Marsolais Yannick, Perlbarg Vincent, Benali Habib, Joanette Yves
Department of Psychology, Université de Montréal, Montréal, Québec, Canada; Centre de recherche, Institut universitaire de gériatrie de Montréal, Montréal, Québec, Canada.
LINeM, Inserm, Université de Montréal, Montréal, Québec, Canada; U678, Inserm, Laboratoire d'Imagerie Fonctionnelle, Paris, France; UMR-S, U678, UPMC, Université Pierre et Marie Curie, Faculté de médecine Pitié-Salpêtrière, Paris, France.
Cortex. 2014 Sep;58:123-38. doi: 10.1016/j.cortex.2014.05.007. Epub 2014 Jun 8.
The relative preservation of receptive language abilities in older adults has been associated with adaptive changes in cerebral activation patterns, which have been suggested to be task-load dependent. However, the effects of aging and task demands on the functional integration of neural networks contributing to speech production abilities remain largely unexplored. In the present functional neuroimaging study, data-driven spatial independent component analysis and hierarchical measures of integration were used to explore age-related changes in functional connectivity among cortical areas contributing to semantic, orthographic, and automated word fluency tasks in healthy young and older adults, as well as to assess the effect of age and task demands on the functional integration of a verbal fluency network. The results showed that the functional integration of speech production networks decreases with age, while at the same time this has a marginal effect on behavioral outcomes in high-performing older adults. Moreover, a significant task demand/age interaction was found in functional connectivity within the anterior and posterior subnetworks of the verbal fluency network. These results suggest that local changes in functional integration among cortical areas supporting lexical speech production are modulated by age and task demands.
老年人接受性语言能力的相对保留与大脑激活模式的适应性变化有关，这些变化被认为依赖于任务负荷。然而，衰老和任务需求对有助于言语产生能力的神经网络功能整合的影响在很大程度上仍未得到探索。在本功能神经影像学研究中，采用数据驱动的空间独立成分分析和整合的层次测量方法，探讨健康年轻和老年成年人在语义、正字法和自动单词流畅性任务中，皮层区域之间功能连接的年龄相关变化，并评估年龄和任务需求对言语流畅性网络功能整合的影响。结果表明，言语产生网络的功能整合随年龄增长而下降，同时这对表现良好的老年人的行为结果有轻微影响。此外，在言语流畅性网络的前、后子网内的功能连接中发现了显著的任务需求/年龄交互作用。这些结果表明，支持词汇言语产生的皮层区域之间功能整合的局部变化受年龄和任务需求的调节。
