Institute of Physiology and Anatomy, German Sport University, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany.
Exp Brain Res. 2012 Mar;217(1):117-24. doi: 10.1007/s00221-011-2978-3. Epub 2011 Dec 17.
Earlier work suggests that the area of space from which useful visual information can be extracted (useful field of view, UFoV) shrinks in old age. We investigated whether this shrinkage, documented previously with a visual search task, extends to a bimanual tracking task. Young and elderly subjects executed two concurrent tracking tasks with their right and left arms. The separation between tracking displays varied from 3 to 35 cm. Subjects were asked to fixate straight ahead (condition FIX) or were free to move their eyes (condition FREE). Eye position was registered. In FREE, young subjects tracked equally well at all display separations. Elderly subjects produced higher tracking errors, and the difference between age groups increased with display separation. Eye movements were comparable across age groups. In FIX, elderly and young subjects tracked less well at large display separations. Seniors again produced higher tracking errors in FIX, but the difference between age groups did not increase reliably with display separation. However, older subjects produced a substantial number of illicit saccades, and when the effect of those saccades was factored out, the difference between young and older subjects' tracking did increase significantly with display separation in FIX. We conclude that the age-related shrinkage of UFoV, previously documented with a visual search task, is observable with a manual tracking task as well. Older subjects seem to partly compensate their deficit by illicit saccades. Since the deficit is similar in both conditions, it may be located downstream from the convergence of retinal and oculomotor signals.
先前的研究表明，人眼能够从中提取有用视觉信息的视野区域（有用视野，UFOV）会随着年龄的增长而缩小。我们研究了这种缩小是否会延伸到手眼协调的追踪任务中，而之前的研究是在视觉搜索任务中记录的。在这项研究中，年轻组和老年组被试分别用他们的右手和左手执行两个同时进行的追踪任务。追踪显示的分离距离从 3 厘米到 35 厘米不等。被试可以选择注视正前方（注视条件，FIX）或自由移动眼睛（自由条件，FREE）。记录眼睛位置。在 FREE 条件下，年轻组在所有显示分离距离上的追踪表现都一样好。老年组的追踪误差更高，并且年龄组之间的差异随着显示分离的增加而增加。眼动表现与年龄组无关。在 FIX 条件下，老年人和年轻人在大的显示分离时追踪表现更差。老年人在 FIX 条件下的追踪误差仍然更高，但是年龄组之间的差异并没有随着显示分离的增加而可靠地增加。然而，老年组产生了大量的非法扫视，当考虑这些扫视的影响时，在 FIX 条件下，年轻组和老年组的追踪差异随着显示分离的增加而显著增加。我们得出结论，先前在视觉搜索任务中记录的 UFOV 随年龄缩小的现象，在手眼协调的追踪任务中也可以观察到。老年组似乎通过非法扫视部分弥补了他们的缺陷。由于在两种条件下的缺陷相似，它可能位于视网膜和眼动信号融合的下游。
