Visual-somatosensory integration as a novel behavioral marker of amyloid pathology

INTRODUCTION: The ability to integrate information across sensory modalities is a vital aspect of everyday functioning and is linked to cognition. Increasing evidence suggests that Alzheimer's disease (AD) pathology manifests in sensory association areas before appearing in higher-order cognitive areas. We examined the role of visual-somatosensory integration (VSI) as a novel behavioral marker of AD-associated amyloid pathology. METHODS: This cross-sectional study included 243 adults (77 ± 6.5 years; 52% female) who completed the VSI test and AD biomarker assays. The magnitude of VSI was the independent variable and amyloid-beta probability scores (APS; PrecivityAD^TM) were the dependent variable. Cognitive status (normal, mild cognitive impairment, or AD) was assigned during case conferences. RESULTS: Linear regression revealed an inverse association between the magnitude of VSI and APS (β = −0.16; p ≤ 0.01). As cognitive impairment increased from normal to dementia, the magnitude of VSI decreased (p < 0.05). DISCUSSION: Findings provide support for VSI impairment as a new behavioral marker of AD-associated amyloid pathology. Highlights: Here we provide support for the magnitude of VSI as a novel behavioral marker of AD-associated amyloid pathology given its significant association with an established, accurate, and reliable biomarker of AD pathology. Adults with normal cognition maintained the highest magnitude of VSI and brain amyloid negative scores. As cognitive impairment increased, the mean magnitude of VSI significantly decreased while amyloid probability scores (APS) increased. In fact, individuals with dementia revealed the lowest magnitude of VSI and the highest APS. Our research continues to emphasize the importance of successful multisensory integration in aging, where the establishment of future novel multisensory-based interventions aimed at preventing disability and optimizing independence could prove valuable.