Changes in saccade parameters during non‐visual cognitive tasks in younger and older adults

Abstract

AbstractBackgroundAlthough 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.MethodWe included 28 younger adults aged 20‐29 years and 26 older adults aged > 60 years through advertisements in community settings. All participants were free from major psychiatric, neurological, or ocular diseases. In the investigation, all participants performed the mental arithmetic task (MAT) and verbal fluency task (VFT). The primary measures were saccade parameters, including frequency, amplitude, and velocity.ResultDuring the MAT and VFT phases, the frequencies of horizontal and vertical saccades increased (p = 0.0005 for horizontal saccade in MAT; p < 0.0001 for horizontal saccade in VFT; p = 0.012 for vertical saccade in MAT; p = 0.001 for vertical saccade in VFT), but were comparable between the MAT and VFT phases. The old group showed a slower vertical saccade than the young group during the task phase (p = 0.011 in the MAT phase; p = 0.006 in the VFT phase). The amplitude of the horizontal saccade decreased in both groups during the MAT phase compared with the resting phase (p = 0.013), but did not change significantly during the VFT phase.ConclusionSaccade parameters can change during non‐visual cognitive tasks. Saccades should be examined as a potential non‐invasive biomarker of cognitive disorders in future studies.