title: The Pareidolia Test: A Simple Neuropsychological Test Measuring Visual Hallucination-Like Illusions.
abstract: Visual hallucinations are a core clinical feature of dementia with Lewy bodies (DLB), and this symptom is important in the differential diagnosis and prediction of treatment response. The pareidolia test is a tool that evokes visual hallucination-like illusions, and these illusions may be a surrogate marker of visual hallucinations in DLB. We created a simplified version of the pareidolia test and examined its validity and reliability to establish the clinical utility of this test.
  
  
  
  The pareidolia test was administered to 52 patients with DLB, 52 patients with Alzheimer's disease (AD) and 20 healthy controls (HCs). We assessed the test-retest/inter-rater reliability using the intra-class correlation coefficient (ICC) and the concurrent validity using the Neuropsychiatric Inventory (NPI) hallucinations score as a reference. A receiver operating characteristic (ROC) analysis was used to evaluate the sensitivity and specificity of the pareidolia test to differentiate DLB from AD and HCs.
  
  
  
  The pareidolia test required approximately 15 minutes to administer, exhibited good test-retest/inter-rater reliability (ICC of 0.82), and moderately correlated with the NPI hallucinations score (rs = 0.42). Using an optimal cut-off score set according to the ROC analysis, and the pareidolia test differentiated DLB from AD with a sensitivity of 81% and a specificity of 92%.
  
  
  
  Our study suggests that the simplified version of the pareidolia test is a valid and reliable surrogate marker of visual hallucinations in DLB.
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Mamiya
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Nishio
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Watanabe
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.|Department of Occupational Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Yokoi
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.|Department of Speech, Language and Hearing Sciences, Niigata University of Health and Welfare, Niigata, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Uchiyama
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Baba
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Iizuka
authors.affiliation: Department of Neurology, South Miyagi Medical Center, Ohgawara, Japan.
authors.forename: Shigenori
authors.initials: S
authors.lastname: Kanno
authors.affiliation: Department of Neuropsychiatry, Kochi Medical School, Nangoku, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Kamimura
authors.affiliation: Department of Psychiatry, Osaka University School of Medicine, Suita, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kazui
authors.affiliation: Department of Neuropsychiatry, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Hashimoto
authors.affiliation: Department of Neuropsychiatry, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Ikeda
authors.affiliation: Department of Rehabilitation Medicine, Akita Prefectural Center of Rehabilitation and Psychiatric Medicine, Daisen, Japan.
authors.forename: Chieko
authors.initials: C
authors.lastname: Takeshita
authors.affiliation: Department of Rehabilitation Medicine, Akita Prefectural Center of Rehabilitation and Psychiatric Medicine, Daisen, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Shimomura
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Etsuro
authors.initials: E
authors.lastname: Mori
mesh_terms: D000368:Aged; D001519:Behavior; D016022:Case-Control Studies; D003704:Dementia / Q000175:diagnosis; D003710:Demography; D005260:Female; D006212:Hallucinations / Q000523:psychology*; D006801:Humans; D007088:Illusions / Q000523:psychology*; D020961:Lewy Body Disease / Q000175:diagnosis; D008297:Male; D009483:Neuropsychological Tests; D012372:ROC Curve; D015203:Reproducibility of Results