Pareidolias: complex visual illusions in dementia with Lewy bodies

• DOI: 10.1093/brain/aws126
• Publication Date: 2012-05-31T06:07:03Z
• Authors: Makoto Uchiyama; Yoshiyuki Nishio; Kayoko Yokoi; Kazumi Hirayama; Toru Imamura; Tatsuo Shimomura; Etsuro Mori
• Keywords: Lewy body

Patients rarely experience visual hallucinations while being observed by clinicians. Therefore, instruments to detect directly from patients are needed. Pareidolias, which complex illusions involving ambiguous forms that perceived as meaningful objects, analogous and have the potential be a surrogate indicator of hallucinations. In this study, we explored clinical utility newly developed instrument for evoking pareidolic illusions, Pareidolia test, in with dementia Lewy bodies—one most common causes elderly. Thirty-four bodies, 34 Alzheimer's disease 26 healthy controls were given test. bodies produced much greater number compared those or controls. A receiver operating characteristic analysis demonstrated pareidolias differentiated sensitivity 100% specificity 88%. Full-length figures faces people animals accounted >80% contents pareidolias. Pareidolias who had well did not hallucinations, suggesting do reflect themselves but may susceptibility sub-analysis treated donepzil numbers correlated visuoperceptual abilities former indices delusional misidentifications latter. Arousal attentional deficits mediated abnormal cholinergic mechanisms dysfunctions likely contribute development bodies.