal stimulation is transmitted to those lower centers which mediate reflex movements, at the very instant during which it is cut off from the higher, conscious centers.  The great frequency with which the eye would stop midway in its movements, both in the second pendulum-experiment and in the repetition of Dodge’s perimeter-test, was very annoying at the time, and the observation cannot be questioned.  The fact of the habitual reflex regulation of voluntary movements is otherwise undisputed.  Exner[24] mentions a variety of similar instances.  Also, with the moving dumb-bell, as has been mentioned, the eye having begun a voluntary sweep would often be caught by the moving image and carried on thereafter reflexly with the pendulum.  These observations hang together, and prove a connection between the retina and the reflex centers even while that between the retina and the conscious centers is cut off.

   [24] Exner, Sigmund, ’Entwurf zu einer physiologischen
   Erklaerung der psychischen Erscheinungen,’ Leipzig und Wien,
   1894, S. 124-129.

But shall we suppose that the ‘connection’ between the retina and the conscious centers is cut off during the central anaesthesia?  All that the facts prove is that the centers are at that time not conscious.  It would be at present an unwarrantable assumption to make, that these centers are therefore disconnected from the retina, at the optic thalami, the superior quadrigeminal bodies, or wheresoever.  On broad psychological grounds the action-theory of Muensterberg[25] has proposed the hypothesis that cerebral centers fail to mediate consciousness not merely when no stimulations are transmitted to them, but rather when the stimulations transmitted are not able to pass through and out.  The stimulation arouses consciousness when it finds a ready discharge.  And indeed, in this particular case, while we have no other grounds for supposing stimulations to the visual centers to be cut off, we do have other grounds for supposing that egress from these cells would be impeded.

   [25] Muensterberg, Hugo, ‘Grundzuege der Psychologie,’ Leipzig,
   1900, S. 525-561.