Dissociative effects of age on neural differentiation at the category and item level.
Dissociative effects of age on neural differentiation at the category and item level.
复制标题
年龄对类别和项目级别神经分化的解离效应。
DOI：
10.1101/2023.05.24.542148
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Rugg,MichaelD
中科院分区：
文献类型：
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作者：
Srokova,Sabina;Aktas,AyseNZ;Koen,JoshuaD;Rugg,MichaelD
年龄的增长与年龄相关的神经去分化有关，神经表征的选择性降低，这被认为是导致老年认知能力下降的原因。最近的研究结果表明，当操作在不同的感知类别的选择性，年龄相关的神经去分化和明显的年龄不变的神经选择性与认知性能的关联，在很大程度上限制在场景处理过程中通常招募的皮层区域。目前尚不清楚这种类别水平的解离是否扩展到在单个刺激项水平上定义的神经选择性指标。在这里，我们研究了神经的选择性在类别和项目水平上使用多体素模式相似性分析（PSA）的功能磁共振成像数据。健康的年轻人和老年人男性和女性观看物体和场景的图像。有些项目是单独呈现的，而另一些项目则是重复出现的，或者后面跟着一个“类似的诱饵”。与最近的研究结果一致，类别水平的PSA显示，在场景选择性，但不是对象选择性，皮层区域的老年人比年轻人的分化明显较低。相比之下，在项目水平，强大的年龄相关的神经分化下降是显而易见的两个刺激类别。此外，我们确定了一个年龄不变的关联类别级别的场景选择性在海马旁的地方区和随后的记忆表现，但没有这样的关联是明显的项目级指标。最后，类别级和项目级神经指标不相关。因此，本研究结果表明，年龄相关的类别和项目水平的去分化依赖于不同的神经机制。
Increasing age is associated with age-related neural dedifferentiation, a reduction in the selectivity of neural representations, which has been proposed to contribute to cognitive decline in older age. Recent findings indicate that when operationalized in terms of selectivity for different perceptual categories, age-related neural dedifferentiation and the apparent age-invariant association of neural selectivity with cognitive performance are largely restricted to the cortical regions typically recruited during scene processing. It is currently unknown whether this category-level dissociation extends to metrics of neural selectivity defined at the level of individual stimulus items. Here, we examined neural selectivity at the category and item levels using multivoxel pattern similarity analysis (PSA) of fMRI data. Healthy young and older male and female adults viewed images of objects and scenes. Some items were presented singly, while others were either repeated or followed by a “similar lure.” In agreement with recent findings, category-level PSA revealed robustly lower differentiation in older than in younger adults in scene-selective, but not object-selective, cortical regions. By contrast, at the item level, robust age-related declines in neural differentiation were evident for both stimulus categories. Additionally, we identified an age-invariant association between category-level scene selectivity in the parahippocampal place area and subsequent memory performance, but no such association was evident for item-level metrics. Lastly, category- and item-level neural metrics were uncorrelated. Thus, the present findings suggest that age-related category- and item-level dedifferentiation depend on distinct neural mechanisms.