Apperception or attention corresponds, as we have seen, to a kind of macula lulea of the maximum of intensity of the thinking activity wandering in the cerebral neurons. The thinking activity continuously ecphorizes the old slumbering associated engrams, strengthens them again, and remodels them for new combinations, or discharges them centri-fugally for actions. At the same time, it is steadily stimulated by means of the activity of the senses, especially with the help of voluntary movements, by the outer world, and works with the latter in suitable alternating relationship. The intensity and extent of the attention and of its field changes constantly in this activity, which corresponds to that of actual thinking.

During dreaming and in the hypnotic state its activity is altered, is obviously inhibited and slowed, but is not on this account necessarily weakened. The phenomenon of dreams and suggestions, being on the one hand highly dissociated, and on the other extremely delicately apperceived, is a puzzling but nevertheless a true one. Extremely delicate apperceptions can actually follow one another very rapidly in certain directions in the hypnotic state. I will not dwell on this point here (see Chapter TV., section 16).

It is well known that illumination of consciousness appears to us subjectively to increase with the intensity of perception; but, as wo have Been, one makes a great mistake if one deduces from this that subjectivism - i.e., consciousness, sensation - are wanting in toto or in part from the unconcentrated or separately concentrated cerebral activities which lie outside the field of perception. As a matter of fact, our other thinking activities are only apparently more or less unconceived during very intense concentrated perception. Its combination with the chief activity of perception, and thus with the reflection of supereon-sciousness, is loosened, and for this reason it appears in the light of the last named to be dim or to disappear entirely. As a rule, association and amnesia go hand in hand. And functional amnesia only means the entire or partial interruption of the reflection of consciousness of various chains of activities.