Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany.
PLoS One. 2011 Feb 28;6(2):e17482. doi: 10.1371/journal.pone.0017482.
Several studies report an amplitude reduction of the error negativity (Ne or ERN), an event-related potential occurring after erroneous responses, in older participants. In earlier studies it was shown that the Ne can be explained by a single independent component. In the present study we aimed to investigate whether the Ne reduction usually found in older subjects is due to an altered component structure, i.e., a true alteration in response monitoring in older subjects.
METHODOLOGY/PRINCIPAL FINDINGS: Two age groups conducted two tasks with different stimulus response mappings and task difficulty. Both groups received fully balanced speed or accuracy instructions and an individually adapted deadline in both tasks. Event-related potentials, Independent Component analysis of EEG-data and between trial variability of the Ne were combined with analysis of error rates, coefficients of variation of RT-data and ex-Gaussian fittings to reaction times. The Ne was examined by means of ICA and PCA, yielding a prominent independent component on error trials, the Ne-IC. The Ne-IC was smaller in the older than the younger subjects for both speed and accuracy instructions. Also, the Ne-IC contributed to a much lesser extent to the Ne in older than in younger subjects. RT distribution parameters were not related to Ne/ERP-variability.
CONCLUSIONS/SIGNIFICANCE: The results show a genuine reduction as well as a different component structure of the Ne in older compared to young subjects. This reduction is not reflected in behaviour, apart from a general slowing of older participants. Also, the Ne decline in the elderly is not due to speed accuracy trade-off. Hence, the results indicate that older subjects can compensate the reduction in control reflected in the reduced Ne, at least in simple tasks that induce reaction slips.
多项研究报告称，在老年人中，错误相关负波（Ne 或 ERN）的振幅减小，该波是在错误反应后出现的事件相关电位。早期研究表明，Ne 可以用单个独立成分来解释。在本研究中，我们旨在研究在老年受试者中通常发现的 Ne 减少是否是由于成分结构改变，即老年受试者在反应监测中的真正改变。
方法/主要发现：两个年龄组进行了两项具有不同刺激反应映射和任务难度的任务。两组都收到了完全平衡的速度或准确性指令，并在两项任务中都收到了个人适应的截止时间。事件相关电位、脑电图数据的独立成分分析和 Ne 的试验间变异性与错误率分析、RT 数据的变异系数和反应时间的外高斯拟合相结合。通过 ICA 和 PCA 检查 Ne，在错误试验中产生一个突出的独立成分，即 Ne-IC。在速度和准确性指令下，Ne-IC 在老年人中比年轻人小。此外，在老年人中，Ne-IC 对 Ne 的贡献比年轻人小得多。RT 分布参数与 Ne/ERP 变异性无关。
结论/意义：结果表明，与年轻受试者相比，老年受试者的 Ne 确实减少了，而且成分结构也不同。除了老年参与者普遍减速外，这种减少在行为上没有反映出来。此外，老年人的 Ne 下降并不是由于速度准确性权衡。因此，结果表明，老年受试者至少可以在引发反应失误的简单任务中，通过减少的 Ne 来补偿反映在控制中的减少。
