Ren Jie, Huang Shaochen, Zhang Jiancheng, Zhu Qin, Wilson Andrew D, Snapp-Childs Winona, Bingham Geoffrey P
Key Laboratory of Exercise and Health Sciences, Shanghai University of Sport, Shanghai, China.
Key Laboratory of Exercise and Health Sciences, Shanghai University of Sport, Shanghai, China; Kinesiology and Health, University of Wyoming, Laramie, WY, United States of America.
PLoS One. 2015 Apr 13;10(4):e0121708. doi: 10.1371/journal.pone.0121708. eCollection 2015.
Previously, we measured perceptuo-motor learning rates across the lifespan and found a sudden drop in learning rates between ages 50 and 60, called the "50s cliff." The task was a unimanual visual rhythmic coordination task in which participants used a joystick to oscillate one dot in a display in coordination with another dot oscillated by a computer. Participants learned to produce a coordination with a 90° relative phase relation between the dots. Learning rates for participants over 60 were half those of younger participants. Given existing evidence for visual motion perception deficits in people over 60 and the role of visual motion perception in the coordination task, it remained unclear whether the 50s cliff reflected onset of this deficit or a genuine decline in perceptuo-motor learning. The current work addressed this question. Two groups of 12 participants in each of four age ranges (20s, 50s, 60s, 70s) learned to perform a bimanual coordination of 90° relative phase. One group trained with only haptic information and the other group with both haptic and visual information about relative phase. Both groups were tested in both information conditions at baseline and post-test. If the 50s cliff was caused by an age dependent deficit in visual motion perception, then older participants in the visual group should have exhibited less learning than those in the haptic group, which should not exhibit the 50s cliff, and older participants in both groups should have performed less well when tested with visual information. Neither of these expectations was confirmed by the results, so we concluded that the 50s cliff reflects a genuine decline in perceptuo-motor learning with aging, not the onset of a deficit in visual motion perception.
此前，我们测量了整个生命周期中的感知运动学习率，发现在50岁至60岁之间学习率突然下降，即所谓的“50岁悬崖”。任务是一项单手视觉节奏协调任务，参与者使用操纵杆使显示屏上的一个点与计算机控制摆动的另一个点同步摆动。参与者要学会使两个点之间产生90°相对相位关系的协调动作。60岁以上参与者的学习率只有年轻参与者的一半。鉴于现有证据表明60岁以上人群存在视觉运动感知缺陷，以及视觉运动感知在协调任务中的作用，尚不清楚“50岁悬崖”是反映了这种缺陷的开始，还是感知运动学习的真正下降。当前的研究解决了这个问题。四个年龄组（20多岁、50多岁、60多岁、70多岁）各有两组，每组12名参与者，学习进行90°相对相位的双手协调动作。一组仅通过触觉信息进行训练，另一组同时通过触觉和视觉信息了解相对相位。两组在基线和测试后都在两种信息条件下进行测试。如果“50岁悬崖”是由视觉运动感知方面与年龄相关的缺陷引起的，那么视觉组中的老年参与者应该比触觉组中的老年参与者表现出更少的学习，触觉组不应出现“50岁悬崖”，并且两组中的老年参与者在使用视觉信息进行测试时表现应该更差。结果并未证实这些预期，因此我们得出结论，“50岁悬崖”反映了随着年龄增长感知运动学习的真正下降，而不是视觉运动感知缺陷的开始。
