School of Kinesiology, Louisiana State University, 1246 Pleasant Hall, Baton Rouge, LA, 70803, USA.
Department of Health and Human Performance, University of Tennessee at Martin, Elam Center, Martin, TN, 38237, USA.
Exp Brain Res. 2021 Aug;239(8):2477-2488. doi: 10.1007/s00221-021-06138-0. Epub 2021 Jun 11.
Visually guided reaching precision and accuracy depend on the level of coupling between movements of the eyes and hand. In the present study, participants performed central fixations and either saccadic or smooth pursuit eye movements during fast and accurate reaching tasks involving eye-hand coupling and decoupling to better understand type of eye movement influence over upper limb control. Some eye-hand coupling and decoupling tasks also included hand reversals, where the hand moves away from the target to direct a cursor toward the target to account for various levels of hand-cursor and eye-cursor coupling. Regardless of eye-movement type, eye-hand-cursor coupling produced an endpoint accuracy advantage over decoupling. Use of hand reversal decreased peak speed and increased response time of the hand, whether considering fixation or a given eye movement. Use of smooth pursuit slowed hand movements relative to saccades, yet improved endpoint accuracy. Compared to central fixations, using smooth pursuit also slowed hand movements, while using saccades decreased, thus improved, hand reaction times. Data suggest an advantage, when using smooth pursuit to track the hand movement for the greatest endpoint accuracy, an advantage when using saccades for the fastest movements, and an eye-hand coupling advantage when using saccades for the shortest reactions. Researchers should provide clear eye-movement instructions for participants and/or monitor the eyes when assessing similar upper limb control to account for possible differences in eye movements used. Moreover, the type of eye movement chosen for participants should correspond to the primary goal of the task.
视觉引导的伸手精度和准确性取决于眼睛和手运动之间的耦合程度。在本研究中，参与者在快速和准确的伸手任务中进行中心注视，并进行扫视或平滑追踪眼球运动，涉及眼手耦合和分离，以更好地理解眼球运动对上肢控制的影响类型。一些眼手耦合和分离任务还包括手部反转，手部离开目标，将光标指向目标，以适应各种手光标和眼光标耦合水平。无论眼球运动类型如何，眼手光标耦合在手的准确性方面优于分离。使用手部反转会降低手的峰值速度并增加手的反应时间，无论是考虑固定还是给定的眼球运动。与扫视相比，使用平滑追踪会使手部运动变慢，但会提高终点精度。与中心注视相比，使用平滑追踪也会使手部运动变慢，而使用扫视则会缩短，从而提高手部反应时间。数据表明，当使用平滑追踪来跟踪手的运动以获得最大的终点精度时具有优势，当使用扫视来获得最快的运动时具有优势，并且当使用扫视来获得最短的反应时具有眼手耦合优势。研究人员在评估类似的上肢控制时，应向参与者提供清晰的眼球运动指令和/或监测眼睛，以考虑到所使用的眼球运动可能存在差异。此外，为参与者选择的眼球运动类型应与任务的主要目标相对应。
