ON THE FUNCTIONS OF THE CEREBRUM 343 



time-related manner. Thus, in certain pathological states of the 

 cerebrum, not only may the clock of cerebral activity be put 

 back, but the subject may reproduce in exact detail lengthy 

 portions of former experience, and, stranger still, may start an 

 entirely new time-related psychic life from the point of former 

 experience to which he has returned. He may then, as if nothing 

 had happened, return to the normal point of cerebral activity 

 and recommence his ordinary time-related psychic life, with com- 

 plete obliteration, as far as his conscious knowledge is concerned, 

 of the experiences he has passed through whilst in the abnormal 

 psychic state. It is possible, then, for a person to live two or 

 more psychic lives, of which only one is normal, and in his normal 

 waking state to be entirely unaware of the existence, apart from 

 periods of time for which he cannot account, of his other, or 

 numerous, " sub-egos." Interesting cases of " multiple person- 

 ality " which might seem incredible had they not been studied and 

 recorded by competent and entirely trustworthy observers, have 

 recently been published by Morton Prince and by Albert Wilson. 

 Three less important cases have also been published by Lemaitre. 



Such cases differ somewhat from good examples of systematised 

 delusional insanity, which are, however, of interest in this con- 

 nection. In the latter the personality is altered, but this altera- 

 tion is due, in the developed state, to the permanently abnormal 

 prominence of certain time -related portions of what should be 

 part of the subconscious content of mind. These particular time- 

 related experiences serve as a basis on which develops a continually 

 increasing aggregation of abnormal psychic units. In other words, 

 in place of the normal gradually changing personality, a certain 

 former personality remains as a permanent basis on which is built 

 up a continually increasing abnormal psychic edifice. In such 

 cases, when they become " chronic," it is probable that the greater 

 part of the available psychic content consists of symbolic verbal 

 groupings which have become relatively stable through frequent 

 repetition ; and that the processes of cerebral association required 

 for the reintegration of the former percepts and concepts which 

 these verbal groupings symbolise, and for the revival of old sensori- 

 memorial images, are markedly reduced. These symbo^c verbal 

 groupings continue throughoat the life of the sufferer to entirely 

 dominate what would otherwise be relatively normal processes of 

 immediate cerebral activity, and in this, in effect though greater 



