Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QB, UK; School of Psychology, University of Glasgow, Glasgow G12 8QB, UK.
Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QB, UK; School of Psychology, University of Glasgow, Glasgow G12 8QB, UK.
Neuroimage. 2017 Jun;153:139-151. doi: 10.1016/j.neuroimage.2017.03.050. Epub 2017 Mar 23.
A group-level visuospatial attention bias towards the left side of space (pseudoneglect) is consistently observed in young adults, which is likely to be a consequence of right parieto-occipital dominance for spatial attention. Conversely, healthy older adults demonstrate a rightward shift of this behavioural bias, hinting that an age-related reduction of lateralised neural activity may occur within visuospatial attention networks. We compared young (aged 18-25) and older (aged 60-80) adults on a computerised line bisection (landmark) task whilst recording event-related potentials (ERPs). Full-scalp cluster mass permutation tests identified a larger right parieto-occipital response for long lines compared to short in young adults (confirming Benwell et al., 2014a) which was not present in the older group. To specifically investigate age-related differences in hemispheric lateralisation, cluster mass permutation tests were then performed on a lateralised EEG dataset (RH-LH electrodes). A period of right lateralisation was identified in response to long lines in young adults, which was not present for short lines. No lateralised clusters were present for either long or short lines in older adults. Additionally, a reduced P300 component amplitude was observed for older adults relative to young. We therefore report here, for the first time, an age-related and stimulus-driven reduction of right hemispheric control of spatial attention in older adults. Future studies will need to determine whether this is representative of the normal aging process or an early indicator of neurodegeneration.
年轻成年人中普遍存在一种对左侧空间的群体水平视空间注意偏向（假性忽视），这很可能是右顶枕区对空间注意的优势所致。相反，健康的老年人则表现出这种行为偏向的右移，暗示在视空间注意网络中，与年龄相关的偏侧化神经活动减少可能会发生。我们在一项计算机化的直线二分（地标）任务中比较了年轻（18-25 岁）和老年（60-80 岁）成年人，同时记录事件相关电位（ERP）。全头皮集群质量置换检验确定了年轻成年人中长线相对于短线的右顶枕区反应更大（证实了 Benwell 等人，2014a），而老年组则没有。为了专门研究与年龄相关的半球侧化差异，集群质量置换检验随后在一个侧化 EEG 数据集（RH-LH 电极）上进行。在年轻成年人中，对长线条的反应中确定了一个右偏侧化的时期，而对短线条则不存在。老年成年人对长或短线条都没有出现偏侧化集群。此外，与年轻人相比，老年人的 P300 成分幅度减小。因此，我们在这里首次报告了与年龄相关的、由刺激驱动的老年人空间注意右侧控制的减少。未来的研究需要确定这是否代表正常的衰老过程还是神经退行性变的早期指标。
