Burton Catherine L, Strauss Esther, Hultsch David F, Moll Alex, Hunter Michael A
Department of Psychology, University of Victoria, Victoria, British Columbia, Canada.
J Clin Exp Neuropsychol. 2006 Jan;28(1):67-83. doi: 10.1080/13803390490918318.
Individuals with certain neurological conditions may demonstrate greater inconsistency (i.e., intraindividual variability) on cognitive tasks compared to healthy controls. Several researchers have suggested that intraindividual variability may be a behavioral marker of compromised neurobiological mechanisms associated with aging, disease, or injury. The present study sought to investigate whether intraindividual variability is associated with general nervous system compromise, or rather, with certain types of neurological disturbances by comparing healthy adults, adults with Alzheimer's disease (AD), and Parkinson's disease (PD). Participants were assessed on four separate occasions using measures of reaction time and memory. Results indicated that inconsistency was correlated with indices of severity of impairment suggesting a dose-response relationship between cognitive disturbance and intraindividual variability: the more severe the cognitive disturbance, the greater the inconsistency. However, participants with AD were more inconsistent than those with PD, with both groups being more variable than the healthy group, even when controlling for group differences in overall severity of cognitive impairment or cognitive decline. Consequently, intraindividual variability may index both the severity of cognitive impairment and the nature of the neurological disturbance.
与健康对照组相比，患有某些神经系统疾病的个体在认知任务上可能表现出更大的不一致性（即个体内变异性）。几位研究人员认为，个体内变异性可能是与衰老、疾病或损伤相关的神经生物学机制受损的行为标志。本研究旨在通过比较健康成年人、阿尔茨海默病（AD）成年人和帕金森病（PD）成年人，调查个体内变异性是与一般神经系统损害相关，还是与某些类型的神经功能障碍相关。参与者在四个不同的时间点接受反应时间和记忆测量评估。结果表明，不一致性与损伤严重程度指数相关，这表明认知障碍与个体内变异性之间存在剂量反应关系：认知障碍越严重，不一致性越大。然而，AD患者比PD患者更不一致，即使在控制了认知障碍或认知衰退总体严重程度的组间差异后，两组患者的变异性均高于健康组。因此，个体内变异性可能既反映了认知障碍的严重程度，也反映了神经功能障碍的性质。
