The Relationship between Age, Neural Differentiation, and Memory Performance
The Relationship between Age, Neural Differentiation, and Memory Performance
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DOI：
10.1523/jneurosci.1498-18.2018
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发表时间：
2019-01-02
影响因子：
5.3
通讯作者：
Rugg, Michael D.
中科院分区：
文献类型：
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作者：
Koen, Joshua D.;Hauck, Nedra;Rugg, Michael D.
健康的老龄化与类别选择性皮层区域的神经选择性（去分化）降低有关。这一发现促使人们提出去分化导致与年龄相关的认知能力下降的建议。与这种可能性相一致的是，据报道，去分化与老年人的液体智力呈负相关。在这里，我们研究了去分化是否与另一个认知领域的表现有关-情节记忆-这也是非常容易老化。考虑到去分化在年龄相关的认知能力下降中的作用，我们预测老年人的去分化和情景记忆表现之间的联系比年轻人更强。年轻（18 - 30岁）和老年（64 - 75岁）的男性和女性在观看物体和场景的图像时接受了fMRI扫描，然后进行了随后的识别记忆测试。我们计算了两个感兴趣区域（ROI）的分化指数：海马旁位置区（PPA）和枕叶外侧复合体（OCI）。该指数量化了BOLD响应对ROI的首选与非首选类别的选择性（PPA的场景，对象）。老年人PPA的分化指数低于年轻人，但PPA的分化指数不低于老年人。此外，PPA分化指数预测识别记忆性能的研究项目。这种关系是独立的，不受年龄的调节。PPA分化指数还预测了一个潜在的“流畅性”因素来自神经心理测试电池的性能，这种关系也是年龄不变的。这些发现表明，两个独立的因素，一个与年龄相关，另一个与认知能力，影响神经分化。
Healthy aging is associated with decreased neural selectivity (dedifferentiation) in category-selective cortical regions. This finding has prompted the suggestion that dedifferentiation contributes to age-related cognitive decline. Consistent with this possibility, dedifferentiation has been reported to negatively correlate with fluid intelligence in older adults. Here, we examined whether dedifferentiation is associated with performance in another cognitive domain- episodic memory-that is also highly vulnerable to aging. Given the proposed role of dedifferentiation in age-related cognitive decline, we predicted there would be a stronger link between dedifferentiation and episodic memory performance in older than in younger adults. Young (18 -30 years) and older (64 -75 years) male and female humans underwent fMRI scanning while viewing images of objects and scenes before a subsequent recognition memory test. We computed a differentiation index in two regions of interest (ROIs): parahippocampal place area (PPA) and lateral occipital complex (LOC). This index quantified the selectivity of the BOLD response to preferred versus nonpreferred category of an ROI (scenes for PPA, objects for LOC). The differentiation index in the PPA, but not the LOC, was lower in older than in younger adults. Additionally, the PPA differentiation index predicted recognition memory performance for the studied items. This relationship was independent of and not moderated by age. The PPA differentiation index also predicted performance on a latent "fluency" factor derived from a neuropsychological test battery; this relationship was also age invariant. These findings suggest that two independent factors, one associated with age, and the other with cognitive performance, influence neural differentiation.