Maki B E, Zecevic A, Bateni H, Kirshenbaum N, McIlroy W E
Centre for Studies in Aging, Sunnybrook and Women's College Health Sciences Centre, 2075 Bayview Avenue, Toronto, Canada M4N 3M5.
Neuroreport. 2001 Nov 16;12(16):3583-7. doi: 10.1097/00001756-200111160-00042.
A new dual-task paradigm was used to investigate age-related differences in attentional dynamics during rapid balancing reactions evoked by small, unpredictable antero-posterior platform movements. The perturbations were delivered while subjects performed a continuous visuo-motor pursuit-tracking task. Onset of significant deviation in tracking was inferred to indicate switching of attentional resources between tracking and balancing tasks. Although tracking deviation was equally likely to occur subsequent to postural perturbation in healthy young and older adults, deviation onset was delayed, on average, by 67% (123 ms) in the older subjects. Delay in onset of tracking deviation correlated with subsequent delay in generating the peak stabilizing postural response at the ankle. These results suggest that impaired attentional dynamics may exacerbate postural instability in older adults.
采用一种新的双任务范式，研究在由不可预测的小幅度前后平台运动引发的快速平衡反应过程中，注意力动态方面与年龄相关的差异。在受试者执行连续的视觉运动追踪任务时施加干扰。追踪中显著偏差的开始被推断为表明注意力资源在追踪和平衡任务之间的切换。尽管在健康的年轻人和老年人中，姿势干扰后追踪偏差同样有可能发生，但在老年受试者中，偏差开始平均延迟了67%（123毫秒）。追踪偏差开始的延迟与随后踝关节产生峰值稳定姿势反应的延迟相关。这些结果表明，注意力动态受损可能会加剧老年人的姿势不稳定。
