Research Centre for Mind, Brain and Behaviour, University of Granada, Granada, Spain.
School of Psychology, University of Birmingham, Birmingham, United Kingdom.
Sci Rep. 2019 Jul 10;9(1):9977. doi: 10.1038/s41598-019-46214-8.
Seemingly effortless tasks, such as recognizing faces and retrieving names, become harder as we age. Such difficulties may be due to the competition generated in memory by irrelevant information that comes to mind when trying to recall a specific face or name. It is unknown, however, whether age-related struggles in retrieving these representations stem from an inability to detect competition in the first place, or from being unable to suppress competing information once interference is detected. To investigate this, we used the retrieval practice paradigm, shown to elicit memory interference, while recording electrophysiological activity in young and older adults. In two experiments, young participants showed Retrieval-Induced Forgetting (RIF), reflecting the suppression of competing information, whereas older adults did not. Neurally, mid-frontal theta power (~4-8 Hz) during the first retrieval cycle, a proxy for interference detection, increased in young compared to older adults, indicating older adults were less capable of detecting interference. Moreover, while theta power was reduced across practice cycles in younger adults, a measure of interference resolution, older adults did not show such a reduction. Thus, in contrast with younger adults, the lack of an early interference detection signal rendered older adults unable to recruit memory selection mechanisms, eliminating RIF.
看似毫不费力的任务，如识别面孔和检索姓名，随着年龄的增长会变得更加困难。这种困难可能是由于在试图回忆特定面孔或姓名时，脑海中浮现出的无关信息所产生的记忆竞争。然而，尚不清楚这些代表人物检索中与年龄相关的困难是源于一开始无法检测到竞争，还是源于一旦检测到干扰就无法抑制竞争信息。为了研究这一点，我们使用了检索练习范式，该范式会引发记忆干扰，同时记录年轻和老年成年人的脑电图活动。在两项实验中，年轻参与者表现出检索诱导遗忘（Retrieval-Induced Forgetting，RIF），反映出对竞争信息的抑制，而老年参与者则没有。神经上，与老年参与者相比，年轻人在第一个检索周期中额前θ功率（~4-8 Hz）增加，这是干扰检测的一个指标，表明老年参与者检测干扰的能力较差。此外，虽然年轻成年人在练习周期中θ功率会降低，这是干扰分辨率的一个衡量标准，但老年成年人并没有表现出这种降低。因此，与年轻成年人相比，缺乏早期干扰检测信号使得老年成年人无法招募记忆选择机制，从而消除了 RIF。
