Martin Donel M, Burns Nicholas R, Wittert Gary
School of Psychology and Discipline of Medicine, University of Adelaide, SA, Australia.
Neuropsychology. 2009 Mar;23(2):158-67. doi: 10.1037/a0014182.
Psychometric measures of processing speed are strong predictors of cognitive functioning with aging; however, the neurobiological mechanisms underlying this association remain unclear. Recently, the authors reported a negative association between calculated free testosterone levels (cEFT) and processing speed in men aged between 50 and 70 years (Martin, Wittert, Burns, & McPherson, 2008). Ex-Gaussian decomposition of reaction time (RT) distributions allows for the robust estimation of skew in the distribution, which may reflect poorer attentional control. In a reanalysis of data from this previous study, the authors examined the associations between age, cEFT levels, and ex-Gaussian parameters derived from four RT tasks as predictors of cognitive functioning performance in 96 middle-to-older aged men. Results indicated that cEFT levels were significantly associated with increased skew in the RT distribution (i.e., the exponential portion) but not with the estimates derived from the Gaussian portion of the curve. Further, path analysis across the entire data set showed that this association was a strong predictor of processing speed performance. Taken together these results suggest that cEFT levels moderate cognitive functioning performance in males via attentional control processes.
处理速度的心理测量指标是衰老过程中认知功能的有力预测指标；然而，这种关联背后的神经生物学机制仍不清楚。最近，作者报告了50至70岁男性的计算游离睾酮水平（cEFT）与处理速度之间存在负相关（Martin、Wittert、Burns和McPherson，2008年）。反应时间（RT）分布的前高斯分解允许对分布中的偏度进行稳健估计，这可能反映出较差的注意力控制。在对该先前研究的数据进行重新分析时，作者检查了年龄、cEFT水平以及从四个RT任务得出的前高斯参数之间的关联，这些作为96名中老年男性认知功能表现的预测指标。结果表明，cEFT水平与RT分布中偏度的增加（即指数部分）显著相关，但与曲线高斯部分得出的估计值无关。此外，对整个数据集的路径分析表明，这种关联是处理速度表现的有力预测指标。综合这些结果表明，cEFT水平通过注意力控制过程调节男性的认知功能表现。
