Godefroy Olivier, Roussel Martine, Despretz Pascal, Quaglino Véronique, Boucart Muriel
Department of Neurology and Laboratoire de Neurosciences Fonctionnelles et Pathologies, Amiens University Hospital, Amiens Cedex, France.
Exp Aging Res. 2010 Apr;36(2):169-89. doi: 10.1080/03610731003613615.
Age-related slowing is well documented but its origin remains unclear. A first validation study (Study 1) performed in 46 participants examined the effect of attention allocation (manipulated through a dual task) on various portions of individual simple reaction time (SRT) distribution (minimum, centile 5, centile 50, and centile 95 RTs). It showed that attention 'deprivation' due to a secondary task is not uniform throughout the distribution but impaired mainly the ability to produce a large number of fast responses. Study 2 investigated in 88 healthy participants age-related slowing of perceptual, motor, decision, and attentional processes using SRT and choice reaction time (CRT), finger tapping, and visual inspection time tests. It showed that the majority of SRT slowing after the age of 40 is due to lengthening of centile 5 RT, suggesting perceptuomotor slowing, an interpretation supported by longer visual inspection time and lower tapping frequency. After 60 years, SRT lengthening was due to a further lengthening of the centile 5-centile 50 SRT index, suggesting the participation of attentional decline. These findings support the hypothesis that age-related slowing in simple repetitive tasks is mainly related to slowing at the stage of perceptuomotor processes, and after 60 years, to additional decline of attention.
与年龄相关的反应速度减慢现象有充分的文献记载，但其根源仍不明确。在46名参与者中进行的第一项验证性研究（研究1），考察了注意力分配（通过双重任务进行操纵）对个体简单反应时间（SRT）分布的不同部分（最短反应时间、第5百分位数、第50百分位数和第95百分位数反应时间）的影响。结果表明，由于次要任务导致的注意力“剥夺”在整个分布中并不均匀，主要损害的是产生大量快速反应的能力。研究2在88名健康参与者中，使用SRT、选择反应时间（CRT）、手指敲击和视觉检查时间测试，研究了与年龄相关的感知、运动、决策和注意力过程的减慢情况。结果表明，40岁以后SRT减慢的主要原因是第5百分位数反应时间延长，这表明感知运动减慢，视觉检查时间延长和敲击频率降低支持了这一解释。60岁以后，SRT延长是由于第5百分位数至第50百分位数SRT指数进一步延长，这表明注意力下降也起到了作用。这些发现支持了以下假设：在简单重复任务中，与年龄相关的反应速度减慢主要与感知运动过程阶段的减慢有关，60岁以后，则与注意力的额外下降有关。
