Dixon Roger A, Garrett Douglas D, Lentz Tanya L, MacDonald Stuart W S, Strauss Esther, Hultsch David F
Department of Psychology, University of Alberta, Edmonton, Alberta, Canada.
Neuropsychology. 2007 May;21(3):381-99. doi: 10.1037/0894-4105.21.3.381.
A well-known challenge for research in the cognitive neuropsychology of aging is to distinguish between the deficits and changes associated with normal aging and those indicative of early cognitive impairment. In a series of 2 studies, the authors explored whether 2 neurocognitive markers, speed (mean level) and inconsistency (intraindividual variability), distinguished between age groups (64-73 and 74-90+ years) and cognitive status groups (nonimpaired, mildly impaired, and moderately impaired). Study 1 (n = 416) showed that both level and inconsistency distinguished between the age and 2 cognitive status (not impaired, mildly impaired) groups, with a modest tendency for inconsistency to predict group membership over and above mean level. Study 2 (n = 304) replicated these results but extended them because of the qualifying effects associated with the unique moderately impaired oldest group. Specifically, not only were the groups more firmly distinguished by both indicators of speed, but evidence for the differential contribution of performance inconsistency was stronger. Neurocognitive markers of speed and inconsistency may be leading indicators of emerging cognitive impairment.
衰老认知神经心理学研究中一个众所周知的挑战是区分与正常衰老相关的缺陷和变化以及那些表明早期认知障碍的缺陷和变化。在两项研究中，作者探讨了两个神经认知指标，即速度（平均水平）和不一致性（个体内部变异性）是否能区分年龄组（64 - 73岁和74 - 90 +岁）和认知状态组（未受损、轻度受损和中度受损）。研究1（n = 416）表明，水平和不一致性都能区分年龄组以及两个认知状态（未受损、轻度受损）组，不一致性在预测组归属方面比平均水平有适度更强的趋势。研究2（n = 304）重复了这些结果，但由于与独特的最年长中度受损组相关的限定效应而对其进行了扩展。具体而言，不仅两组通过速度的两个指标得到了更明确的区分，而且表现不一致性的差异贡献的证据更强。速度和不一致性的神经认知指标可能是新出现的认知障碍的领先指标。
