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Aging and hemispheric cerebral lateralization

Centre Mémoire Ressource Recherche (CMRR) de la Région Centre et Médecine Interne Gériatrique, Hôpital Bretonneau et Université Rabelais, Tours, France.
Psychologie & neuropsychiatrie du vieillissement (Impact Factor: 0.89). 04/2008; 6(1):49-56. DOI: 10.1684/pnv.2008.0114
Source: PubMed

ABSTRACT 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.

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    • "In a cross-sectional study Goldstein and Shelly (1981) tested the neuropsychological functioning of 1247 participants, divided into six age groups (20s to 70s). The older as compared to younger age groups yielded a stronger decline in task performances, but this decline was more pronounced for tasks targeting the right than left hemisphere (see also Hommet et al., 2008). Cherry et al. (2005), comparable to the study by Reuter-Lorenz et al. (1999), performed letter-matching tasks, i.e., a physical and a name identity task. "
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