Max Planck Institute for Human Development, Berlin, Germany.
J Cogn Neurosci. 2013 Feb;25(2):188-202. doi: 10.1162/jocn_a_00303. Epub 2012 Sep 27.
Declines in selective attention are one of the sources contributing to age-related impairments in a broad range of cognitive functions. Most previous research on mechanisms underlying older adults' selection deficits has studied the deployment of visual attention to static objects and features. Here we investigate neural correlates of age-related differences in spatial attention to multiple objects as they move. We used a multiple object tracking task, in which younger and older adults were asked to keep track of moving target objects that moved randomly in the visual field among irrelevant distractor objects. By recording the brain's electrophysiological responses during the tracking period, we were able to delineate neural processing for targets and distractors at early stages of visual processing (~100-300 msec). Older adults showed less selective attentional modulation in the early phase of the visual P1 component (100-125 msec) than younger adults, indicating that early selection is compromised in old age. However, with a 25-msec delay relative to younger adults, older adults showed distinct processing of targets (125-150 msec), that is, a delayed yet intact attentional modulation. The magnitude of this delayed attentional modulation was related to tracking performance in older adults. The amplitude of the N1 component (175-210 msec) was smaller in older adults than in younger adults, and the target amplification effect of this component was also smaller in older relative to younger adults. Overall, these results indicate that normal aging affects the efficiency and timing of early visual processing during multiple object tracking.
选择性注意力下降是导致广泛认知功能随年龄增长而受损的原因之一。大多数关于老年人选择缺陷背后机制的先前研究都研究了静态物体和特征的视觉注意力的部署。在这里，我们研究了随着物体的移动，对多个物体的空间注意力的年龄相关差异的神经相关性。我们使用了一个多目标跟踪任务，要求年轻和年长的成年人在视觉场中随机移动的目标物体与无关的分心物体之间跟踪移动的目标物体。通过在跟踪期间记录大脑的电生理反应，我们能够描绘出在视觉处理的早期阶段（~100-300 msec）对目标和分心物的神经处理。与年轻成年人相比，年长成年人在视觉 P1 成分的早期阶段（100-125 msec）表现出较少的选择性注意力调节，这表明在老年时早期选择受到损害。然而，与年轻成年人相比，年长成年人在 25 msec 的延迟后显示出目标的明显处理（125-150 msec），即延迟但完整的注意力调节。这种延迟的注意力调节的幅度与年长成年人的跟踪表现有关。与年轻成年人相比，年长成年人的 N1 成分（175-210 msec）的振幅较小，并且该成分的目标放大效应在年长成年人中也较小。总体而言，这些结果表明，正常衰老会影响多目标跟踪期间早期视觉处理的效率和时间。
