Padgaonkar Namita A, Zanto Theodore P, Bollinger Jacob, Gazzaley Adam
Department of Neurology, University of California San Francisco, San Francisco, CA, USA.
Department of Neurology, University of California San Francisco, San Francisco, CA, USA.
Neurobiol Aging. 2017 Jan;49:31-39. doi: 10.1016/j.neurobiolaging.2016.09.002. Epub 2016 Sep 13.
Older adults, compared to younger adults, do not benefit from predictive information regarding either what type of stimuli they will see or when to expect them, yet it is unclear whether older adults benefit when given both types of predictive information. Here, electroencephalogram recordings of older (aged 62-87 years) and younger (aged 20-32 years) adults were recorded during a working memory task. Each trial contained 2 faces and 2 scenes presented sequentially, followed by a 5-second delay and a probe stimulus. Participants were told what stimuli to remember/ignore and when they would appear. Predictive cues enabled older adults to remember stimuli as accurately as younger adults, although response times were significantly slower, even when corrected for general age-related slowing. Previously observed reductions in P1/N1 amplitude and latency suppression to irrelevant stimuli were not seen. Rather, older adults exhibited lowered P3 amplitudes to relevant stimuli; those with the greatest declines yielded the lowest accuracy and slowest response times. This shows that predictive information can help maintain accuracy, although not response times, which correspond to age-related declines in neural enhancement to relevant stimuli.
与年轻人相比，老年人无法从关于他们将看到何种类型刺激或何时会出现刺激的预测信息中获益，但尚不清楚当同时给予这两种类型的预测信息时老年人是否会从中受益。在此，在一项工作记忆任务中记录了老年人（62 - 87岁）和年轻人（20 - 32岁）的脑电图。每个试验包含依次呈现的2张面孔和2个场景，随后是5秒的延迟和一个探测刺激。参与者被告知要记住/忽略哪些刺激以及它们何时会出现。预测线索使老年人能够像年轻人一样准确地记住刺激，尽管反应时间显著更慢，即使校正了与年龄相关的普遍反应迟缓也是如此。之前观察到的对无关刺激的P1/N1振幅和潜伏期抑制的降低并未出现。相反，老年人对相关刺激的P3振幅降低；下降幅度最大的那些人准确性最低且反应时间最慢。这表明预测信息有助于保持准确性，尽管不能缩短反应时间，反应时间与对相关刺激的神经增强方面与年龄相关的下降相对应。
