Iowa State University, Ames, IA, USA.
Cortex. 2010 Apr;46(4):550-63. doi: 10.1016/j.cortex.2009.08.001. Epub 2009 Aug 13.
Studies examining the effects of aging in the oddball task have consistently revealed an age-related change in the topography of the P3 component. Specifically, in younger adults the amplitude of this component is greatest over the parietal region of the scalp while in older adults the P3 is more evenly distributed over the parietal and frontal regions of the scalp. In the current study, Partial Least Squares (PLS) analysis was used to examine the effects of age on the full time course and topography of the event-related brain potentials (ERPs) elicited during the oddball task; and to consider the influence of individual differences in executive function on age-related differences in the oddball task. Aging and individual differences appeared to have relatively little effect on the P3b that distinguished oddball stimulus from standards. The age-related "anterior shift" in the P3 appeared to result from the stronger expression of the novelty P3 in older adults relative to younger adults, as this effect was seen for both oddball and novel stimuli relative to standard stimuli. Additionally, the effect of age interacted with variation in executive function, with the novelty P3 being elicited for novel and oddball stimuli in the low executive older adults and only for novel stimuli in the high executive older adults. These findings lead to the suggestion that the age-related anterior shift in the P3 may result from the failure of older adults with lower executive functions to habituate to the oddball stimulus.
研究衰老对异常刺激任务的影响发现，P3 成分的地形图随年龄而变化。具体来说，在年轻成年人中，该成分的振幅在头皮的顶叶区域最大，而在老年成年人中，P3 更均匀地分布在头皮的顶叶和额叶区域。在当前的研究中，偏最小二乘法（PLS）分析用于检查年龄对异常刺激任务中诱发的事件相关脑电位（ERPs）的整个时间过程和地形图的影响；并考虑执行功能个体差异对异常刺激任务中年龄相关差异的影响。衰老和个体差异似乎对区分异常刺激和标准刺激的 P3b 影响相对较小。P3 中的与年龄相关的“前移位”似乎是由于老年人相对于年轻人对新颖性 P3 的表达更强，因为这种效应在异常刺激和新颖刺激相对于标准刺激时都可见。此外，年龄的影响与执行功能的变化相互作用，在执行功能较低的老年成年人中，新颖性和异常刺激会引起新颖性 P3，而在执行功能较高的老年成年人中，只有新颖刺激会引起新颖性 P3。这些发现表明，P3 中的与年龄相关的前移位可能是由于执行功能较低的老年人无法习惯异常刺激所致。
