Department of Spanish, Linguistics and Theory of Literature (Linguistics), Faculty of Philology, University of Seville.
Spanish Language Department, Faculty of Philology, University of Salamanca.
Neuropsychology. 2023 Jul;37(5):501-518. doi: 10.1037/neu0000886. Epub 2023 Feb 2.
In this article, we reexamine the hypothesis of language retrogenesis, that is, the assumption that language change over healthy ageing mirrors, albeit inversely, language acquisition by the child. We additionally question whether this inverse pattern can as well be observed at the cognitive and neurobiological levels, and whether it can be informative (and a consequence, in fact) of how language evolved in humans.
We compare the language strengths and weaknesses signifying language acquisition and its eventual decay in healthy ageing. We further compare age-related cognitive and neurobiological readjustments during each of these two developmental stages, with a focus on brain areas involved in language processing. Finally, we delve into the evolutionary changes experienced by these areas.
We present evidence supporting the hypothesis of retrogenesis in two domains of language: the lexicon (lexical access, understanding of nonliteral meanings, and resolution of lexical competition) and syntax (understanding and production of complex sentences). Additionally, we show evidence that the brain areas supporting these complex tasks are late-myelinated in childhood and early-demyelinated during ageing. Finally, we show that some of these areas (such as the inferior frontal gyrus) are phylogenetically newer.
Language acquisition in children and language degradation/loss in healthy ageing follow the principle of retrogenesis, but mostly in domains that are cognitively demanding and that depend on recently evolved brain devices. Putting this differently, the components of language that emerged more recently appear to be more, and earlier, affected during ageing, as well as developed later over childhood. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
在本文中，我们重新审视语言逆行退化假说，即健康衰老过程中的语言变化反映了儿童的语言习得，尽管是相反的。我们还质疑这种相反的模式是否也可以在认知和神经生物学水平上观察到，以及它是否可以为人类语言的进化提供信息（实际上是其结果）。
我们比较了在健康衰老过程中标志着语言习得及其最终衰退的语言强弱。我们进一步比较了这两个发育阶段中与语言处理相关的大脑区域的与年龄相关的认知和神经生物学调整。最后，我们深入研究了这些区域经历的进化变化。
我们提供了支持逆行退化假说的证据，该假说涉及语言的两个领域：词汇（词汇获取、非字面意义的理解和词汇竞争的解决）和语法（复杂句子的理解和生成）。此外，我们还提供了证据表明，支持这些复杂任务的大脑区域在儿童期后期髓鞘形成，而在衰老期早期脱髓鞘。最后，我们表明，其中一些区域（例如下额前回）在系统发生上是较新的。
儿童的语言习得和健康衰老中的语言退化/丧失遵循逆行退化的原则，但主要是在认知要求较高且依赖于最近进化的大脑设备的领域。换句话说，出现较晚的语言成分在衰老过程中受到的影响更大、更早，并且在儿童期后期发育得更多。
