Neuropsychiatric and Cognitive Correlates of Pareidolias in Dementia with Lewy Bodies

Pareidolias represent visual illusions of meaningful objects in ambiguous stimuli. Prior research has demonstrated phenomenological similarities between pareidolias and visual hallucinations (VH) and the potential clinical utility of pareidolias in discriminating dementia with Lewy bodies (DLB) from Alzheimer's dementia (ad). Though pareidolias have been linked with VH severity in DLB, the relationships between pareidolias and other neuropsychiatric symptoms have not been explored in large DLB samples.Individuals meeting 2017 McKeith criteria for probable DLB (n = 114) were enrolled in a multi-site systematic longitudinal study of the US DLB Consortium. Study assessments included an informant-rated psychiatric inventory (NPI), Montreal Cognitive Assessment (MoCA), and Noise Pareidolia Task (NPT). Ninety-five participants completed all clinical assessments. To examine baseline relationships between pareidolias responses (NPT) and the presence of 12 neuropsychiatric symptom dimensions (NPI), we used Poisson regression models with robust standard error estimates adjusted for age, education, disease duration, cognition (MoCA), and cholinesterase inhibitor use.Contrary to expectation, the presence of VH was not associated with pareidolias in DLB (Incidence Rate Ratio = 1.37, p = 0.275). The presence of both delusions (IRR = 2.11, p = 0.01) and depression (IRR = 1.79, p = 0.015) was associated with greater pareidolias. Additionally, overall cognitive dysfunction was associated with pareidolias (IRR = 0.90, p < 0.001).Our findings indicate that pareidolias are associated with poorer cognition and neuropsychiatric dimensions beyond VH, including depression and delusions. As pareidolias have been put forth as a surrogate marker of VH in DLB, future studies examining pareidolias in conjunction with comprehensive psychiatric/cognitive assessment and neuroimaging will further elucidate the clinical utility of pareidolia testing.