The Japanese journal of neuropsychology

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ArticleTitle	The mechanism of reduplication phenomena of the electronic devices functions:A new symptom of delusional misidentification syndromes
Language	J
AuthorList	Yuki Takakura¹⁾²⁾, Mika Otsuki³⁾, Yoshitsugu Nakagawa⁴⁾, Naoko Takeuchi⁵⁾, Toshihide Sugimura⁶⁾
Affiliation	¹⁾Department of Rehabilitation, Sapporo Shuyukai Hospital ²⁾Graduate School of Health Sciences, Hokkaido University ³⁾Faculty of Health Sciences, Hokkaido University ⁴⁾Department of Communication Disorders, School of Psychological Science, Health Sciences University of Hokkaido ⁵⁾Department of Rehabilitation, Dohtoh Neurosurgical Hospital ⁶⁾Department of Neurosurgery, Dohtoh Neurosurgical Hospital
Publication	Japanese Journal of Neuropsychology: 31 (1), 56-69, 2015
Received	Jan 30, 2014
Accepted	Jun 20, 2014
Abstract	The present study reports a patient with a specific form of delusional misidentification symptoms that developed after a neurosurgical clipping for ruptured anterior communicating artery aneurysm. The patient was a 53-year-old right-handed male native speaker of Japanese, and employed as a general director for a cooperative. Brain MRI (Magnetic Resonance Imaging) demonstrated the restricted lesion in the basal forebrain, and bilateral ventral prefrontal cortex. Standardized examinations of language, intelligence, and frontal lobe function revealed the patient's performances were within normal range. Nonetheless, he presented significant impairment of memory which was accompanied with spontaneous confabulation. Moreover, he clearly described his very strange beliefs including that "this electric razor has the mobile phone functions". We handed to him a new razor, however he made the same claim on a new one two days later. The logical structure of his misidentification, such as "reduplication of functions", was similar to that of reduplicative paramnesia. However, his misidentification has two differences from those heretofore reported. First, his misidentification was extended beyond the proper subjects over the object such as a new razor. Second, impalpable "mobile phone functions" were reduplicated. Therefore, we propose "the reduplication phenomena of the electronic devices functions" placing in DMS (Delusional Misidentification Syndromes) as one of the new symptoms. In addition, we discuss his delusional misidentification symptoms from the view point of neurobiological and psychosocial factors. From the perspective of neurobiology, we suggest the possibility that failure of an appropriate "familiarity" and "recollection" caused by the damage to the basolateral circuit was implicated in the development of his symptoms. From the psychosocial standpoint, his strong desire to "make a call" induced by the context of the hospital environment might have played a crucial role in his delusional beliefs. Finally, the findings show that a mobile phone should have an extremely high emotional valence as in the case of familiar persons and places. This fact indicates that the increase of mobile phone users may cause the increase of misidentification symptom implicated in mobile phone.
Keywords	delusional misidentification syndromes, reduplicative paramnesia, familiarity, recollection, mobile phone