Visual field-based reaction time as a novel indicator for early detection of mild cognitive impairment.

Early detection of mild cognitive impairment (MCI) is vital for timely intervention to delay or prevent progression to dementia. Gaze behavior analysis has been shown to differentiate individuals with MCI from cognitively healthy older adults. This study aimed to examine visual processing differences between cognitively healthy older adults and those with MCI, focusing on central and Useful Field of View (UFOV) tasks. Participants completed a central visual field task and a UFOV task. Reaction times, omission and commission errors, and visual orienting frequency were measured. Group comparisons were conducted. For variables showing significant differences, receiver operating characteristic curve analysis evaluated discriminatory accuracy and optimal cutoff values. No significant group differences emerged in the central task. In the UFOV task, patients with MCI demonstrated significantly slower reaction times than controls. The optimal UFOV reaction time cutoff was 598.1 ms, with 90.3% sensitivity, 72.1% specificity, and an area under the curve of 0.841. Older adults with MCI exhibit delayed visual processing under UFOV conditions. Reaction time in the UFOV task may serve as a sensitive, practical behavioral marker for early MCI detection.