Abstract

To study pareidolias, or perceived meaningful objects in a meaningless stimulus, in patients across the Lewy body (LB) disease spectrum, where most do not report hallucinations or delusions.We studied illusory responses on the Noise Pareidolia Task in 300 participants [38 cognitively-impaired LB, 65 cognitively-unimpaired LB, 51 Alzheimer's disease-spectrum (AD-s), 146 Controls]. Pairwise between-group comparisons examined how diagnosis impacts the number of illusory responses. Ordinal regression analysis compared the number of illusory responses across diagnosis groups, adjusting for age, sex, and education. Analyses were repeated after removing participants with reported hallucinations or delusions.Cognitively-impaired LB participants were 12.3, 4.9, and 4.6 times more likely than Control, cognitively-unimpaired LB, and AD-s participants, respectively, to endorse illusory responses. After adjusting for age, sex and education, the probability of endorsing one or more illusory response was 61% in the cognitively-impaired LB group, compared to 26% in AD-s, 25% in cognitively-unimpaired LB, and 12% in Control participants. All results were similar after repeated analysis only in participants without hallucinations or delusions. In LB without hallucinations or delusions, 52% with mild cognitive impairment and 66.7% with dementia endorsed at least one illusory response.We found illusory responses are common in cognitively impaired LB patients, including those without any reported psychosis. Our data suggest that, prior to the onset of hallucinations and delusions, the Noise Pareidolia Task can easily be used to screen for unobtrusive pareidolias in all LB patients. This article is protected by copyright. All rights reserved.

View details for Web of Science ID 000859942301355

View details for PubMedID 36511519