Steiner Genevieve Z, Gonsalvez Craig J, De Blasio Frances M, Barry Robert J
The National Institute of Complementary Medicine (NICM), Western Sydney UniversityPenrith, NSW, Australia; Centre for Psychophysics, Psychophysiology, and Psychopharmacology, Brain & Behaviour Research Institute, and School of Psychology, University of WollongongWollongong, NSW, Australia.
School of Social Sciences and Psychology, Western Sydney University Penrith, NSW, Australia.
Front Aging Neurosci. 2016 Jun 16;8:136. doi: 10.3389/fnagi.2016.00136. eCollection 2016.
In oddball tasks, the P3 component of the event-related potential systematically varies with the time between target stimuli-the target-to-target interval (TTI). Longer TTIs result in larger P3 amplitudes and shorter latencies, and this pattern of results has been linked with working memory-updating processes. Given that working memory and the P3 have both been shown to diminish with age, the current study aimed to determine whether the linear relationship between P3 and TTI is compromised in healthy aging by comparing TTI effects on P3 amplitudes and latencies, and reaction time (RT), in young and older adults. Older adults were found to have an overall reduction in P3 amplitudes, longer latencies, an anterior shift in topography, a trend toward slower RTs, and a flatter linear relationship between P3 and TTI than young adults. Results suggest that the ability to maintain templates in working memory required for stimulus categorization decreases with age, and that as a result, neural compensatory mechanisms are employed.
在异常球任务中，事件相关电位的P3成分会随着目标刺激之间的时间间隔——即目标到目标间隔（TTI）——而系统性地变化。较长的TTI会导致更大的P3波幅和更短的潜伏期，这种结果模式与工作记忆更新过程有关。鉴于工作记忆和P3都已被证明会随着年龄增长而衰退，本研究旨在通过比较TTI对年轻人和老年人的P3波幅、潜伏期以及反应时间（RT）的影响，来确定在健康衰老过程中P3与TTI之间的线性关系是否受到损害。研究发现，与年轻人相比，老年人的P3波幅总体降低，潜伏期更长，地形图上有向前移位，RT有变慢的趋势，并且P3与TTI之间的线性关系更平缓。结果表明，随着年龄增长，刺激分类所需的工作记忆中维持模板的能力会下降，因此会采用神经补偿机制。
