Exploring age-related changes in saccades during cognitive tasks in healthy adults

Although eye movements such as saccades are related to internal cognitive processes and are independent of visual processing, few studies have investigated whether non-visual cognitive tasks simultaneously affect horizontal and vertical saccades in younger and older adults. We recruited 28 younger adults aged 20-29 years and 26 older adults aged >60 years through advertisements in community settings. All participants were free of major psychiatric, neurological, or ocular diseases. All participants performed the mental arithmetic task (MAT) and verbal fluency task (VFT). The primary measures were saccade parameters, including frequency, mean amplitude, and mean velocity. During MAT and VFT, the frequencies of horizontal and vertical saccades increased ( = 0.0005 for horizontal saccade in MAT;