90 THE POPULAR SCIENCE MONTHLY 



morning, and the memory gaps are filled out by the patient, often with 

 those occurrences which the patient would like to have had occurred. 

 In this way such delusions may be considered to be allied to the idea- 

 tional type, those of wish fulfilment which were described above. 



An amnesia may lead to a delusion or false belief regarding the 

 locality of a given place. An excellent example of this has been de- 

 scribed by Alzheimer. A Eussian who had emigrated, and located in 

 Frankfurt, was taken to a hospital, where he insisted that he was in 

 Eussia. He could not recall any of the incidents of his removal from 

 Eussia and the period of time between his emigration from Eussia until 

 his admission to the hospital was lost from memory. The most natural 

 conclusion for the patient under these circumstances was that he con- 

 tinued to be in Eussia. Such a disorientation may be considered to be a 

 delusion due to the lack of recognition of dissimilarities. 



Kraepelin cites a somewhat similar case, due, however, to a different 

 kind of memory defect, which was described by Ganser. This patient 

 was a boy who had been admitted to the Munich psychiatric hospital 

 who insisted that he was in Vienna. He also believed that he had been 

 asked to join a company for the development of the Sahara Desert, that 

 he had been in London to consult with others regarding this, and had 

 just returned to Vienna in a balloon. The whole story was bizarre and 

 apparently without reason, until it was subsequently learned that the 

 patient had borrowed practically the whole system of ideas from a novel 

 which he had read some time previously. He had forgotten the fact 

 that he had read the book, but he remembered the incidents, and since 

 the incidents could not be given their proper setting he assumed that 

 they had happened to him. In this case the defect of memory was a 

 defect in the sense that previous occurrences were not properly located 

 as to personality. The special incidents were suitably remembered, but 

 the reference of them was erroneous. 



Closely associated in character with the delusions which have just 

 been described are others which the French call " deja vu " and " deja 

 entendu." These are conditions in which the individual experiencing 

 them believes that he has had similar experiences in the past. In a 

 perfectly new situation, in a place which he has never before visited, 

 a person believes that he has been a visitor there at some previous time. 

 Or words which are read in the newspaper or words that are heard are 

 believed to be exactly the same as others which he has experienced in 

 the past, not only with respect to the individual words or their com- 

 bination, but also with respect to their context and their meaning as 

 applied to him. These feelings of having already experienced such 

 situations are frequently due to memory defects. But in these cases the 

 memory defects are of quite a different character from those in the cases 

 which have previously been described. In the condition of "deja vu" 



