Visual Selective Attention Toward Novel Stimuli Predicts Cognitive Decline in Alzheimer’s Disease Patients

Article type: Research Article

Authors: Chau, Sarah A.^{a; b} | Herrmann, Nathan^{a; c} | Sherman, Chelsea^{a; b} | Chung, Jonathan^{d; e} | Eizenman, Moshe^{d; e; f} | Kiss, Alex^g | Lanctôt, Krista L.^{a; b; c; *}

Affiliations: [a] Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Canada | [b] Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada | [c] Department of Psychiatry, University of Toronto, Toronto, Canada | [d] Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada | [e] Department of Electrical and Computer Engineering, University of Toronto, Toronto, Canada | [f] Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada | [g] Evaluative Clinical Sciences, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Canada

Correspondence: [*] Correspondence to: Krista Lanctôt, Neuropsychopharmacology Research Group, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Suite FG08, Toronto, ON M4N 3M5, Canada. Tel.: +1 416 480 6100 / Ext.: 2241; Fax: +1 416 480 6022; E-mail: Krista.Lanctot@sunnybrook.ca.

Abstract: Background: Alzheimer’s disease (AD) is associated with selective attention impairments, which could contribute to cognitive and functional deficits. Using visual scanning parameters, selective attention toward novel stimuli, or novelty preference, can be measured by a non-verbal, non-invasive method that may be of value in predicting disease progression. Objective: In this longitudinal study, we explored whether novelty preference can predict cognitive decline in AD patients. Methods: Mild to moderate AD patients viewed slides containing both novel and repeat images. The number of fixations, the average fixation time, and the relative fixation time on the two types of images were measured by an eye-tracking system. Novelty preference was estimated by the differences between the visual scanning parameters on novel and repeat images. Cognition and attention were assessed using the Standardized Mini-Mental Status Examination (sMMSE) and the Conners’ Continuous Performance Test (CPT), respectively. Cognition was re-assessed every 6 months for up to 2 years. Results: Multivariate linear regressions of 32 AD patients (14 females, age = 77.9±7.8, baseline sMMSE = 22.2±4.4) indicated that reduced time spent on novel images (t = 2.78, p = 0.010) was also associated with greater decline in sMMSE scores (R2 = 0.41, Adjusted R2 = 0.35, F3,28 = 6.51, p = 0.002), adjusting for attention and baseline sMMSE. Conclusion: These results suggest that novelty preference, measured by visual attention scanning technology, may reflect pathophysiological processes that could predict disease progression in the cognitively-impaired.

Keywords: Alzheimer’s disease, novelty processing, selective attention, visual scanning

DOI: 10.3233/JAD-160641

Journal: Journal of Alzheimer's Disease, vol. 55, no. 4, pp. 1339-1349, 2017