Soldan Anja, Gazes Yunglin, Hilton H John, Stern Yaakov
Columbia University Medical Center, New York, NY, USA.
J Cogn Neurosci. 2008 Oct;20(10):1762-76. doi: 10.1162/jocn.2008.20130.
This study examined how aging affects the spatial patterns of repetition effects associated with perceptual priming of unfamiliar visual objects. Healthy young (n = 14) and elderly adults (n = 13) viewed four repetitions of structurally possible and impossible figures while being scanned with blood oxygenation level-dependent functional magnetic resonance imaging. Although explicit recognition memory for the figures was reduced in the elder subjects, repetition priming did not differ across the two age groups. Using multivariate linear modeling, we found that the spatial networks of regions that demonstrated repetition-related increases and decreases in activity were identical in both age groups, although there was a trend for smaller magnitude repetition effects in these networks in the elder adults for objects that had been repeated thrice. Furthermore, repetition-related reductions in activity in the left inferior frontal cortex for possible objects correlated with repetition-related facilitation in reaction time across both young and elder subjects. Repetition-related increases of an initially negative response were observed for both object types in both age groups in parts of the default network, suggesting that less attention was required for processing repeated stimuli. These findings extend prior studies using verbal and semantic picture priming tasks and support the view that perceptual repetition priming remains intact in later adulthood because the same spatial networks of regions continue to show repetition-related neural plasticity across the adult life span.
本研究探讨了衰老如何影响与不熟悉视觉对象的知觉启动相关的重复效应的空间模式。健康的年轻成年人（n = 14）和老年人（n = 13）在接受血氧水平依赖性功能磁共振成像扫描时，观看了结构上可能和不可能的图形的四次重复呈现。尽管老年受试者对图形的明确识别记忆有所下降，但两个年龄组的重复启动并无差异。使用多元线性模型，我们发现，在两个年龄组中，显示出与重复相关的活动增加和减少的区域的空间网络是相同的，尽管在老年成年人中，对于重复三次的对象，这些网络中的重复效应幅度有变小的趋势。此外，在年轻和老年受试者中，对于可能的对象，左侧额下回与重复相关的活动减少与反应时间上的重复相关促进作用相关。在默认网络的部分区域，两个年龄组的两种对象类型均观察到与重复相关的最初负性反应的增加，这表明处理重复刺激所需的注意力较少。这些发现扩展了先前使用言语和语义图片启动任务的研究，并支持以下观点：知觉重复启动在成年后期仍然完好无损，因为相同的区域空间网络在整个成年期都继续表现出与重复相关的神经可塑性。
