Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX 75235.
School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX 75080.
Cereb Cortex. 2021 Jan 1;31(1):106-122. doi: 10.1093/cercor/bhaa210.
Age-related reductions in neural selectivity have been linked to cognitive decline. We examined whether age differences in the strength of retrieval-related cortical reinstatement could be explained by analogous differences in neural selectivity at encoding, and whether reinstatement was associated with memory performance in an age-dependent or an age-independent manner. Young and older adults underwent fMRI as they encoded words paired with images of faces or scenes. During a subsequent scanned memory test participants judged whether test words were studied or unstudied and, for words judged studied, also made a source memory judgment about the associated image category. Using multi-voxel pattern similarity analyses, we identified robust evidence for reduced scene reinstatement in older relative to younger adults. This decline was however largely explained by age differences in neural differentiation at encoding; moreover, a similar relationship between neural selectivity at encoding and retrieval was evident in young participants. The results suggest that, regardless of age, the selectivity with which events are neurally processed at the time of encoding can determine the strength of retrieval-related cortical reinstatement.
与认知能力下降相关的与年龄相关的神经选择性降低。我们研究了在编码时检索相关的皮质再激活的强度上的年龄差异是否可以用类似的神经选择性差异来解释，以及再激活是否以依赖于年龄或独立于年龄的方式与记忆表现相关。年轻和年长的成年人在编码时接受 fMRI 扫描，编码时将单词与面部或场景的图像配对。在随后的扫描记忆测试中，参与者判断测试单词是否学习过或未学习过，并且对于判断为学习过的单词，还对相关的图像类别做出了源记忆判断。使用多体素模式相似性分析，我们确定了相对于年轻成年人，年长成年人的场景再激活减少的有力证据。然而，这种下降在很大程度上可以用编码时的神经分化的年龄差异来解释；此外，在年轻参与者中，编码时的神经选择性与检索之间存在类似的关系。研究结果表明，无论年龄大小，在编码时事件的神经处理的选择性都可以决定与检索相关的皮质再激活的强度。
