Haynes Becky I, Bunce David, Kochan Nicole A, Wen Wei, Brodaty Henry, Sachdev Perminder S
School of Psychology, Faculty of Medicine and Health, University of Leeds, Leeds, UK.
School of Psychology, Faculty of Medicine and Health, University of Leeds, Leeds, UK; Centre for Health Brain Ageing (CHeBA), School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia.
Neuropsychologia. 2017 Feb;96:249-255. doi: 10.1016/j.neuropsychologia.2017.01.021. Epub 2017 Jan 21.
In old age, a relationship has been reported between intraindividual variability (IIV) in reaction time and white matter integrity as evidenced by white matter hyperintensities (WMH). However, it is unclear how far such associations are due to incipient neurodegenerative pathology in the samples investigated. The present study examined the relationship between IIV and WMH in older individuals (N=526) drawn from the Sydney Memory and Ageing Study. Using a complex reaction time (RT) task, greater IIV and mean-RT were related to a higher WMH burden in the frontal lobe. Critically, significant associations remained having taken future dementia into account suggesting that they were not explained by incipient dementia. Additionally, independent measures of executive function accounted for the association between RT metrics and WHM. The results are consistent with the view that frontally-supported cognitive processes are involved in IIV-WMH relations, and that RT measures are sensitive to compromise in white matter structures in non-demented older individuals.
在老年人群中，反应时间的个体内变异性（IIV）与白质完整性之间存在关联，白质高信号（WMH）可证明这一点。然而，在研究样本中，这种关联在多大程度上归因于早期神经退行性病变尚不清楚。本研究调查了来自悉尼记忆与衰老研究的老年个体（N = 526）中IIV与WMH之间的关系。使用复杂反应时间（RT）任务，更大的IIV和平均反应时间与额叶更高的WMH负担相关。至关重要的是，在考虑到未来患痴呆症的情况后，显著关联仍然存在，这表明它们无法用早期痴呆症来解释。此外，执行功能的独立测量解释了RT指标与WMH之间的关联。结果与以下观点一致：额叶支持的认知过程参与了IIV-WMH关系，并且RT测量对非痴呆老年个体白质结构的损害敏感。
