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Utility of the pareidolia test in mild cognitive impairment with Lewy bodies and Alzheimer’s disease

Lookup NU author(s): Dr Calum Hamilton, Professor Fiona MatthewsORCiD, Dr Louise Allan, Sally Barker, Dr Joanna Ciafone, Dr Paul Donaghy, Dr Rory Durcan, Dr Michael FirbankORCiD, Dr Sarah Lawley, Professor John O'Brien, Dr Gemma RobertsORCiD, Professor John-Paul TaylorORCiD, Professor Alan ThomasORCiD



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


Objectives Previous research has identified that dementia with Lewy bodies (DLB) has abnormal pareidolic responses which are associated with severity of visual hallucinations (VH), and the pareidolia test accurately classifies DLB with VH. We aimed to assess whether these findings would also be evident at the earlier stage of mild cognitive impairment (MCI) with Lewy bodies (MCI-LB) in comparison to MCI due to AD (MCI-AD) and cognitively healthy comparators. Methods One-hundred and thirty-seven subjects were assessed prospectively in a longitudinal study with a mean follow-up of 1.2 years (max = 3.7): 63 MCI-LB (22% with VH) and 40 MCI-AD according to current research diagnostic criteria, and 34 healthy comparators. The pareidolia test was administered annually as a repeated measure. Results Probable MCI-LB had an estimated pareidolia rate 1.2-6.7 times higher than MCI-AD. Pareidolia rates were not associated with concurrent VH, but had a weak association with total score on the North East Visual Hallucinations Inventory. The pareidolia test was not an accurate classifier of either MCI-LB (AUC = 0.61), or VH (AUC = 0.56). There was poor sensitivity when differentiating MCI-LB from controls (41%) or MCI-AD (27%), though specificity was better (91 and 89%, respectively). Conclusions Whilst pareidolic responses are specifically more frequent in MCI-LB than MCI-AD, sensitivity of the pareidolia test is poorer than in DLB, with fewer patients manifesting VH at the earlier MCI stage. However, the high specificity and ease of use may make it useful in specialist clinics where imaging biomarkers are not available

Publication metadata

Author(s): Hamilton CA, Matthews FE, Allan LM, Barker S, Ciafone J, Donaghy PC, Durcan R, Firbank MJ, Lawley S, O'Brien JT, Roberts G, Taylor JP, Thomas AJ

Publication type: Article

Publication status: Published

Journal: International Journal of Geriatric Psychiatry

Year: 2021

Volume: 36

Issue: 9

Pages: 1407-1414

Print publication date: 01/09/2021

Online publication date: 27/03/2021

Acceptance date: 21/03/2021

Date deposited: 22/03/2021

ISSN (print): 0885-6230

ISSN (electronic): 1099-1166

Publisher: Wiley


DOI: 10.1002/gps.5546


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