工作记忆和感觉运动速度在心算加工年老化过程中的作用(英文)

THE ROLE OF WORKING MEMORY AND SENSORIMOTOR SPEED IN ADUL TAGE DIFFERENCES IN MENTAL SUBTRACTION

对心算加工年老化研究有助于阐明认知老化规律 ,然而有关心算老化的少量研究结果仍存在不一致甚至矛盾之处。导致这种不一致的原因十分复杂 ,表面上看 ,不同认知老化研究所采用的统计方法不尽相同导致了结果的歧异。例如 ,在心算的年老化研究中 ,有的研究结论基于群体的数据分析 ,如层级回归分析 (hierarchicalregres sionanalyses)或方差分析 ,如Salthouse和Coon( 1994 ) ;另有一些研究先对每一个体数据作线性回归分析 ,如此得到斜率和截距 (分别表示心算的中枢加工时间和外周感觉运动时间 ) ,然后再行层级回归分析或方差分析 ,如Allen等 ( 1992 ,1997)。这两类统计分析所得的结果很不一致。从理论上看 ,只要所采用的统计方法是合理的 ,统计方法的不尽相同应不会导致矛盾。但在实际情况下 ,统计分析误差增加了结论不一致的可能性 ,从而增大了揭示心算老化复杂性规律的难度。事实上 ,心算活动的年龄差异可能来自于记忆、加工速度等不同认知资源的老化差异。为了深入探讨这一问题 ,我们进一步研究了工作记忆和感觉运动速度在心算加工年老化过程中的作用。 被试共 16 1人 ,2 0～ 79岁 ,身体健康 ,受教育年限 12年以上 ,以 10岁段划分为 6个年龄组 ,组间文化程度基本匹配。被试任务包括 :( 1)

This study, involving a total of 161 adults between 20 and 79 years of age , investigated age-related differences of cognitive processing in mental subtra ction. Aggregated and individual data analyses were conducted to evaluate the re lative importance of working memory and sensorimotor speed in adult age differen ces in mental subtraction. Overall, reaction time and errors increased with the advance of age and arithmetic task difficulty, but the magnitude of age differen ces in mental subtraction was significantly reduced by statistically controlling measures of working memory and sensorimotor speed. Moreover, there is a larger attenuation of the age-related effects on mental subtraction after control of s ensorimotor speed than after control of working memory. However, age-related di fferences in mental subtraction were not fully mediated by working memory and se nsorimotor speed.