Normal aging modulates prefrontoparietal networks underlying multiple memory processes.

Fabio Sambataro, Martin Safrin, Herve S. Lemaitre, Sonya U. Steele, Saumitra B. Das, Joseph H. Callicott, Daniel R. Weinberger, Venkata S. Mattay
Eur J Neurosci. 2012-08-21; 36(11): 3559-3567
DOI: 10.1111/j.1460-9568.2012.08254.x

PubMed
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A functional decline of brain regions underlying memory processing represents a
hallmark of cognitive aging. Although a rich literature documents age-related
differences in several memory domains, the effect of aging on networks that
underlie multiple memory processes has been relatively unexplored. Here we used
functional magnetic resonance imaging during working memory and incidental
episodic encoding memory to investigate patterns of age-related differences in
activity and functional covariance patterns common across multiple memory
domains. Relative to younger subjects, older subjects showed increased activation
in left dorso-lateral prefrontal cortex along with decreased deactivation in the
posterior cingulate. Older subjects showed greater functional covariance during
both memory tasks in a set of regions that included a positive
prefronto-parietal-occipital network as well as a negative network that spanned
the default mode regions. These findings suggest that the memory
process-invariant recruitment of brain regions within
prefronto-parietal-occipital network increases with aging. Our results are in
line with the dedifferentiation hypothesis of neurocognitive aging, thereby
suggesting a decreased specialization of the brain networks supporting different
memory networks.

Auteurs Bordeaux Neurocampus