Cognitive Neuroscience Division, Columbia University, New York, NY, USA.
Cognitive Neuroscience Division, Columbia University, New York, NY, USA.
Neuropsychologia. 2021 Jun 18;156:107856. doi: 10.1016/j.neuropsychologia.2021.107856. Epub 2021 Apr 19.
Aging is typically marked by a decline in some domains of cognition. Some theories have linked this decline to a reduction in distinctiveness of processing at the neural level that in turn leads to cognitive decline. Increasing correlations with age among tasks formerly considered independent have been posited, supporting dedifferentiation, although results have been mixed. An alternative view is that tasks become more, and not less, independent of one another with increasing age, suggesting age-related differentiation, or what has also been termed disintegration. In the current study, we investigated if the aging process leads to a loss of behavioral and neural specificity within latent cognitive abilities. To this end, we tested 287 participants (20-80 years) on a battery of 12 in-scanner tests, three each tapping one of four reference abilities. We performed between-task correlations within domain (pertaining to convergent validity), and between domain (pertaining to discriminant validity) at both the behavioral and neural level and found that neural convergent validity was positively associated with behavioral convergent validity. In examining neural validity across the lifespan, we found significant reductions in both within- and between-domain task correlations, with a significant decrease in construct validity (convergent or discriminant) with age. Furthermore, the effect of age on total cognition was significantly mediated by neural construct validity. Taken together, contrary to a hypothesis of dedifferentiation, these correlation reductions suggest that tasks indeed become more independent with advancing age, favoring a differentiation/disintegration hypothesis of aging.
衰老通常表现为认知某些领域的衰退。一些理论将这种衰退与神经水平上处理的独特性降低联系起来，而这种独特性的降低又导致了认知的衰退。有人提出，以前被认为是独立的任务之间的相关性随着年龄的增长而增加，支持去分化，尽管结果喜忧参半。另一种观点是，随着年龄的增长，任务彼此之间变得更加独立，而不是更少独立，这表明与年龄相关的分化，或者也被称为解体。在当前的研究中，我们研究了衰老过程是否会导致潜在认知能力中行为和神经特异性的丧失。为此，我们对 287 名参与者（20-80 岁）进行了一系列 12 项扫描仪测试，每项测试分别测试了四种参考能力中的一种。我们在行为和神经水平上对域内（与收敛有效性有关）和域间（与区分有效性有关）进行了任务间相关性分析，发现神经收敛有效性与行为收敛有效性呈正相关。在考察整个生命周期中的神经有效性时，我们发现无论是域内还是域间任务相关性都显著降低，随着年龄的增长，结构有效性（收敛或区分）显著降低。此外，年龄对总认知的影响通过神经结构有效性显著介导。总的来说，与去分化假说相反，这些相关性的降低表明，随着年龄的增长，任务确实变得更加独立，这有利于衰老的分化/解体假说。
