摘要：SummarySaccadic eye movements may not stop steadily but fluctuate briefly, known as saccadic dynamic overshoot (SDO). The reported relationships between SDO and saccadic parameters of main saccade and the effect of aging on SDO are controversial. In addition, it is not clear whether aging-related disease, such as mild cognitive impairment (MCI) and Parkinson disease (PD), causes the specific change of SDO. To address these questions, we analyzed the spatiotemporal features of SDO in young healthy subjects, elderly healthy subjects, and subjects with PD and MCI in three oculomotor tasks. We found two types of SDOs—simple and complex SDO. We confirmed that the frequency and amplitude of SDO were positively correlated with the peak velocity and deceleration of main saccades and increased in elderly subjects; however, they were not significantly different among the three elderly groups. Our results support the previous argument that the oculomotor structure in brainstem and cerebellum directly develop SDO.Graphical abstractDisplay OmittedHighlights•We classify two types of saccadic dynamic overshoot (SDO): SDOsimpleand SDOcomplex•Saccades with SDO have higher peak velocity and deceleration than saccades without SDO•Elderly subjects show a higher frequency and amplitude of SDO than young subjects•Saccades with SDOcomplexoccur more frequently in reflexive than voluntary saccadesBehavioral neuroscience; Cognitive neuroscience
