Illusory Responses across the Lewy Body Disease Spectrum

Area of Science:

• Neurology
• Cognitive Neuroscience

Background:

• Lewy body (LB) disease spectrum often presents with subtle cognitive changes.
• Pareidolias, perceiving meaningful objects in random stimuli, are not well-studied in LB disease, especially in those without reported psychosis.

Purpose of the Study:

• To investigate the prevalence of pareidolias in patients across the Lewy body disease spectrum.
• To assess the utility of the Noise Pareidolia Task in identifying illusory responses in LB disease patients, including those without hallucinations or delusions.

Main Methods:

• 300 participants were studied: cognitively impaired LB disease, cognitively unimpaired LB disease, Alzheimer disease spectrum (AD-s), and controls.
• The Noise Pareidolia Task was used to measure illusory responses.
• Statistical analyses included pairwise comparisons and ordinal regression, with adjustments for age, sex, and education. Analyses were repeated excluding participants with reported hallucinations or delusions.

Main Results:

• Cognitively impaired LB disease patients were significantly more likely to report illusory responses compared to all other groups.
• Even after adjusting for covariates and excluding participants with psychosis, 61% of cognitively impaired LB disease patients endorsed illusory responses.
• In LB disease patients without hallucinations or delusions, 52% with mild cognitive impairment and 66.7% with dementia endorsed illusory responses.

Conclusions:

• Illusory responses are prevalent in cognitively impaired LB disease patients, irrespective of reported psychosis.
• The Noise Pareidolia Task shows promise as a screening tool for detecting early, unobtrusive signs of pareidolia in Lewy body disease patients.
• This task may aid in the early identification of LB disease, even before the manifestation of overt hallucinations or delusions.