Examination of eye movements during visual scanning of real-world images in Alzheimer's disease and amnestic mild cognitive impairment

Abstract

Available evidence shows that Alzheimer's disease (AD) patients display inefficiencies in visual scanning of their surroundings, directing their attention towards non-relevant aspects of scenes. Not much is known about eye movements during visual scanning in individuals with amnestic mild cognitive impairment (aMCI). Notably, a consensus has yet to be reached on this issue. Furthermore, prior research has indicated the existence of visual attention deficits in individuals diagnosed with AD and aMCI. The objective of this study was to examine the visual scanning patterns of individuals diagnosed with AD, aMCI, and healthy controls (HC) when viewing various scenes. Thirty patients with AD, 32 aMCI, and 32 HC were included in the study. A set of 30 real-life scene images were presented to the participants in the visual scanning task. Participants' eye events were monitored using the EyeLink 1000 Plus in this task. The results indicate a significant reduction in total fixation duration, number of scanned areas, fixation counts, and saccade counts in AD as compared to those with aMCI and HC. The research did not reveal any significant statistical differences in eye parameters between the aMCI and HC groups. This study found abnormalities in visual scanning in AD compared to aMCI and HC. Visual scanning patterns of aMCI patients were not different from HC. Previous studies have specifically shown visual attention difficulties in AD and MCI. Our findings may be related to visual attention difficulties in AD. In addition, this study is the first to examine visual scanning behaviour with real-world images in AD and aMCI.