Visual search in Alzheimer's disease and amnesticmild cognitive impairment: An eye-tracking study

INTRODUCTION: Visual search impairment is a potential cognitive marker for Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI). The aim of this study is to compare eyemovements during visual tracking inADand aMCI patients versus healthy controls (HCs). METHODS: A prospective cohort study included 32 AD and 37 aMCI patients, and 33 HCs. Each participant was asked to look at the target object in a visual stimulus containing one target and eight distractors, and eye movements were recorded with EyeLink 1000 Plus. RESULTS: AD patients had fewer fixations and shorter target fixation duration than aMCI patients and HCs. Fixation durations were also shorter in aMCI patients compared to HCs. Also, AD patients were more fixated on distractors than HCs. DISCUSSION: Our findings revealed that visual search is impaired in the early stages ofADand even aMCI, highlighting the importance of addressing visual processes in the Alzheimer's continuum.