Hommet Caroline, Destrieux Christophe, Constans Thierry, Berrut Gilles
Centre Mémoire Ressource Recherche (CMRR) de la Région Centre et Médecine Interne Gériatrique, Hôpital Bretonneau et Université Rabelais, Tours, France.
Psychol Neuropsychiatr Vieil. 2008 Mar;6(1):49-56. doi: 10.1684/pnv.2008.0114.
Cerebral hemispheric lateralization is an old concept, particularly concerning language. In children, numerous arguments favour a left hemispheric predisposition for language, but do not exclude its strengthening during childhood. In the elderly, changes in the lateralization have been described. Two models were proposed to explain these changes. The right hemi-aging model is supported by behavioral studies and the age-related asymmetry reduction model is documented by brain imaging studies. We review the data supporting the two models. The significance of this age-related asymmetry reduction is questionable. The dedifferentiation view suggests that bilateral activation in older adults reflects difficulty in recruiting specialized neural mechanisms. Age-related asymmetry reduction may also be evidence of compensatory mechanisms and plasticity of the aging brain. It is useful for understanding physiopathology of cognitive decline and rehabilitation potential of the aging brain.
大脑半球的侧化是一个古老的概念，尤其是在语言方面。在儿童中，大量证据支持左半球对语言的先天倾向，但并不排除在儿童期语言功能会得到强化。在老年人中，已经描述了侧化的变化。提出了两种模型来解释这些变化。行为研究支持右半脑老化模型，而脑成像研究记录了与年龄相关的不对称性减少模型。我们回顾了支持这两种模型的数据。这种与年龄相关的不对称性减少的意义值得怀疑。去分化观点认为，老年人的双侧激活反映了招募专门神经机制的困难。与年龄相关的不对称性减少也可能是衰老大脑补偿机制和可塑性的证据。这对于理解认知衰退的生理病理学和衰老大脑的康复潜力很有用。
