This review focuses on possible contributions of neural dedifferentiation to age-related cognitive decline. Neural dedifferentiation is held to reflect a breakdown in the functional specificity of brain regions and networks that compromises the fidelity of neural representations supporting episodic memory and related cognitive functions. The evidence for age-related dedifferentiation is robust when it is operationalized as neural selectivity for different categories of perceptual stimuli or as decreased segregation or modularity of resting-state functional brain networks. Neural dedifferentiation for perceptual categories appears to demonstrate a negative, age-invariant relationship with performance on tests of memory and fluid processing. Whether this pattern extends to network-level measures of dedifferentiation cannot currently be determined due to insufficient evidence. The existing data highlight the importance of further examination of neural dedifferentiation as a factor contributing to episodic memory and to cognitive performance more generally.

这篇综述着重于神经去分化对年龄相关的认知能力下降的可能贡献。举行神经去分化反应以反映大脑区域和网络功能特异性的破坏，这破坏了支持情景记忆和相关认知功能的神经表征的保真度。当与年龄有关的去分化的证据可作为对不同类别的知觉刺激的神经选择性或作为减少的静止状态功能性大脑网络的分离或模块化的证据时，这些证据是有力的。知觉类别的神经去分化似乎表现出与记忆力和体液加工测试表现呈负相关，年龄不变的关系。由于证据不足，目前无法确定这种模式是否扩展到网络级的去分化测量。现有数据突显了进一步检查神经去分化的重要性，因为神经去分化是影响情节记忆和更广泛地认知表现的因素。